Fjd

Over the years I have gained some experience (e.g., either own, owned in the past, or had opportunity for extended listening session) with the following tube-based preamplifiers that I believe would fit well in a quality music reproduction system. I do not have much “shoot-out-type” comparison experience with this list as I tend to acquire based on the goals I have for the specific system implementation. The usual mentioned on the forum: Juicy Music Peach Juicy Music Blueberry (early version, "on-steroids" version, and extreme version) NOS Valves NBS preamplifier Examples not typically mentioned on the forum: Convergent Audio Technology (CAT) SL1 (IMO, one of the classics) Audio Research LS25 (6922 tubes) Audio Research LS25 Mk II (6H30 tubes) Audible Illusions Modulus 3A (IME, need quality tubes and eats weaker tubes for lunch) Manley Labs Shrimp ModWright SWL 9.0SE Cary Audio SLP98 (Line Stage uses 6SN7 similar to SLP05 and suspect sonic signature may be similar) Lamm LL2 Tube Research Labs (TRL) The Dude (IMO, nice implementation of 6SN7 tubes) Audio Research LS26 Audio Research SP10 (uses twelve 6922 tubes, and IME, needs quality tubes and it seemed to devour weaker tubes quickly) Audio Research SP11 Harman Kardon Citation I (complete restoration) Disclaimer: In relation to any forum member or anyone reading these threads and lurking; I cannot determine, and do not profess to know, if you will experience any system synergies; I have not performed any type of analysis to determine if my list of preamplifiers will be appropriately gain matched and impedance matched when used in any music reproduction systems other than my own. In addition, I do not remember the model of VAC amplifier that eth2 ultimately purchased and is currently using, I do not remember what loudspeaker (e.g., horns, direct radiators, combination, etc.) that eth2 is driving with the VAC amplifier, where the loudspeakers are located in his room, the dimensions of his room (length, width, height), how loud eth2 typically listens to music, what kind of music that eth2 typically listens to the most, and have not done any evaluation of preamplifier specifications in relation to eth2’s music reproduction system. Hopefully the list is informative and thought-provoking, prompts further research and investigation by anyone looking to purchase a tube-based preamplifier, and is not intended as insult or otherwise in relation to anybody’s choice in music reproduction system components!!!

Done, they are closed in Dave: Just want to be sure what 'they are closed in' means. Just because the backs are closed does not mean that they don't have to be in corners. Also the closed backs should be sealed at the top of the base bin to the corner with a triangle that would measure about 6.5 x 6.5 x 9 1/4". This was incorporated in later Khorns. Also don't forget 3rd path - Bob Crites - solid, economical upgrades Another consideration is how the work was done to close the back. I've seen a few where the person inserted the panels within the horn space itself, and essentially reduced the expansion rate of the horn. I haven't seen anyone take measurements before and after; therefore, I do not know how significant of an impact the, technically, smaller horn would measure. Here is a link to a very informative FAQ thread on obtaining the best imaging out of corner horn loudspeakers. https://community.klipsch.com/index.php?/topic/131163-corner-horn-imaging-faq/ Here is a link that looks interesting for another Klipschorn tophat solution. Does show a lot of measurements and the data sheet for the horns shows the polar response. This is the same guy that did the high-end crossover work for Volti Khorn upgrades (and I believe maybe for the Vitorra) and I've been thinking about having him design a passive for my Community M200 and VHF100 compression drivers (haven't finalized the horns yet). http://www.northreadingeng.com/baffle_insert/R2_Klipschorn_baffle_insert.html Main page with links to various custom work and photo essays. http://www.northreadingeng.com/ Here are the polar response curves for the horn from the datasheet. Note that North Reading uses the B&C DHM50 (a very nice compression drive) with the Selenium (JBL subsidiary) HM3950 horn. I've attached the data sheets below. . _ HM3950.pdf _ B&C DCM50.pdf

A fellow who knows hos stuff. Great job!!! I had a pair of the JBL 250tis, the pyramid looking ones in teak. They sounded great but were power hungry. Sent from my SM-N920P using Tapatalk I think you will find that the L100T will be on the "power hungry" side too.

They look a lot like JBL L100T

Agreed, that a comparison on an "apple to apple" basis appears to make sense and stress both amplifiers in relation to how you like to listen in order to evaluate how they perform in relation to your listening habits. However, this information now begs the question regarding how precise did you match the gain of each amplifier in your comparison? In my experience, some people tend to forget about "level matching" or "gain matching" when comparing amplifiers. Even very slight differences in gain between amplifiers can be audible as I have found that precise level matching can be more critical than most even realize. In certain situations a 1 dB difference can change a person's perception of an amplifier. In general, when gain levels are different, it seems that many will tend to conclude that louder music, even if it's just slightly louder, will almost always sounds better to them than the quieter music. The curiosity is killing me. What is this 25 watt push pull EL84 amplifier? In case you did not get it from what I wrote previously, Quick Silver horn mono's. TO BE PERFECTLY CLEAR...they sounded great. but $2,000 better than the yamaha rx A1030... not so much. If I did not have the yammy 1030, the horn mono's are keepers! AND the fact that I have the Yamaha RX 1030 is accidental. I had been wanting a Macintosh or Pass amp. I never thought I would have the money to buy one, and in fact did not ( at the time) . BUT i needed an amp. I looked on CL and this 1030 which I knew nothing about was for sale brand new used less than a week. I offered the guy $400 and he took it. I connected it to my ( new to me) lascalas and it sounded good. Thinking that tubes would sound better I saved up and bought the Big Ben. Since that is a buy it and you keep it, I kept it. Although it sounded a small bit better than the 1030, again it was not worth the money as far as sound improvement goes. Then, 2 yrs later, I got to listen to khorns. I was blown away by the improvement! BUT NOW the BB 6 watt SET just was not enough for the BASS when comparing to the yamaha 1030. So now you know the rest of the story. This thread lost me. Do you still have the Quicksilvers? If so, what 12DW7/7247 and power tubes are you using? Your preamp may not be optimal for the Mono's and that may be why the 1030 sounds good....the preamp section is matched to the power section. I have found, over the years, that a preamp and amp from the same manufacturer is they way to go. However, there are always exceptions. FloridaBoy makes an excellent point and it ties into the question I had asked earlier about gain matching the comparison amplifiers. Please keep in mind that the Quicksilver Horn Mono Amplifier has approximately 18dB less gain than Quicksilver's standard amplifier. I could not find specifications on the Yamaha 1030; however, I suspect that AVR receivers probably have higher gain figures and lower input voltages to achieve full power vs. the Quicksilver mono amplifier or tube amplifiers in general, which is one reason why I asked how you did your gain matching. I tried to find the output voltage of the Emotiva Stealth DC-1 and I believe this may be the first time I've seen a DAC that doesn't list its output voltage and impedance on its specifications page. I know that it is promoted as double duty as a preamplifier and these types of basic specifications are important in understanding the voltage gain of the preamplifier portion of the unit; however, maybe the primary purposes is DAC/Headphone amplifier since there appears to be plenty of headphone output data. For example, the XDA-1 specifications show a nominal output voltage of 1V RMS (balance output is more), for which 1V RMS would not be sufficient to drive the Quicksilver horn mono amplifiers to the full potential. While the Quicksilver horn mono amplifier has a nice input impedance of 100 Kohms, the Quicksilver horn mono amplifier has an input sensitivity of 6V. Also, did you use the Emotiva Stealth DC-1 with the Yamaha internal amplifier section (probably not the mismatch to the degree I suspect with the tube amplifiers) or the Yamaha internal preamplifier with the Yamaha internal amplifier (where you would have no mismatch)?

