Chris A Posted February 20, 2012 Share Posted February 20, 2012 I've never encountered output impedances that high! You might check all the amps that you've associated with. You will likely be surprised if you haven't actually tracked the actual specifications. I was actually shocked by the SETs that I've looked at. It brings to mind a review of the Cary 300B which Stereophile ran http://www.stereophile.com/content/cary-audio-design-cad-300sei-integrated-amplifier-measurements"if it sounds good to you, it is good!"This is a "rubber yardstick" as PWK coined the term, and I'm a little bothered by it as being a bit cavalier...Chris [] Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted February 20, 2012 Share Posted February 20, 2012 "if it sounds good to you, it is good!" This is a "rubber yardstick" as PWK coined the term, and I'm a little bothered by it as being a bit cavalier... Chris The "rubber yardstick" term has also been debated since before I became involved. It brings to mind many blind listening tests in which I participated where solid state amps with vanishingly low distortion were auditioned against tube amps with more dubious distortion figures. What would be your conclusion when the listeners kept choosing the higher distortion tube amps as having the best sound? Why do so many solid state amps, including many with superb measured performance, sound like crap? As far as triode amps having rotten distortion figures, take a look at some of the budget output transformer measurements done by Tubelab some years back when driven by a 300B: http://www.tubelab.com/BudgetOPT.htm Makes you wonder what all the fuss is about. Regrettably, I no longer have my journal in which I had recorded the data for many of the designs I implemented over the years (thanks to Hurricane Floyd attacking my normally dry basement!), or I could present definitive data on many of the single ended designs that I've utilized. In any event, these questions will be debated indefinitely imho and unless someone comes up with a way to quantify exactly what the brain is doing when processing auditory information, there will be no answer. Maynard Quote Link to comment Share on other sites More sharing options...
Don Richard Posted February 21, 2012 Share Posted February 21, 2012 quote user="tube fanatic"]It brings to mind a review of the Cary 300B which Stereophile ran At the end of the measurements section well known audio pimp Robert Harley wrote the following. Talk about damage control and sucking up. The editors must have really been worried about losing Cary's advertising dollars. "A joke? I could be kind and use the phrase "less than ideal" to describe the 300SEI's technical performance. But I'll tell it like it is: this amplifier measures so poorly it's a joke. The large (more than 4dB) frequency-response aberrations when driving a reactive load, ridiculously high output impedance (more than 4 ohms), ultrahigh distortion levels, and severely limited output power are all contrary to what we consider good technical performance. I can easily imagine the non-listening audio-engineering community looking at these measurement results and laughing at audiophiles who must "like the sound of distortion." But after close critical scrutiny—both in the listening room and the test lab—I'm convinced that the 300SEI doesn't harm the signal in some of the ways push-pull amplifiers do, and that what the 300SEI does right is beyond the ability of today's traditional measurements to quantify. Further, I didn't enjoy the 300SEI so much musically merely because it introduced frequency-response deviations and added lots of low-order harmonic distortion. Instead, the 300SEI's fundamental musical rightness overcame its limitations".—Robert Harley Quote Link to comment Share on other sites More sharing options...