The F3 is really a nice amplifier and I remember that I enjoyed reading your review of that amplifier. Lately I’ve been trying to match components (whether tube or solid state) that have very low noise floors and low distortion levels, specifications not solely achieved through high levels of negative feedback. Although I’m still a few months away, next on deck is what appears to be a well-engineered line stage developed on the DIYAudio forum using a 4P1L tube that is actually a pentode tube but has direct heated filaments and wired as a triode resulting in a very linear tube with very low noise levels for the line stage circuit. The 4P1L tube line stage will provide 7dB of gain and I plan to see how it matches up with my First Watt F3 amplifier that has 12.5dB of gain. This line stage is not necessarily an easy implementation as the 4P1L can be very microphonic, but once the various “triggers” that cause a tube to ring are engineered out of the implementation and the 4P1L is wired as a triode, it looks like it will be a line stage that meets the current criteria of low noise and low distortion. It should be fun. In addition, while by no means an absolute, I have given a lot of thought about the aspect of people generally concluding that the lower watt amplifier has the "better" sound. For example, I can't count the times I've read where a person has a 300b then listens to the 2A3 and concludes the 2A3 sounds better. Then the 45 comes along compared to the 2A3, and guess what? Of course, the 45 has the better sound. I've read similar conclusions about the 71A tube and the 1626 tube in the Darlington circuit. Etc., etc. etc. What does this all mean? Is there any correlation or validity to the aspect that in each instance the lower power amplifier is ran much closer to its maximum, thus generating additional second harmonic distortions? I know this is general and not all amplifiers have the same level of distortion at full output, but it does seem to be an interesting phenomena to consider. Somewhere I had read a signature on one of these audio forums where the signature said, "shape the sound." Personally, as much as I use "accuracy" in attempting to evaluate gear, I also love having choices and assembling “situational systems” to meet different listening objectives. Frank, thanks for your insightful contributions to this discussion! How do you find the time to write such long explanations? As to the conclusions that some have made about the best sounding tubes, they are really invalid unless the same output xfmrs were used, at the very least. And, there are a multitude of other variables which can affect sound, such as the frequency response created by specific values of coupling or bypass caps, the amount of nfb used (if any), the output tube's plate resistance, characteristics of the driver, and so on, that it becomes impossible to create a really controlled comparison. As to lower power amps sounding better than their higher power counterparts, I can only say that in my experience the best sounding units are those which employ tubes designed for service in the ubiquitous table radios of days gone by. And they maintain this amazing sound whether used at a fraction of their output power, where the distortion is extremely low, or closer to their maximum. I have no explanation for this; yet, a 6V6 for example, using the same output xfmr and circuit characteristics, and matched to the same power output, doesn't sound as good to me or many others who were listening. As to shaping the sound, I know few who don't do that in some fashion. Every person for whom I've ever restored a vintage amp with tone controls uses them to create the sound they prefer! Every custom amp that I design and build has some means of adjusting its sonic characteristics to suit individual taste, speakers, and room characteristics. So, what constitutes "accurate reproduction?" There's no point in having equipment with the proverbial, flat, "dc to daylight" frequency response if it sounds like garbage to the person who listens to it. I'd rather listen to distortion which allows me to enjoy music to its fullest, than no distortion which sounds like finger nails scraping on a chalkboard. Speaking of distortion, you mentioned the 1626 Darling amp. I once ran loadlines for that tube and, with the recommended circuit parameters, I think the 2nd harmonic distortion was around 15% at full output. Yet, folks who use those amps usually say that they have never had a more enjoyable listening experience......... Maynard Lots of stuff circling in my head and since I don’t have the time to write often, when I do write, I like to make the most of it. Makes sense, and I agree that there are an exponential range of variables that will never be controlled in evaluating the audio reproduction chain or in trying to determine if there are explainable reasons why certain gear is chosen over others. From the outside looking in, we just don’t have enough information, and I suspect, the person making the selection has not even truly identified the reasons “why” themselves. Part of my intent with many of these posts is to draw out the specific experiences from the very diverse backgrounds of our forum members. While I often lay out thoughts and concepts that can perk the interests of the technical people with the skills and understanding of electronics, I also try to give a few thoughts on the music aspect itself. Many times the posts I read in the threads have led to a whole new avenue that I choose to explore resulting in new insights that may be of some relevance to others. In other instances, such as in the OP’s original quest, I hope the different views and experiences expressed will help raise additional questions and awareness, to help the person better evaluate if they have made the correct correlation for the issue. I believe that the variables you have outlined often do not make it to a level of conscious consideration, similar to Gil’s post below where I responded to Gil that “there is iron in your words,” (although, I’m not sure anyone actually caught the pun in connection with quoting “Ten Bears” and all of the iron in tube amplifiers using transformers). To borrow an iconic phrase from Ten Bears, "there is iron in your words." Yep, I just got done watching the movie "The Outlaw Josey Wales" and decided to read a little. You sure outlined way too many variables to even think about all of the potential impacts when considering the audio reproduction chain as the initial capture of the performance all the way to the output from the speaker in a home listening environment. The multitude of variables that cannot be controlled or even identified being so overwhelming, relates to the reason why I tend to post that I firmly believe that the ear (even an “untrained” ear) can detect very small differences that seem very inconsequential on the surface; and I certainly cannot find fault with those that just use their ears and go with what provides the listening experience they are looking for. However, I try to remind that although the ear can detect very small differences, the brain may not exactly know what specific aspect of the music reproduction chain to attribute the difference. Actually, I never really liked the word “accurate” since, there again, 15 different people will have 15 different definitions of “accurate.” However, long before this book/movie on “50 shades of grey,” at least for me, I tended to believe audio reproduction was there first, with “50 shades of realism” and anyone should be able to find their own comfort zone on this type of continuum without criticism of others. 50 shades of realism may help negate the negative connotation attached to “inaccurate” and (going with my earlier high-definition TV analogy) we can decide for ourselves if we want the “cartoon” version of Daphne Blake of Scooby Doo fame, or if we want something with a touch more realism, such as the Sarah Michelle Gellar version. However, even 50 shades of realism has its flaws. For example, it seems that today the ideas about music are not the same as when I was a kid and there may not be as much exposure to live music that conveys presence through voice and acoustical instruments alone. More and more, “we” as a whole appear to be synthesizing sounds and music that seem to have no actual real counterpart in the “live world” and during this avenue of change we seem to be losing the benchmark perspective of “realism” in relation to the “live event.” There was a thread on gaining “perspective” with audio gear by comparing with other gear and many in that thread seemed to shoot down my thoughts on developing perspective by gauging reproduced acoustical music against a live acoustical music event. I thought either none had actually been to a live acoustical music event or maybe my posting had been translated into a foreign language, I just don’t know. Well, that is another topic for another day and back to my aspects of realism. At least for me, the concept of 50 shades of realism isn’t really much different than PWK outlined in “Dope From Hope, Vol 4, No. 3 August 21, 1963” where PWK indicated that “In quality or accuracy, all loudspeakers err by greater or less amounts. Comparison between them is not the best way to evaluate them. Comparison with live sound would be much better when and if possible. Then one would not judge which sounds best but which sounds most like the original. If the original sounds bad, then surely, so should the reproduction.” Let’s expand PWK’s views on “comparison with live sound.” The most common benchmark or quote that I read is related to Harry Pearson (of “The Absolute Sound”) where his stated benchmark was “the sound of live, unamplified music occurring in real space.” In this regard, although “real space” can mean a variety of settings as different as a concert hall compared to outdoor settings, we are looking at music and voice from actual acoustic instruments and people singing without electronic amplification and without any sound reinforcement systems. To borrow a term used by our own Dave Mallette and apply it here, we may be getting closer to the musical “TRVTH” in evaluating the realism of the reproduction. Now let’s look a little closer at “shades of realism.” For example, when thinking about shades of realism, how well can a person’s audio system get the “general” beat, rhythm, melody and harmony correct or resolve enough detail and cues from the recording in relation to the actual score of the musical composition (of course, for this section I’m assuming the piece is played to the original score and captured in the recording). On a side note, ever notice how many people “loosely” use the acronym PRAT for the comparison of how one “loudspeaker sounds in relation to another type of loudspeaker” instead of evaluating the realism of the music reproduction in the context of the inherent PRAT (pitch, rhythm & tune; or pace, rhythm & timing – take your pick) that is reproduced in relation to the live musical event that closely follows the actual score of the musical composition? I use the term “generally” because there will be systems that do these aspects much better than others. For example, in something like the melody that essentially relates to the notes played at different pitches or even repeated pitch may not be entirely distinguishable, but different systems will still tend to resolve enough detail to distinguish the pitches or maybe enough cues related to duration or rhythm that should help a listener recognize the melody. Regarding rhythm, since it will not always represent the ‘periodic beat’ over the entire musical score, can the system resolve enough detail to determine that a guitar may actually be playing the opposite of the beat? How well does the system resolve detail in relation to the harmony where the 'lead' voice and instruments playing melodies can be distinguished from other voice and instruments that accompany the lead but are doing something else (e.g., essentially hearing the detail of different notes played at the same time)? How well can the system resolve the distance between notes where a listener can determine whether the harmonic relationship is one of consonance or dissonant? Is there enough information being reproduced in enough detail where a listener can actually feel the sense of relaxation or feel the sense of tension that may be scored as part of the harmony? How much realism is there to the fundamental frequency and overtones? Does the timbre, tone quality and tonal accuracy of the instrument sound real? I’m straying to amplified music a bit, but I can’t distinguish when a Gibson SG guitar is being used from evaluating the timbre, but my brother can pick out the Gibson SG every time. I love the differentiation and nuance in the various instruments related to the individual bass notes that gives me a sense of “realism” with the Klipschorn loudspeakers vs many speakers that seem to only produce the sense of “one note” bass. There are many more aural cues that may be in the recording, but I tend to stop around this point. I don’t feel the need to hear the ambient aspects of the auditorium where the music was recorded, since a certain level of “realism” in my “listening space” is fine. I also, do not feel the need to hear the sweat dripping from the performer’s forehead onto the soundboard of the acoustic guitar. I just do not find these things important; however, I realize that there will be others that seem to and that’s fine with me. As a final test to determine if my system can resolve a portion of the points above for a fairly nice representation of “realism” in the music, I would have little get-togethers with some of these “well-trained ears” that I know, and often times, when one of them is familiar with certain nuances of the live music that may not generally be heard in reproduction systems, they will tend to pause and state something like, “wow, that recording sounds pretty real” and often not even realize why. Some of the nuance in live music I can hear and identify, much of it I cannot. For example, I cannot tell you the wood used to make the soundboard on an acoustic guitar or the wood used to make the piano by the timbre of the sound of the instrument being played and certainly would not be able to identify in a recording, but seem to have found a couple of friends over the years that can. None of what I can hear or cannot hear impedes any of the enjoyment I derive from music, and ultimately, while I like to experiment and test in order to increase my understanding of things, I try not to make anything about this an obsession. .