Chris A Posted February 21, 2012 Share Posted February 21, 2012 At the end of the measurements section well known audio pimp Robert Harley wrote the following...At some point, I believe that engineers will simply say [bs], and walk out of the room, no matter what the PC answer is.My observation: If you want soft clipping, buy a SET (personally, I don't want clipping at all, and I don't have to put up with clipping). If you like listening to even-order harmonics that aren't in the source material, you can buy a synthesizer that does that (such as an Aphex Aural Exciter), or you can buy a SET. If you want a reverb unit, you can buy a reverb unit, or you can buy a high-output-impedance SET. If you want EQ, you can buy an active digital crossover, or an EQ unit, or if you like the "canned EQ" that a SET brings (i.e., high and low end roll-off), you can buy a SET. If you want all of these "features" at once, then buy a SET: it might be cheaper (...or it might not be...). It also glows in the dark, heats the room, and gives you something to do (rolling tubes) when you are looking for something to do with your spare time... ...but please don't call it "high fidelity", because it isn't...it's a sound synthesizer/processor that has a small amount of forward loop gain. [] Chris Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted February 21, 2012 Share Posted February 21, 2012 At the end of the measurements section well known audio pimp Robert Harley wrote the following...At some point, I believe that engineers will simply say , and walk out of the room, no matter what the PC answer is.My observation: If you want soft clipping, buy a SET (personally, I don't want clipping at all, and I don't have to put up with clipping). If you like listening to even-order harmonics that aren't in the source material, you can buy a synthesizer that does that (such as an Aphex Aural Exciter), or you can buy a SET. If you want a reverb unit, you can buy a reverb unit, or you can buy a high-output-impedance SET. If you want EQ, you can buy an active digital crossover, or an EQ unit, or if you like the "canned EQ" that a SET brings (i.e., high and low end roll-off), you can buy a SET. If you want all of these "features" at once, then buy a SET: it might be cheaper (...or it might not be...). It also glows in the dark, heats the room, and gives you something to do (rolling tubes) when you are looking for something to do with your spare time... ...but please don't call it "high fidelity", because it isn't...it's a sound synthesizer/processor that has a small amount of forward loop gain. Chris Wow Chris, you sure don't like SETs!!!!! What's your take on people who use vintage integrated amps and make very definite use of the tone controls to create the sound that they want (like severely rolling off the top end to make modern recordings listenable through their K-horns)? I don't see that there's much difference. And as far as the distortion of SETs, did you look at the measurements that George came up with on those budget transformers (http://www.tubelab.com/BudgetOPT.htm)? That's more in line with my experience and certainly not anywhere in the range of being unacceptable imo. Cheers-- Maynard Quote Link to comment Share on other sites More sharing options...
Chris A Posted February 21, 2012 Share Posted February 21, 2012 Wow Chris, you sure don't like SETs!!!!! I'm not sure that you read my experience with Bottlehead 300B Paramounts - I couldn't imagine a SS amp sounding that bad, even if it was being driven by an iPod...it was unspeakably bad. And yes - I judge like amplifier designs by that singular experience. I have formed opinions on why people like SETs. I'll emphasize the positives below (since my mother raised me to be a nice person []): I like class A amplification with its very low crossover distortion. I like high slew rate amplifiers. I like extremely low distortion - THD, IMD (SETS typically do not have this, but Nelson Pass's First Watt F3 amplifier actually does). And I like low output impedance (...ditto on the First Watt F3). The First Watt F3 delivers on all counts, with somewhat marginal output impedance (1 Ohm), but my TAD TD-4002s have a minimum input impedance of ~11 Ohms (and ~27 Ohms max) when connected to K-402 horns, so the F3 is more than 10x lower output impedance than the load it is driving. If you are using Khorns, note that the minimum impedance has been measured as 3.2 Ohms by Richard Heyser in his now-famous Khorn review (the impedance plot is reproduced below), and has low input impedance in two areas: 45-400 Hz, and 5-10 KHz, both areas that fenderbender mentioned above as problem areas using the First Watt F3. My knee-jerk solution to fenderbender's F3-Khorn problem would be to replace the Khorn passive crossovers with an active digital crossover (like Greg Oshana documented elsewhere on this forum), then the impedance matching problems would be non-issues. I now understand fenderbender's issues a bit more when looking at the complex impedance plot of the Khorn, but note that a simple EQing down of these two FR bands would probably achieve at least 50% of the desired effect, that is, you would still need to correct for time misalignment of the drivers to get truly outstanding imaging and impulse response. But the F3 isn't responsible for the problem as you can see - it surfaces the problem in the Khorn crossover design. Chris Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted February 21, 2012 Share Posted February 21, 2012 I have the greatest respect for the works and thinking of Richard Heyser..! I suggest to anyone interested in audio