Why would Tom mind making more cases??? That's what I was thinking. I'm sure Tom enjoys the work. Although, I think A1UC is tired of discounting new cases far below retail prices since he isn't one of those unauthorized dealers getting them at discounts.

I deleted everything but the zip code from the original post. The zip code is Staten Island, NY. Funny, but I move out of the area and all kind of deals come up.

I haven't had much time to follow this transition since I wrote the post below and will be interested in the actual experiences people have when they start using the fiber optics services. Fiber optics is a very logical conclusion since it can provide exponential bandwidth over what was previously possible with copper; however, as you noticed, we are still dealing with the massive corporations and it will be difficult to determine what will ultimately be provided to the end user and at what cost.. Quality IPTV is coming on strong so much sooner than most realize. However, I believe that there is still some “posturing” going on over the actual infrastructure that will deliver all of the “content” and “streaming services” that needs to resolve itself before we see a large scale adoption. I do believe it will be here and in place before the driverless cars in the other thread and once the infrastructure falls into place and becomes more efficient and profitable, you will see many more content providers and more equipment providers enter the marketplace. If interested in why I believe Google may play a large role in the backdrop needed for this next revolution or frontier of internet technologies, search “dark fiber” and look who has been quietly buying all of the unused fiber optic cable around the world. You will find that Google and Facebook have been buying much of the unused fiber optics. Google started purchasing on a large scale back in 2005 and now owns over 100,000 miles of fiber optic cable routes globally. The demarcation point was probably the “Telecommunications Act of 1996,” which is described as an “Act to promote competition and reduce regulation in order to secure lower prices and higher quality services for American telecommunications consumers and encourage the rapid deployment of new telecommunications technologies.” Before 1996, the telecommunication companies were regulated; however, with the Internet and new technology on a steep and consistent spiraling rise toward the sky, the government "handed over" the regulation of the telecommunications companies to regulate themselves and develop the U.S. data infrastructure. After about $25 billion in tax breaks, this extensive fiber optics network was developed; however, the dot-com crash brought many of these companies down and many underwent mergers and bankruptcies, essentially, eliminating these companies before they even had a chance to set up the necessary hardware to interact with the fiber-optic lines. Essentially, there are hundreds upon hundreds of thousands of miles of “dark fiber” related to the network of fiber-optic cable built in the late 1990s and early 2000s. During that period of time, telecom giants such as AT&T and Verizon (formerly GTE) bought up many of these companies for pennies on the dollar (including the respective fiber optic networks) and the interesting aspect here is that both had huge vested interests in keeping copper wires around for a while longer, since copper wire was used by their "cash cows" known as DSL and wire-line telephone services. For years now this expansive network of ultrafast cabling has gone essentially unused with a huge upside of untapped potential. Only recently has the “copper cash cow” essentially run its course where you are finding that these companies have begun offering consumer-level fiber-optic television, phone and Internet services. Essentially, copper is fast becoming obsolete due to demand that is driven by "skyrocketing Internet video traffic, requests from the financial sector for ever-faster trading connections, and soaring mobile phone use - which has to be tied into landline networks." This brings us back to Google and Facebook buying up huge portions of unused fiber optic cable that the huge telecoms don't own. However, while the “faces will change,” we all will still be dealing with massive corporations in the end. Progress at its finest! http://www.wsj.com/articles/SB10001424052702303863404577285260615058538

Some would posit that the magic of the original performance was bastardized the moment the sound was captured by the mics, in which case a little tube amp processing embellishment on playback is a-ok. Accuracy to the original is a laudable goal, but never achieved. If that's the goal, then go by the book: only use amps with low distortion, low output impedance, and enough power that clipping is never an issue, and enjoy the resulting dry, clinical sound. Or try one of Maynards designs, which definitely add a bit of wetness and real-life-resembling spatial qualities (IME only SE amps do this trickery). Bi-amping may work, provided the amps don't have too much divergence in their sonic character. A lyrical sounding SET up top may audibly clash with a tight, dry ss amp on the woofs. That was my experience, at least. The puny amps weren't as strong down low, but there was a certain roundness of tone from the tubes that was lost with ss. Another experience I've had is that the small tube amps seem to be able to handle eq (bass boost) rather well, with less handicapping of overall power than I expected. Have you tried to simply eq your bass? I’m curious if the second harmonics are really inaudible or a contributor to the “bloom” that characterizes a SET amplifier with higher levels of distortion or if it has anything to do with the air gap transformers used in single-ended designs? I have to think that someone has tried to measure it somewhere for a better idea as to what may be audible for some type of average level hearing acuity. In another post I had expressed a view that, in general, I believe that most manufacturers (especially those making mass-produced products) will go to extraordinary lengths to “claim” accuracy, for what appears to be done in order to give consumers some level of “assurance” that they are buying products that are “accurate.” With human nature being what it is, I believe that the general consumer doesn’t want their friends (or anyone on the internet) questioning them on why they bought an “inaccurate” stereo system (whatever “accurate” or “inaccurate” may actually mean). Peer pressure or maybe advertising pressure at its finest. I personally believe that in most situations, you can easily find that most systems are just not accurate; and, in those indelible words of Bill Murray spoken in the movie Meatballs, “It just doesn’t matter.” Where I believe that certain aspects of the problem comes into play, is all of the “conditioning” that we continually go through for the goal of 'accuracy.' I see that some in this thread seem to be freely admitting that maybe accuracy isn't the goal; and in most situations my goal is not necessarily “accuracy,” at least not for every situation. However, in general, I encounter very few individuals that are able to admit to themselves that maybe a significant reason why they enjoy a certain amplifier is because it has its own 'sound' that works well with their speakers and works well simulating what they find important in a music listening experience. As you seem well aware, there is a lot of internet chatter everywhere regarding second harmonic distortion and it is up to debate (or some type of testing) whether these distortions are audible or not; however, very few will readily admit this is most likely an amplifier “inaccuracy” (by definition?) in the form of its harmonic distortions. Of course, I suspect that there will be people reading this and thinking to themselves, “Well this is a bunch of BS, “my” amplifier doesn't distort like that...my amplifier is as accurate as they come.” However, I would hope they have enough of an open mind to do a little research on the topic (I think I’ve given a good start here and in the high power amplifier thread); and then ask themselves if they really know with certainty that this is the case” or “are they making an assumption that the amplifier cannot be inaccurate because they enjoy it, therefore, it must be “accurate”? I don’t know, just more food for thought at this point. From another perspective, the recording of an instrument will have captured the actual overtones/harmonics that the instrument originally produced in the live session. Now feed the signal of the recorded instrument into the amplifier and given the levels of harmonic distortion of the amplifier, it seems reasonable that the distortion will in effect become a new fundamental that has been added to the harmonics of the original instrument. Is the amplifier "accurate" or "inaccurate"? Of course, I know what Bill Murray would say. I have a few more items tagged for reading related to air gap transformers vs. transformers in general; however, in many respects, it seems that the amplifier that 'blooms' typically has a higher level of second order harmonic distortion and as a result will typically be creating “new” harmonics of what was originally a harmonic rather than only reproduce the harmonics of the original instrument on the recording. In addition, while by no means an absolute, I have given a lot of thought about the aspect of people generally concluding that the lower watt amplifier has the "better" sound. For example, I can't count the times I've read where a person has a 300b then listens to the 2A3 and concludes the 2A3 sounds better. Then the 45 comes along compared to the 2A3, and guess what? Of course, the 45 has the better sound. I've read similar conclusions about the 71A tube and the 1626 tube in the Darlington circuit. Etc., etc. etc. What does this all mean? Is there any correlation or validity to the aspect that in each instance the lower power amplifier is ran much closer to its maximum, thus generating additional second harmonic distortions? I know this is general and not all amplifiers have the same level of distortion at full output, but it does seem to be an interesting phenomena to consider. Somewhere I had read a signature on one of these audio forums where the signature said, "shape the sound." Personally, as much as I use "accuracy" in attempting to evaluate gear, I also love having choices and assembling “situational systems” to meet different listening objectives. Disclaimer: As used in my various posts, "concert-level," “115db SPL at the listening position,” “SET,” “Push-Pull,” “solid state,” “harmonic distortion” and other terms were not used or meant to be taken as mandates or absolutes; and not used or meant to be taken in any disparaging way by any forum member or by anyone reading these threads and lurking. As always, please note that the information presented by this author is meant for fun, hopefully informative and thought-provoking, and is not intended as insult or otherwise!!!