reproduction reading this gathering of his works if you want a better understanding of the reality of what we are doing and the challenges: "Time Delay Spectrometry" an Anthology published by the Audio Engineering Society Here are a reminder of some of his Very Wise Thoughts that I ran across again. "The evaluation of the acoustics of loudspeakers and the room containing them proved to represent a microcosm of all the difficult problems in wave propagation." "Nature does not solve equations." "The thing we call time in audio measurements and the things we call frequency are different coordinates for describing precisely the same signal." "Pitch is not frequency." "At the present state of sound reproduction technology, the audio engineer shares the professional goal of a magician." "The effect that modern sound reproduction strives to achieve is the creation of an acceptable illusion in the mind of the listener." "If we wish to understand how to 'measure' what we 'hear,' then we must deal with subjective perception and the illusion of sound." "The actual sound field in a listening environment is not identical to the sound field which we may perceive..." "The end product is the listening experience." "One of the worst-kept secrets in audio engineering is that what we hear does not always correlate with what we measure." "Those whose principal professional involvement is based on the listening experience tend to develop a subjective viewpoint with value judgments seldom related to instrumental measurement." "One of the most belittling experiences is to deride the 'black art' of a craftsman who gets consistent results by a certain ritual which he cannot explain and then to discover that his actions in fact held a deeper technical significance than we understood at that time from our simplified model." "If we measure the frequency response of a system, and do it correctly, then we know everything about the response of that system. We have all the technical information needed to describe how that system will 'sound.' But the information we have is not in a system of coordinates that will be recognizable by a subjectively oriented listener...That is the root cause of the continuing fight between subjective and objective audio. It is not that either is more correct than the other...rather it is due to the fact they do not speak the same language." "The next time you hear an argument between a technologist and golden ear about the audibility of certain types of distortion...is it possible they do not agree because each have [sic] a view through a different window?" "You out there, Golden Ears, the person who couldn't care less about present technical measurements but thinks of sound as a holistic experience. You're right, you know." miketn Quote Link to comment Share on other sites More sharing options...
mike stehr Posted February 21, 2012 Share Posted February 21, 2012 . Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted February 21, 2012 Share Posted February 21, 2012 Chris why have you changed your solid state amplifiers weren't the specs good enough..? Aren't the specs of the Pass F3 inferior to the crowns you were using.? To judge any type of amplification from one example or one set of criteria and then set about to bash all of them is not wise IMHO..! What's your end goal Chris the perfect measuring system(and what would those measurements be?) or the best illusion possible in your listening room..? mike tn Einstein: "Not everything that can be counted counts, and not everything that counts can be counted" Quote Link to comment Share on other sites More sharing options...
Chris A Posted February 22, 2012 Share Posted February 22, 2012 Aren't the specs of the Pass F3 inferior to the crowns you were using.?No. actually they're not...slew rate is much higher, and power supply voltage regulation is probably better for the range of output that the amp is being used (based on weight of power supply alone); zero crossing error is reduced due to pure class A construction. THD is a little higher but still at or below audible threshold (0.1% into 16 Ohms vs. 0.001% into an unspecified load, but the F3's THD is much lower than stated at less than 1 Watt output: .01%), noise floor is about the same as the D-75As (100 uV unweighted noise floor vs. 106 dB SNR at full power - you can do the math, my ears tell me its about the same quiescently). Output impedance is not as good (1 Ohm vs. 0.015 Ohm) due to the F3's use of a single-stage amplifier design that has less available forward-loop gain than the D-75A design and therefore less negative feedback capability to drive its output impedance down: this is good a design tradeoff, IMHO. The F3's single stage design's effect on signal fidelity is much better than the multi-stage D-75A. Reliability is much better due to reduced part count, very long service life of the parts, and negligible drift of part performance vs. time vs. the D-75As. Signal bandwidth is 75 Khz vs. 20 Khz. Warm-up time is about the same, surprisingly (about 1 minute to reach 90% of fully warmed-up performance). To judge any type of amplification from one example or one set of criteria and then set about to bash all of them is not wise IMHO..!I've heard enough to form an opinion vis-a-vis SETs...sorry, Mike. I try to be pleasant when the subject is brought up. I don't like tube gear for the reasons we have discussed at length before, some of which is highlighted by the performance factors that I listed above, not the least of which is reliability measured in MTBF. I know that I'm not alone in my opinions but others are hesitant to voice those opinions since they run into strong decision bias (i.e., "if it tests bad tests bad, it must sound good") from the tube crowd; I don't subscribe. But you already know all this from our preceding discussions. [] What's your end goal Chris? The perfect measuring system (and what would those measurements be)? Or the best illusion possible in your listening room?I don't believe that I have a "perfect measuring system". Are you proposing one? I didn't think that I implied that I had one. There are factors that I look at, some of which I've listed above, one that I haven't: listening test. Slew rate is another big one: higher slew rate amps sound much better to my ears, especially when reproducing strings (violins) and cymbals; this is the real difference that I believe I hear from the F3 vs. the D-75A. I strive for accurate reproduction in the same vein as PWK did, which I'm apparently finding is increasingly controversial among forum members. I'm actually not looking for illusions, but rather accuracy in reproducing what is on the source material--which may come as a shock to "if it sounds good...it is good" subscribers. I don't try to fix objectionable recordings but rather present them as they have been recorded, without tweaking them individually. My musical tastes are broad enough to keep searching for recordings that sound good. I keep some recordings that are poorly made but that represent a relevant historical record for my needs, but as a rule, I don't listen to those often. When I do find recordings that sound poor, I sometimes tinker with my system to see if it could be caused by or exacerbated by my setup. I've made a many improvements to my system over time using this approach. I'm presently very satisfied with what I've got, but I might tinker a bit if I get a recording that sounds poor, just to make sure that it isn't my setup. I've actually learned quite a lot using this approach. And I've found that I've drifted toward a more neutral setup in doing this. Chris Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted February 23, 2012 Share Posted February 23, 2012 I don't like tube gear for the reasons we have discussed at length before, some of which is highlighted by the performance factors that I listed above, not the least of which is reliability measured in MTBF. I know that I'm not alone in my opinions but others are hesitant to voice those opinions since they run into strong decision bias (i.e., "if it tests bad tests bad, it must sound good") from the tube crowd; I don't subscribe. But you already know all this from our preceding discussions. How do you think the "Tube Crowd" feel Chris when they can't voice their opinions without running into attitudes like this..! Maybe your decision bias is showing also..?[] Look Chris I believe I can hear just as well as you and I'm not stupid or self dillusional about the pro/cons of all types of amplification. I'm well aware about equipment reliability since I've spent a large part of my life in servicing electronic equipment and I can assure you that Tube Equipment can have an extremely long/reliable service life. I've built and modified Tube and SS equipment for close to 40 years and I can assure you that not everything that can be heard when modified is measureable with many of the standard measurements advertised or used by many dsigners. Since no peace of equipment I'm aware of is perfect and obviously we still have alot to learn in correlating measurements to the human experience then IMHO we must be on guard about trusting the measuring or listening experience but in the end it is about the human experience that this hobby/goal has been all about..! I strive for accurate reproduction in the same vein as PWK did, which I'm apparently finding is increasingly controversial among forum members. I'm actually not looking for illusions, but rather accuracy in reproducing what is on the source material--which may come as a shock to "if it sounds good...it is good" subscribers. I don't try to fix objectionable recordings but rather present them as they have been recorded, without tweaking them individually. My musical tastes are broad enough to keep searching for recordings that sound good. I keep some recordings that are poorly made but that represent a relevant historical record for my needs, but as a rule, I don't listen to those often. Chapters 1 and 2 of Floyd E. Toole's book gives much to think about when it comes to sound reproduction and should be must reading for anyone serious about this goal as well as Heyser's work I refered to in an earlier post. http://www.amazon.com/dp/0240520092/?tag=googhydr-20&hvadid=15186401035&ref=pd_sl_1hlnmin2b5_b http://www.aes.org/publications/anthologies/ Sinse I asked Chris his Goal to be fair I'll give my Goal: IMO while each part of the reproduction chain can/must have goals of accuracy for the job it has to do (as we come to understand and correlate measurements to perception) the ultimate goal is a perceptable illusion of real instruments, real human performers, set in a real acoustical stage/enviroment that evokes an emotional connection similar to what happens in reality. My system reflects my goals and while I have a relative accuracy by design I also must have the ability to compensate for many of the variables of the real world recordings I enjoy and I believe it can be well argued this might be the only way to hear the closest reproduction to true artist/engineer's intended performance. miketn P.S. I want to apologize to Rolly for having taken off topic in his thread as much as I have. Quote Link to comment Share on other sites More sharing options...