Really really great and sensible post. I commend you on your time spent doing research! Thanks! I shortened the original post to save on bandwidth. Here is what I believe to be a worthwhile read. At the link is an issue of “High Fidelity” magazine from December 1956 and Page 4 starts an article related to G.A. Briggs of Wharfedale Loudspeakers giving a demonstration on October 3, 1956 of “live and recorded music” in Carnegie Hall to about 2,500 in attendance. Page 9 starts a section of the article where PWK in conjunction with Gray Research and Development Company did a smaller scale demonstration of Klipschorn loudspeakers on October 9, 1956 in Hartford, Connecticut at the Bushnell Memorial Hall. I find it interesting to read an article that was written so close to the actual event. http://vintagevacuumaudio.com/vintage-magazines/high-fidelity/1956-12-high-fidelity.pdf Actually, I’m not in this trying to correct misinformation on the internet, that’s an impossible goal. However, I do believe that if people are genuinely interested in the technical aspects that PWK has considered in developing the Klipschorn and the design decisions and trade-offs that were considered, PWK's Dope from Hope series is well worth the time it takes to read. It seems that a few of the attachments to certain documents on the Klipsch main website may be missing, but with internet search capabilities, I was able to find most hosted on other websites. In many respects this is a fun mental exercise in trying to understand the decisions PWK made and the actual trade-offs that he had considered. Of course, the posting of PWK’s table outlining amplifier wattage in the “high power amplifier for heritage” thread and some of those comments really got me thinking about a few things. I guess in that thread at the link below I was researching how PWK concluded that two watts were sufficient to fill a room with concert-level peaks inherent in the music, not trying to figure out if he had a preference or recommendation. https://community.klipsch.com/index.php?/topic/163148-high-power-amplifiers-for-heritage-speakers/ When revisiting all of PWK’s writings and other publications that were written during that time, it became clearly evident that PWK was, first and foremost, an engineer building a high-quality high-performing loudspeaker capable (not to be confused with “mandatory that everyone use it this way”) of producing concert-level sound of 115dB SPL at the listener position. In “Dope From Hope, Vol 4, No. 3 August 21, 1963” PWK indicated that “In quality or accuracy, all loudspeakers err by greater or less amounts. Comparison between them is not the best way to evaluate them. Comparison with live sound would be much better when and if possible. Then one would not judge which sounds best but which sounds most like the original. If the original sounds bad, then surely, so should the reproduction.” In “Dope From Hope, Vol 5, No. 1 Feb. 24, 1964” after the proper loudspeaker selection, PWK outlines that room acoustics are the second most important/critical aspect in achieving good audio. I did not have any pre-conceived notions of what I may find, just that I would post what I did find. In all of my reading I found no evidence that PWK was promoting one type of amplifier topology over another, or even made any comment regarding that he liked the “sound” of one type of amplifier topology over another. In fact, liking the “sound” of an amplifier seems like it would have been counter-intuitive to how he believed a loudspeaker should be evaluated (excerpt above from Dope From Hope, Vol 4, No. 3 August 21, 1963). Dope From Hope, Vol 16, No. 3 March 1977 dedicated an entire issue looking at the distortion that Dr. Matti Otala found in the early solid state amplifiers and did offer thoughts on the impact to the music reproduction. This may be the only place where PWK did a general comparison of tubes vs solid state, where he concluded that Transient Intermodulation Distortion (TIM) found in early solid state amplifiers impacted the sound and needed to be engineered out of solid state amplifiers. The quote verification search actually started last fall when I wanted to add a legitimate PWK quote to my signature and was trying to verify several audio related quotes that I found interesting and were often attributed to PWK. During the quote verification process, I find it rather staggering how many quotes on the internet are either incorrect or never made, attributed to the wrong individual or have been completely skewed out of context from the context in which the author had said or written the words. Regarding the 5 watt amplifier quote, since I could not find a shred of evidence he said it or the context in which he may have said it, I had hoped Maron (most recently "Zako" on the forum) could provide some insight; however, with his passing away last October (may he RIP), I believe that the forum lost the “last gray haired eminence with ties to all of PWK's wrecking crew of tin foil hat experimenters.” If the quote was actually said, given that PWK was an engineer designing and building loudspeakers (with a design goal of reproducing concert-level sound of 115dB SPL) and outlined why he believed that room acoustics were the second most important/critical aspect in achieving good audio (Dope From Hope, Vol 5, No. 1 Feb. 24, 1964), I suspect he may have been criticizing the amplifier manufacturers of his time. Disclaimer: As used in my various posts, "concert-level," “115db SPL at the listening position,” “SET,” “Push-Pull,” “solid state,” “harmonic distortion” and other terms were not used or meant to be taken as mandates; and not used or meant to be taken in any disparaging way by any forum member or by anyone reading these threads and lurking. As always, please note that the information presented by this author is meant for fun, hopefully informative and thought-provoking, and is not intended as insult or otherwise!!!

Here is a combination that I found to be a fun experiment. The First Watt F4 (I would suggest reading the manual Nelson Pass has posted to the First Watt web site) in a "bi-amp" setup and drive it with a single-ended tube amplifier as Nelson Pass describes in the schematic below (and his operating manual) where the single-ended tube amplifier directly drives the mid/tweeter and drives the F4 that in turn drives the woofers. A single F4 will give 25 watts (50 watt peak) per channel into 8 ohms and 40 watts into 4 ohms. However, wired as a mono block the F4 will give 100 watts. The First Watt F4 has zero voltage gain, which eliminates the need to "gain match" with the single-ended amplifier. Essentially, one way to think about the F4 is having a "component" approach to your voltage gain and your current gain. Basically, the F4 can be thought of as a refined power follower, it will essentially push the same voltage out that you send into it, but it will feed much more current through the load than the single-ended amplifier, if, or when, needed. I see this same concept of tube for voltage gain and solid state (usually mosfets) for current used in some of the high-end headphone amps too. As I mentioned, in another set-up that I experiment with, I essentially use my DHT SET amplifier as the "voltage gain stage" directly into the F4 and try to maximize the aspect that the F4 is such a simple Push-Pull circuit with no negative feedback, very low distortion levels and only a miniscule 50uV noise level. In this regard a lot of the characteristics of the DHT SET amp that I find very favorable will come through. I like to think of it kind of like a "SET on steroids" in some ways, but also noting that it looses only some very small aspect of that intimacy that DHT SET can provide in those near-field lower-level listening sessions. On an important side note, there are various implementations of "adaptors" out there as the DHT SET output will need to be adapted to the RCA input of the F4. Also, due to the F4's high input impedance (47,000 ohms), a resistor (~ 20 ohm, 5 watt resistor, but some have used anywhere from about 15 ohm - 22 ohm depending on how they like the sound) is needed across the SET outputs since the SET only "sees" the F4 and not the speakers. On DHT SET amps with multiple taps (i.e. 4, 8 or 16 ohm) there seems to be some diversity on which tap sounds best; however, I suspect that is more related to system synergies. The catch? The F4 has reached the end of the 100 unit run that Nelson Pass had set and is no longer available new leaving the option of watching the used secondary market or building a DIY clone. If you find this interesting, the F4 is well-documented on the DIY Audio site with build guides and a lot of troubleshooting information. In addition, the DIY store stocks most of the hard-to-find parts.