Chris A Posted February 23, 2012 Share Posted February 23, 2012 Quote How do you think the "Tube Crowd" feel Chris when they can't voice their opinions without running into attitudes like this..! Maybe your decision bias is showing also..? I freely admit my decision bias in this area. Sorry that it's different than yours, truly, I am. Quote Look Chris I believe I can hear just as well as you and I'm not stupid or self delusional about the pro/cons of all types of amplification. I never meant to imply that, and I apologize if I gave that impression. I didn't say that there aren't excellent tube amps out there. My issue is with the basic SET design as implemented by most manufacturers. Quote Since I asked Chris his Goal to be fair I'll give my Goal: IMO while each part of the reproduction chain can/must have goals of accuracy for the job it has to do (as we come to understand and correlate measurements to perception) the ultimate goal is a perceptible illusion of real instruments, real human performers, set in a real acoustical stage/environment that evokes an emotional connection similar to what happens in reality. That's okay...I would respectfully ask if you to could also acknowledge that my goals can be different than yours and still be valid...and still remain friends in the process. [] Life has got serious moments: I don't believe this is one of them--rather just dialogue. I also hope that this topic isn't too far from the OP's intent. Differentiating Pass FET amplifier designs from garden variety SET tube designs was the intent. And why FET amps are attractive and preferred in terms of balanced performance over SET designs. I believe that the goal of amplifiers is predominantly technical in nature, i.e., attainment of design performance parameters DOES apply. I also believe that it's a lot of work using engineering test gear and technical expertise/experience to achieve design goals than an art form in going about achieving "good sound". Picking the performance parameters that you want to maximize and others that you don't care so much about is supremely important in what you eventually end up with, in total, for your sound reproduction system. And those chosen performance parameters should map to what you value overall for the outcome. Cheers, Chris Quote Link to comment Share on other sites More sharing options...
Don Richard Posted February 23, 2012 Share Posted February 23, 2012 Picking the performance parameters that you want to maximize and others that you don't care so much about is supremely important in what you eventually end up with, in total, for your sound reproduction system. And those chosen performance parameters should map to what you value overall for the outcome. So true. Here is a device that costs about 1/3 the price of the Cary SET amp referenced earlier that can sweeten the sound of any system, and to the degree desired: http://www.empiricallabs.com/distdes.html Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted February 23, 2012 Share Posted February 23, 2012 https://passlabs.com/articles/single-ended-class-a "In the meantime, transformer coupled single-ended triode amplifiers are the alternative, using very large gapped-core transformers to avoid core saturation from the high DC current. These designs reflect more traditional thinking in single-ended amplification. They suffer the characteristic of a loosely coupled transformer, more limited wattage, and higher measured distortion than their solid state counterparts, however they still set the standard for midrange lucidity, and are not to be dismissed." "There has been a failure in the attempt to use specifications to characterize the subtleties of sonic performance. Amplifiers with similar measurements are not equal, and products with higher power, wider bandwidth, and lower distortion do not necessarily sound better. Historically, that amplifier offering the most power, or the lowest IM distortion, or the lowest THD, or the highest slew rate, or the lowest noise, has not become a classic or even been more than a modest success. For a long time there has been faith in the technical community that eventually some objective analysis would reconcile critical listener's subjective experience with laboratory measurement. Perhaps this will occur, but in the meantime, audiophiles largely reject bench specifications as an indicator of audio quality. This is appropriate. Appreciation of audio is a completely subjective human experience. We should no more let numbers define audio quality than we would let chemical analysis be the arbiter of fine wines. Measurements can provide a measure of insight, but are no substitute for human judgment." Wise words from a very experienced designer in this article..! Please read the complete article by Nelson Pass miketn Other articles by Pass: https://passlabs.com/articles Quote Link to comment Share on other sites More sharing options...