Agreed, that a comparison on an "apple to apple" basis appears to make sense and stress both amplifiers in relation to how you like to listen in order to evaluate how they perform in relation to your listening habits. However, this information now begs the question regarding how precise did you match the gain of each amplifier in your comparison? In my experience, some people tend to forget about "level matching" or "gain matching" when comparing amplifiers. Even very slight differences in gain between amplifiers can be audible as I have found that precise level matching can be more critical than most even realize. In certain situations a 1 dB difference can change a person's perception of an amplifier. For example, in certain listening rooms that tend to allow a speaker to "bloom" with reflective surfaces and very little absorption, a person could fairly easily detect a 1 dB difference in output level between amplifiers. From another perspective, even with "gain matching" the lower powered single-ended amplifiers are working much harder where the single-ended amplifier is being run much closer to its maximum power ratings, which tends to mean that they are distorting more. The lower the power output of the amp, the more many people make them work extremely close to the amplifier limits and the more it will be distorting. I believe that it has been fairly well documented by Nelson Pass and others that distortion of the 2nd harmonics variety, in general, tend to be very pleasing to the ear and the correlation has often been made that perhaps the listeners that love the 'blooming' midrange are actually loving the additional harmonic distortions caused by running the amp fairly hard relative to its power output. Given the above, on a side note, as I've posted multiple times in this thread and other threads, there is nothing wrong with liking that, it is a persons personal taste after all. I don't make it a habit to judge another person's personal taste and I sure hope that readers do not jump to unfounded conclusions reading my posts. Those that take the time to read my posts and in some instances ask clarifying questions, know that I look at the music listening experience from a "situational" standpoint and try to match a system to the mood of the environment; and have run a very large variety of amplifiers and have a fairly large stable of single-ended direct heated triode and single ended pentode amplifiers too. In addition, since you brought up scientific methods, I firmly believe that the ear (even an “untrained” ear) can detect very small differences that seem very inconsequential on the surface; and I certainly cannot find fault with those that just use their ears and go with what provides the listening experience they are looking for. However, from another perspective, my point regarding gain matching is that although the ear can detect very small differences, the brain may not exactly know what aspect of the music reproduction chain to attribute the difference. In general, when gain levels are different, it seems that many will tend to conclude that louder music, even if it's just slightly louder, will almost always sounds better to them than the quieter music. Now for those reading the thread that may decide to go the measurement route and do some gain matching for amplifier comparison, I would recommend using a volt meter that will measure down to 0.001 volt AC if possible. I have gone back and forth in my mind, while playing the relevant test tones, which is the best place to measure. For example, if measuring at the output of the power amp or if the measurements should be made at the speaker terminals. I've been thinking that maybe both places, which will allow you to understand the voltage drop for each speaker wire or channel. For example, when you measure at the amplifier, in most instances you will find it to be slightly more voltage as the speaker wire resistance is not part of the measurement. Now if you decide to measure the voltage at the speaker connections, in most cases you will find it to be slightly less voltage as compared to the measurement at amplifier connections due to a certain amount of voltage drop across the speaker wire. Now with the test tones playing over the two signal paths, I would shoot for a level match within about 1% or a level match of about 0.1 dB difference. Although, given what I suspect to be the perceived difficulty of the above, I cannot necessarily find fault with those that just use their ears and forego the measurements, go with what provides the listening experience they are looking for, and attribute the difference to whatever the brain tells them too.

Since you bring up PWK, could you tell me some of the SET amps he used? Or for that matter any tube amps that he used later in his life when SS became a viable option to the tubes? Forgive my ignorance but I am only aware of his early favorite (modded Brooks 12A 2A3 PP of 10W. or so), and latter the various pro SS amps from Crown, BGW, etc. I think we have somehow created our own “red herrings” that we are now chasing upstream. In many of the articles where we have jumped to conclusions that Paul was promoting one type of amplifier topology over another, our conclusions appear to be incorrect and he is really expounding upon how well-engineered his Klipshorn speakers are. When it comes to amplifiers, I believe that PWK was primarily pointing out a simple mathematical relationship and facing an economic reality of the times he lived. After reviewing a multitude of evidence for which I have outlined a few key points in more detail below, I tend to hold the view that I don't think PWK can be used as an advocate of low powered SET amplifiers any more than he can be used as an advocate for mid-power solid state amplifiers. Although, in one of the “Dope From Hope articles” he does state that “In a typical living room or small theater, our present all-horn systems offer concert-hall levels with a mere 10 watts peak input.” There again, PWK specifically stated 10 watts, not 5 watts, and I believe his statement was a tribute to the engineering of the loudspeaker in that it could reproduce concert-level SPL with fairly low power (e.g., doing the math), not an endorsement of any specific amplifiers or amplifier topologies. The simple fact of the matter was, is, and always will be, the Klipschorn speaker efficiency allows a person to use very low-powered amplifiers if that type of amplifier meets that person’s listening requirements, regardless of whether that choice is SET, SEP, Push-Pull, solid state, or otherwise; and as I have noted in other posts, the Klipschhorn will reveal very quickly if the amplifier sucks or the source sucks or both suck. After spending a very substantial amount of time revisiting the “Dope From Hope” articles and various other documentation (including the pages of “Klipschisms, quotes and anecdotes" attributed to PWK on the main website), I also could not substantiate that PWK explicitly voiced, or had written the quote often attributed to him that "What this country needs is a good 5 watt amplifier." Without specific credible evidence, especially given that PWK was looking for concert-level reproduction of 115dB SPL at the listening position, I'm now wondering if the quote is a type of urban legend that has proliferated over the internet, similar to the Robert Hartley situation I describe below (e.g., in PWKs situation outlined below, 5 acoustic watts = 20 amplifier watts, not 5 amplifier watts). Jim Hunter, just where are you when we need you? Since the written records appear to clearly show that PWK loved his push-pull 10 watt per channel Brook 12A amplifier, he may have actually been complaining that amplifiers of his time were not powerful enough, in addition to not being good enough. The written information appears to show that, in addition to PWK liking the Brook 12A amplifier at first, he then moved to a variety of mostly solid state amplifiers in the range of approximately 60 watts per channel. I have also found references where he used a lot of different brands including Crown (D60) and BGW (model 100). An interesting side note with the Klipschorn history in relation to the Brook amplifier is that Paul (and Brook) collaborated to squeeze more [power] from the 12A amplifier (a 2A3 push pull design) and developed modifications to address some bass deficiencies that were revealed by the Klipschorn speakers. The modification subsequently became a factory mod available to optimize the amplifier to the Klipshorn and was given the catalogue number of “12A3-KI.” I have also found that there are many other references in his literature where he recommended 20 watts per channel amplifiers as a minimum for Klipschorns. Keeping in mind that one goal that PWK had often articulated in both verbal and written form, was that his loudspeakers were capable of reproducing concert-level sound of about 115dB at the listener's position, and here is one such reference from the "Dope From Hope" Vol. 14, No. 2 May 1974 titled "Power Ratings." "[''What size amplifier shall I buy?" This is really the first of two questions. The answer, applied to KLIPSCH speakers, would be a maximum of 100 watts (sine wave rating) per side. If a higher power is used, precautions may be needed to prevent speaker damage. Crown suggests a one ampere fuse for each channel. The second question, I think we can assume, is fishing for a realistic relation between sound pressure level and amplifier power. Accept the figure that 115 dB peak sound level pressure at the listener's ear will be as loud as what you would hear at a live concert. (A sound level meter would read 103 dB at "maximum" swings, because a V.U. meter has a "delay" or "lag", and instantaneous peaks are about 13 dB higher than the meter reading peaks). In a typical 4000 cubic foot listening room, this requires 40 peak amplifier watts to feed a group of high efficiency loudspeakers: assuming this to be 2-channel stereo, 20 peak watts per channel or 10 watts average sine wave power rating per side is required. For a low efficiency speaker (of the typical so-called air suspension type) over 100 times as much amplifier power would be necessary: that makes over one kilowatt of sine-wave rated power for each channel.]" In the "Dope From Hope" (Vol. 8, No. 1 July 11, 1967) article titled "Guarantee Void" PWK stated that, "[back in the good old days of 10 and 20 watt amplifiers it was uncommon to experience loudspeaker failures. When 75 watts became common, occasional tweeter failures began to occur. Then with the advent of large solid-state amplifiers with their 240 instantaneous power peaks, tweeter failures became epidemic and woofers began to come apart at the compliance rings and voice coils began to tear loose from cones.]" Another misnomer that I found was that PWK often referred to “acoustic watts” and invariably magazine writers (e.g., Robert Hartley), among others would drop the “acoustic” and just state watts, which was misleading and only perpetuated inaccuracies. The following are PWK definitions published in the "Dope From Hope" (Vo. 9, No. 2 June 1973) article titled "Definitions." WATT First of all a watt is a unit of power or rate of doing work, whether electrical, mechanical, thermal or acoustic. Equivalents are 0.738 foot pounds per second, 0.238 calories per second, or w = e^2/z Where w is watt, e^2 is electrical pressure or electromotive force in volts and z is electrical impedance in ohms. The acoustic watt may be similarly expressed in terms of acoustic sound pressure p in dynes per square centimeter and the acoustic impedance of air which has been derived as the product of the air density times the velocity of sound p thus w = p^2/z. When the sound pressure level is 100 dB, the sound power transmitted is 10^6 watt per square centimeter. (The 100 dB level is referred to zero dB = 0.000204 dynes per square centimeter: thus 100 dB = 20.4 dynes per square centimeter). ACOUSTIC WATT Translating the above numbers into something quickly useful, it turns out that a sound source radiating from a trihedral corner with a uniform polar pattern will be radiating one watt of power when the sound pressure measured at 4 feet is 118 decibels. Essentially, it came down to PWK’s literature recommending 20 watt amplifiers as the minimum for Klipschorn loudspeakers to meet his Klipschorn design goal of producing concert-level sound of 115dB SPL at the listener position. In my reference to Robert Hartley, I’m referring to excerpts from his book titled, "the Complete Guide to High-End Audio" where the excerpt can also be found in the article "How Much Amplifier Power Do You Need" where he writes that “loudspeaker pioneer Paul Klipsch conducted a demonstration of live vs. reproduced sound with a symphony orchestra and his Klipschorn loudspeakers. His amplifier power: 5W. The Klipschorns are so sensitive (an astounding 105dB SPL, 1W/1m) that they will produce very high volumes with very little amplifier power. Klipsch was attempting to show that his loudspeakers could closely mimic the tonal quality and loudness of a full symphony orchestra.” If anyone has been following the various posts in the “high power amplifier” thread, I would have a hard time believing that someone could still conclude that a 5 watt amplifier would attain that type of concert level SPL in a theater where a symphony orchestra was playing. The reference indicates that PWK talks about a symphony orchestra and 5 watts; however, he is not talking about a nominal 5 watts. I believe that PWK is actually talking about 5 "acoustic watts" as he has defined an acoustic watt in the Dope From Hope that I have excerpted above. Note that PWK has also put into print, including references in the Dope From Hope, a 20 watt per channel amplifier is suggested for full live symphonic dynamics (e.g., 115 dB at the listening position). To achieve the 5 acoustic watts in the room that PWK is talking about, he had two Klipschorns and a Belle with each channel connected to 20 watt amplifiers. Once I crunched the math considering the definitions in the "Dope From Hope" (Vo. 9, No. 2 June 1973) for an acoustic watt, it became pretty obvious what happened in that I suspect that Hartley may not have understood the concept of an acoustic watt or just dropped the word "acoustic" in his text. Essentially, there you have it in that it seems that PWK has outlined various situations that appear to indicate that for 2-channel stereo, 20 peak watts per channel or 10 watts average sine wave power would cover the concert level SPL THAT he had personally strived to achieve.

In full disclosure I am looking for the best sound possible. The means to get there is unknown to me at this time. Maybe I have arrived. AS you know I had a P/P 25 watt EL84 mono block set up. It sound a smidgen better than the yammy 1030... but only on a very few songs. 3 days and 3 sets of ears could not tell one from the other. 1. I have no idea who else sells tubes or SS that I could try other than the Pass30.8. Six moons review of that amp simply said ( in my words here) the 30.8 is over the top good. And that was against mega buck tube and SS Power AMPS. Like the review I linked to above, and my electronics background, prove that listening at 1 watt you need at least 20 more to pull from during dynamic passes. I am not up to building anything. Mike Sanders of QS fame and Nelson Pass are far more accomplished than I in that realm. There is nothing wrong with having a 30 watt SS amp playing at one 1 watt. With out question some music will dig into the 25 watt mark. That is the reason for that pass 30.8 At Best buy they have $50,000 worth of Mac amp preamp etc playing into $15,000 martin logans. Horrible compared to my khorns. When my K horns were puiing 1 watt the ML's were pulling 75. Point is the 30.8 power wise is certainly not to much power. If I never use the last 5 or so watts, all the better. The more power you pull from any amp, the more distortion it makes. I love my horns because they address the issue of efficiency. The Folded Bass is a wonder of the universe. ( there may be others, but they will cost way WAY more than what I paid for these 20+ yr old Khorns. I do not want or need to spend ~4 Large on a used 30.8. But if the sound is way better, then that is good. Same thing goes for tubes. I would try A&S casablancas but once you buy they are yours. NOT going to happen for me. I would posit to say, your definition of the sound you are looking for is not specific enough. "I am looking for the best sound possible” is a purely subjective call and if you interview 15 people and ask them to specifically describe “best sound” and what it means to them, you will probably get 15 very different answers. For example, some people look specifically to measurements as an “objective” tool to help them determine “accuracy,” which may be an important aspect of their “best sound.” However, “accurate” to what benchmark? Are we looking for accuracy when compared to the original studio session, accuracy in relation to the engineer’s mix, accuracy in reproducing “compression,” accurate in reproducing the tone or timbre of certain instruments, or accurate in that a Fender Stratocaster doesn’t sound like a poorly tuned banjo, or something else? Also, if audio gear is “too accurate” it will reveal every flaw in the recording itself and every flaw in the audio gear chain. Given “human nature” being what it is, people then tend to jump to unfounded conclusions that it must be the “amplifier” or the “speaker” (in general, people have been notorious for blaming the Klipsch speaker for poor recordings and poor choices in audio gear), which in turn, tends to impact the sales levels of the item. Others would claim that more bass, more punch, and more excitement from playing music is the “best sound.” Given the state of over-compression in music, the most accurate gear is not necessarily the best in playing heavily processed rock music and expecting more bass and more punch. Think of it this way, sometimes, a person just can’t make a cartoon look real by using a high resolution television. Some claim that a nice crisp high frequency is what they look for as being instrumental in the best sound, while others believe that the crisp high frequency makes for an etched and mechanical listening experience. In general, I believe that most manufacturers (especially those making mass-produced products) will go to extraordinary lengths to “claim” accuracy, to give consumers some level of “assurance” they are buying products that are accurate since the general consumer wouldn’t want their friends questioning them on why they bought an “inaccurate” stereo system (whatever that actually means). Personally, I’ve put together various systems to meet different listening objectives. For example, I’ve tailored a system for the bedroom that will create a surreal, lush and romantic tonal experience for my girlfriend rather than have an “accurate” system playing poor recordings, piercing her ear drums to the point where she has a headache and killing the mood. Another system involves my Klipschorns and is designed around a very detailed and highly resolving system of very minor details that are captured in good recordings where the criteria of very low noise and very low distortion levels using equipment with very linear circuits that need either none, or very little negative feedback. This system is my "evolution" system for experimentation where I swap various tube and solid state based components in an out of this system. My Jubilees are in another fairly resolving system that will probably also end up doing home theater duties, in addition to the two channel listening when I move to a bigger space. These are extremes on the continuum for me, but I have also put together other more general systems that fall somewhere in the middle of my continuum for general listening, general entertaining and occasional parties.

You attributed lack of bass to the difference in speakers not the difference in amps correct? I have a Stereo 15 amp from Justin on a pair of Cornscallas and there is absolutely no lack of bass there. lack of bass ( base) ( bass looks funny... like the bass fish...) is because LaScalas low freq cut off is around ~ 40 hz and starts at~ 50. This is because they were purposed for loudspeakers more than to be used as a means to play High Fidelity music. They sound good, don't misunderstand. BUT... When compared to Khorns.... well they don't compare in the realm of HiFi music reproduction. Your Cornscallas will certainly have better base than LaScalas. The folded horn of the Khorn takes BASS to the next level. Have you listened to Khorns set up with good equipment ? When I did, I could not believe my ears. Far better than the Snells of old. SNELLS were reference quality used to determine if this violin or that piano was up to speed. They were used for chamber music reproduction. That is not easy to do. Actually, the OP has already had a single-ended amplifier (the Big Ben is based off the Shannon Parks Clementine single-ended circuit and modified for the 6L6 or KT88 series of tubes) in his system; however, from the posts above, it seems to have some trouble driving the bass below the horn cut-off on the La Scala, which I would expect once transitioning to the frequency range below the horn cut-off, but appears to be fine in the Klipschorns. Part of what I see as problematic (and potentially leading to what appears to be frustration for the OP and others posting) with this thread is that the thread started out as a type of general critique of Rod Elliott's white papers on tubes and solid state then evolved into a tube amplifier hunt with no specific criteria or objective in mind. For example, what makes this a very difficult situation is that I cannot find where there has been any identification of the specific negative characters of sound that the OP doesn't like with the Yamaha 1030. In many respects this is like going to the doctor and just stating "Doc, I don't feel well today, treat me." Without a specific understanding of what is currently viewed as wrong (or lacking or could be improved upon) with the sound with the Yamaha 1030, it is impossible to diagnose and make any type of recommendation that would even be remotely useful. The aspect of having no specific goal is why I haven't directly responded to anything and only provided a few posts on various types of amplifiers and topologies where I had some direct experience. It seems that every time the kids come to me for advice, I end up asking them, "what are you trying to specifically accomplish and how do you believe these steps will be important in getting you there"?

Nice. As you approach the golden years, it may turn into this.

The .707 RMS is factored in before arriving at the max power of an amplifier (at least it should be). So if they measured 171 watts then that is what your amplifier made. Many manufacturers under rated the max power of amplifiers so they can boast better distortion numbers at full rated power. I've read that Nakamichi PA-7 amplifiers that are rated at 200 watt RMS actually can put out 370 watts per channel, but have never measured them. Roger For how long? I would think a 50 millisecond peak might be possible at an even higher power out, whereas the un-flattened top of a steady tone sine wave power for 200 RMS would be about 283 watts (283 x .707 = 200 watts). In the oldest catalogs I've seen, a tube amp "peak power" is typically 2x (3 dB) the RMS power. Some modern "dynamic power" ratings are about 3 dB higher than RMS, but I've never seen the duration specified. The other question re: RMS is, "at what frequency?" Is it at 1KHz? Or 30 Hz (PWK's suggestion)? Or with band limited pink noise, 500Hz to 2KHz? Over the desired bandwidth (e.g. 20 Hz to 20K hz)? Someone a few years ago posted here that it is an error to talk about RMS power at all. I was actually looking into trying to find more detailed information regarding peaks and better substantiate an average time of a peak or even a range; however, I realized that it seems mostly impossible to get enough information to remotely establish any comparability or reliability in any of the published numbers. Here one "standard" definition of a "dynamic headroom" test that I considered in some of my responses in this thread along with gathering a few more insights into transformer and capacitor ratings used in power supplies, in addition to power calculations. I found the Myers Sound paper below meaningful. "The EIA RS-490 (former IHF A-202) amplifier test standard includes a "dynamic headroom" test employing a 20-mS tone-burst. In an informal survey of musical recordings, power bursts were found with durations from a few milliseconds up to several hundred milliseconds, with an apparent clustering in the 80-200-mS range. Since the practical value of an amplifier depends on its ability to reproduce musical dynamics, a more useful power rating would be obtained by amending the dynamic headroom test to employ a 200-millisecond (or similar) tone-burst." http://www.aes.org/e-lib/browse.cfm?elib=4898 Excerpt from Myers Sound. [in the engineering community, the accepted method of generating a rating of the audio power produced by an amplifier is to connect it to a known load, apply a continuous sine wave signal to its inputs, and monitor its output behavior into the load. This is important to keep in mind as we examine the definition and measurement of “power.” The definition of instantaneous electrical power is quite simple: P = EI, where P = instantaneous power in watts, E = potential difference in volts, and I = current in amperes. However, this definition is minimally useful to us in an audio application because audio sources are not instantaneous pulses, nor are audio loads purely resistive. A sine wave is the building block from which real-world audio signals are built, making it a more appropriate source signal for measurement of an audio system. For a sinusoidal voltage source, power, while still measured in watts, is defined as“average power.” RMS (root mean square) is a method of calculating the voltage and current to obtain the average power. For example, if we look at the sine wave voltage at the output terminals of a power amplifier, we will find the RMS voltage to be the peak voltage (Epeak) divided by the square root of 2. If we measure the RMS sine wave current from the amplifier, we will see that, similarly, it is the peak current (Ipeak) divided by the square root of 2. Multiplying the two, we get: (E peak /(sq root 2)) * (I peak /(sq root 2)) = (E peak * I peak)/2 which is the average power for a sine wave. When an amplifier is rated in RMS watts, this is a shorthand way of saying “average watts obtained by the RMS method.” If you use a signal other than a sine wave, you must use a meter reading ‘true’ RMS voltage to obtain the correct average power. So what about peak power? Peak power is a special case where Ppeak = Epeak * I peak. For a sine wave, this is always twice the average power. A major problem with using this rating, however, is that many power amplifiers cannot maintain peak power for more than a few milliseconds. The standard method of testing a power amplifier to see if the power supply can maintain continuous peak power is to connect all channels of the amplifier into load resistors, drive the amplifier’s input with a square wave and monitor the peak voltage at the outputs. Almost all power amplifiers will ‘sag’ in output power under this drive condition. Now, having a power amplifier produce twice the continuous sine wave power is hardly necessary for music reproduction, but sometimes music signals produce short-term square wave or large sine wave-like waveforms. So how long should a power amplifier be able to maintain reproduction of a square wave or sine wave at full amplitude?] http://www.meyersound.com/support/papers/amp_power.htm

Here is one of somebody behind the times.

We may be waiting for a while for a review and I'm thinking that I'll just add this one to my list of items that I'm still waiting for the AU1C review to be posted, along with the review of the VRD upgrade (wondering if he got the MagneQuest transformer upgrade). Without the reviews, it has been getting much more difficult to live vicariously through AU1C's purchases these days.

The following assumes your 2 watt amplifier has a maximum RMS output (unclipped, undistorted) of 2 watts. It also recognizes that with KHorns at 1 watt it is already LOUD: You are listening to a 2 watt amplifier at 1 watt average....then a 3 db peak comes along and your amplifier puts out 2 watts for the duration of the peak. And a 3 db increase of sound intensity has you say ( subjectively) 'Oh it got a little louder there for a second'. Now you are listening to a 2 watt amplifier at 1 watt average....then a 10 dB peak comes along and your amplifier attempts to put out 10 watts and clips the waveform. Your amplifier ran out of gas. You say something like 'well that sounded a little rough perhaps I better turn it down a bit'. To have 10 db of headroom above 1 watt you need a 10 watt amplifier. I do not understand where you get "so to get the extra 3 db for our 10 db swing", to get a 10 dB swing you need 10 dB. Please read post https://community.klipsch.com/index.php?/topic/163148-high-power-amplifiers-for-heritage-speakers/?p=2004025. When I first read the Dope/Hope article, I had to pause and ask myself "why a typical 3,000 cu ft listening room?" Then it came to me. Back when PWK was designing the khorn, the ceilings were much higher than today. Furthermore, a well respected peer, RH Bolt, came up with what could be considered the best listening room layout calculations in 1946. I believe the chart is talking about 2 speakers in mono. I believe that if you measured from the critical distance of 2.23' in a 20'x15'x10' room, that 1 watts into a pair of (.5 watts each) LaScalas would result in substantially higher than 104 db. Moving the mic further would reduce the measured db by inverse sq law based on the critical position measurement. I cited an audio blogger claiming 20db or higher gains from the CLP, but I don't know the calculations and other caveats for instance frequencies. What I think is that in order to see what PWK is talking about, we have to consider a 20x15x10 room. We have to calculate how .2 watts shared into a pair of 104db efficient speakers can yield 100db. I hope someone will dust off their slide rule and give that a go. I'm finding that there is a rational basis for most everything that PWK has written, but it seems to take a lot of searching and background reading to discern exactly what he was looking at. Although, I just happen to know where we can find a slide rule. .

It has been a good mental exercise and now I think I finally did a better job of outlining the math in the post below as to why the low power SET amplifiers can drive Klipschorn, La Scala and Belle speakers to reference-type levels simulating the live event for certain types of music without clipping the amplifier. All I can say is, "Klipsch Heritage – so much more than the sum of the parts." The following assumes your 2 watt amplifier has a maximum RMS output (unclipped, undistorted) of 2 watts. It also recognizes that with KHorns at 1 watt it is already LOUD: You are listening to a 2 watt amplifier at 1 watt average....then a 3 db peak comes along and your amplifier puts out 2 watts for the duration of the peak. And a 3 db increase of sound intensity has you say ( subjectively) 'Oh it got a little louder there for a second'. Now you are listening to a 2 watt amplifier at 1 watt average....then a 10 dB peak comes along and your amplifier attempts to put out 10 watts and clips the waveform. Your amplifier ran out of gas. You say something like 'well that sounded a little rough perhaps I better turn it down a bit'. To have 10 db of headroom above 1 watt you need a 10 watt amplifier. I do not understand where you get "so to get the extra 3 db for our 10 db swing", to get a 10 dB swing you need 10 dB. It's basically a trick question as I’m probably mixing terminology on you somewhat and looking more at the “dynamic range” of a piece of music (e.g., difference between the softest passage and the loudest) in the context of a type of “peak to average capability” of the “in room” amplifier and loudspeaker combination thinking about acoustic SPL output that can be measured with a simple Radio Shack SPL meter rather than something like an amplifier test of “dynamic headroom” regarding how many watts were generated or needed before clipping to cover a 10dB peak over RMS power output using an 80-200 millisecond (or similar) tone-burst. For example, while it may be slightly unrealistic, I’m assuming that the 104dB sensitivity of the Klipschorn before any room gain and one watt of amplifier power will give me 104dB of sound electrically; however, I will probably have 3dB of room gain for SPL output that I “hear” from placing the loudspeaker in a room where the corners, walls, ceiling, and floor of a room all reinforce the loudspeaker’s output. There would be an additional 3dB output that I “hear” that is due to having two Klipschorn loudspeakers in the room rather than one loudspeaker and I was careful to keep considering the odd aspect of “loudness” in relation to “decibels” where one loudspeaker is producing a level of 104dB SPL at one watt of power, adding a second loudspeaker playing at the same level using one watt of power only increases the overall “loudness” by 3dB SPL (e.g., loudness does not double with two loudspeakers). Essentially, the two Klipschorn loudspeakers in stereo produce a “loudness” level of 107dB SPL in the room with each being driven by one watt amplifiers. Of course, I realize that I have technically doubled my power from one watt by now using a total of two watts for the two loudspeakers combined. Now rather than a 10dB tone-burst, I want to produce a “realistic” peak sound level for some type of music that I’m familiar with. For example, let’s say that I’m picking from a solo grand piano playing crescendos that can reach peak levels of 109dB SPL, I believe that a full orchestra in a concert hall measures peak levels of about 106dB SPL, and a rock group may have peak levels around 120dB SPL. Of course, I fully realize that my Klipschorn loudspeakers with a 2 watt per channel stereo amplifier, even factoring in the “room gain” doesn’t stand a snowball’s chance on a hot day in San Antonio of surviving realistic peaks of a rock concert and that is why I have other amplifiers. However, it seems that I should be fine with the 106 dB peaks in relation to a full orchestra in a concert hall electrically and acoustically; and maybe I can experience the feeling of 109dB peak level of the grand piano crescendo with my Klipschorn loudspeakers and 2 watt per channel SET amplifier. I fully realize that my 2 watt per channel amplifier will only electrically drive the Klipschorn loudspeakers to 107dB (104dB plus 3dB for doubling the power from one watt per channel to two watts per channel) and most likely any attempt above the 107dB will result in clipping assuming that my amplifier does not have any “head room” of power to handle a very short 20 or 30 millisecond burst of 2dB in excess of the rated power; however, that 107dB should still give me the “perceived” loudness of the 109dB I wanted to experience in the room given the aspects of room gain that I have outlined above. Circuit Overview The PA-7 delivers 200 watts per channel, uses no overall negative feedback (a Pass trademark), and boasts the Stasis section, which consists of a low-power voltage amplifier coupled to the current mirror bootstrap output stage to do all the heavy lifting required for high-power output. Back in 1989, when Stereo Review featured the PA-7, writer Julian Hirsch measured the PA-7’s output at 253 watts into an 8-ohm load, 400 watts into a 4-ohm load, and 650 watts into two ohms. A quick look under the hood reveals why. A large 700 VA toroidal transformer and a bank of power supply capacitors totaling 132,000 µf proves the PA-7 means business. Such a setup made the PA-7 a perfect choice for demanding loudspeakers and, like the Threshold Stasis amplifiers, it ended up in many systems based around electrostatic speakers or Magnepans. . Nelson Pass at his best. Nelson Pass sure has developed a nice legacy of amplifiers over the years and it doesn't matter whether we are talking about flea-watt power or gigantic brute force power, he certainly has done it all. One of my early experiences was with using his white paper from 1981 for the mosfet modification to the old Harman Kardon Citation 12 amplifier and I was hooked. I liked it so much that I also have a second mosfet modified Citation 12 that now has a complete restoration internally and cosmetically. In addition, it sure seems like the Sony VFET part 2 project is coming close to fruition. .

The .707 RMS is factored in before arriving at the max power of an amplifier (at least it should be). So if they measured 171 watts then that is what your amplifier made. Many manufacturers under rated the max power of amplifiers so they can boast better distortion numbers at full rated power. I've read that Nakamichi PA-7 amplifiers that are rated at 200 watt RMS actually can put out 370 watts per channel, but have never measured them. Roger The Nakamichi sure has turned into one of the classics that seems to have no problems with a 2 ohm load. The following is from Tone Audio Publications. Circuit Overview The PA-7 delivers 200 watts per channel, uses no overall negative feedback (a Pass trademark), and boasts the Stasis section, which consists of a low-power voltage amplifier coupled to the current mirror bootstrap output stage to do all the heavy lifting required for high-power output. Back in 1989, when Stereo Review featured the PA-7, writer Julian Hirsch measured the PA-7’s output at 253 watts into an 8-ohm load, 400 watts into a 4-ohm load, and 650 watts into two ohms. A quick look under the hood reveals why. A large 700 VA toroidal transformer and a bank of power supply capacitors totaling 132,000 µf proves the PA-7 means business. Such a setup made the PA-7 a perfect choice for demanding loudspeakers and, like the Threshold Stasis amplifiers, it ended up in many systems based around electrostatic speakers or Magnepans. .

I don't know the impact of horn loading on the woofer and I suspect it may be somewhat different for the Klipschorn vs the La Scala where a chunk of the La Scala frequency response is direct radiator vs horn loading, but I seem to remember that somewhere I had seen posted that 1W is ~ 97.7 dB SPL and 2.83V is ~ 101.7 dB SPL for the woofer. Although, I don't know if it was in reference to the pre 1984 version with the lower fs or the post version with the higher fs.

The following assumes your 2 watt amplifier has a maximum RMS output (unclipped, undistorted) of 2 watts. It also recognizes that with KHorns at 1 watt it is already LOUD: You are listening to a 2 watt amplifier at 1 watt average....then a 3 db peak comes along and your amplifier puts out 2 watts for the duration of the peak. And a 3 db increase of sound intensity has you say ( subjectively) 'Oh it got a little louder there for a second'. Now you are listening to a 2 watt amplifier at 1 watt average....then a 10 dB peak comes along and your amplifier attempts to put out 10 watts and clips the waveform. Your amplifier ran out of gas. You say something like 'well that sounded a little rough perhaps I better turn it down a bit'. To have 10 db of headroom above 1 watt you need a 10 watt amplifier. I do not understand where you get "so to get the extra 3 db for our 10 db swing", to get a 10 dB swing you need 10 dB. It's basically a trick question as I’m probably mixing terminology on you somewhat and looking more at the “dynamic range” of a piece of music (e.g., difference between the softest passage and the loudest) in the context of a type of “peak to average capability” of the “in room” amplifier and loudspeaker combination thinking about acoustic SPL output that can be measured with a simple Radio Shack SPL meter rather than something like an amplifier test of “dynamic headroom” regarding how many watts were generated or needed before clipping to cover a 10dB peak over RMS power output using an 80-200 millisecond (or similar) tone-burst. For example, while it may be slightly unrealistic, I’m assuming that the 104dB sensitivity of the Klipschorn before any room gain and one watt of amplifier power will give me 104dB of sound electrically; however, I will probably have 3dB of room gain for SPL output that I “hear” from placing the loudspeaker in a room where the corners, walls, ceiling, and floor of a room all reinforce the loudspeaker’s output. There would be an additional 3dB output that I “hear” that is due to having two Klipschorn loudspeakers in the room rather than one loudspeaker and I was careful to keep considering the odd aspect of “loudness” in relation to “decibels” where one loudspeaker is producing a level of 104dB SPL at one watt of power, adding a second loudspeaker playing at the same level using one watt of power only increases the overall “loudness” by 3dB SPL (e.g., loudness does not double with two loudspeakers). Essentially, the two Klipschorn loudspeakers in stereo produce a “loudness” level of 107dB SPL in the room with each being driven by one watt amplifiers. Of course, I realize that I have technically doubled my power from one watt by now using a total of two watts for the two loudspeakers combined. Now rather than a 10dB tone-burst, I want to produce a “realistic” peak sound level for some type of music that I’m familiar with. For example, let’s say that I’m picking from a solo grand piano playing crescendos that can reach peak levels of 109dB SPL, I believe that a full orchestra in a concert hall measures peak levels of about 106dB SPL, and a rock group may have peak levels around 120dB SPL. Of course, I fully realize that my Klipschorn loudspeakers with a 2 watt per channel stereo amplifier, even factoring in the “room gain” doesn’t stand a snowball’s chance on a hot day in San Antonio of surviving realistic peaks of a rock concert and that is why I have other amplifiers. However, it seems that I should be fine with the 106 dB peaks in relation to a full orchestra in a concert hall electrically and acoustically; and maybe I can experience the feeling of 109dB peak level of the grand piano crescendo with my Klipschorn loudspeakers and 2 watt per channel SET amplifier. I fully realize that my 2 watt per channel amplifier will only electrically drive the Klipschorn loudspeakers to 107dB (104dB plus 3dB for doubling the power from one watt per channel to two watts per channel) and most likely any attempt above the 107dB will result in clipping assuming that my amplifier does not have any “head room” of power to handle a very short 20 or 30 millisecond burst of 2dB in excess of the rated power; however, that 107dB should still give me the “perceived” loudness of the 109dB I wanted to experience in the room given the aspects of room gain that I have outlined above.