Marvel Posted February 23, 2012 Share Posted February 23, 2012 I'm not sure that you read my experience with Bottlehead 300B Paramounts - I couldn't imagine a SS amp sounding that bad, even if it was being driven by an iPod...it was unspeakably bad. Makes me want to hear a pair, so I can compare to my Moondogs. I couldn't be happier with my 2A3 amps. Considering the cost of them when they were made, I would guess the Welborne Labs amps are better to begin with.To be fair, I have constant impedance crossovers, which I am sure is a significant help. Bruce Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted February 23, 2012 Share Posted February 23, 2012 That's okay...I would respectfully ask if you to could also acknowledge that my goals can be different than yours and still be valid...and still remain friends in the process. Life has got serious moments: I don't believe this is one of them--rather just dialogue. I agree Chris...and everyone should set goals for our systems and what they want to acheive from them. I believe that the goal of amplifiers is predominantly technical in nature, i.e., attainment of design performance parameters DOES apply. I also believe that it's a lot of work using engineering test gear and technical expertise/experience to achieve design goals than an art form in going about achieving "good sound". Picking the performance parameters that you want to maximize and others that you don't care so much about is supremely important in what you eventually end up with, in total, for your sound reproduction system. And those chosen performance parameters should map to what you value overall for the outcome. It is without a doubt technical and art but the best designs and designers are aware of the art portion and it's this awareness that set's a higher standard of design. I still remember Roy while talking about designing loudspeakers saying something along these lines "many times I've been very proud of a curve I had acheived in a loudspeaker only to be disapointed when I listened to it". The final success of any design in audio/acoustics still has to be heard to know if it has been acheived. miketn Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted February 24, 2012 Share Posted February 24, 2012 https://passlabs.com/articles/single-ended-class-a Wise words from a very experienced designer in this article..! Please read the complete article by Nelson Pass miketn Other articles by Pass: https://passlabs.com/articles Great article which I'll show to some of my inveterate push-pull amp designer buddies with whom I constantly argue the virtues of single ended designs. I certainly agree with the statement, "As a result of its single-ended nature, the harmonic content of air is primarily 2nd order, and most of the distortion of a single tone is second harmonic. Air's distortion characteristic is monotonic, which is to say its distortion products decrease smoothly as the acoustic level decreases." Makes a great case for near field listening using a SET! Quote Link to comment Share on other sites More sharing options...
Chris A Posted February 24, 2012 Share Posted February 24, 2012 Quote Makes me want to hear a pair, so I can compare to my Moondogs. Bingo... I've not heard anyone else here that has listened to these and given a critical review that I can trust. Note that the mono-blocks that I have were assembled, tested, used briefly in a trade show demo, then packaged and shipped to me by Bottlehead themselves. All I did was plug them in and listen, basically. I even specifically asked "Doc" to personally guarantee that these two units were "good to go" and were within specifications (if they had any that they were standing behind...). None of that mattered, unfortunately, as I believe that their basic design is not good: YMMV. I keep these two mono-block amps as a reminder to myself to not repeat that mistake again. Betting on these tiny companies is not like betting on Klipsch, which I have done in the past in buying Jubs sight unseen/unheard and was highly successful. These "burned in" mono-blocks were not cheap: in fact they were more expensive than the used First Watt F3 FET amp that I picked up on A'goN. I'm thinking that there are a lot of garage-shop and slightly better tube electronics shops that honestly believe that they are fully set up to produce high quality, tested, and well-designed tube amps and preamps, etc., but they're really not even though they will tell you that they are. I really don't see any large manufacturing businesses dealing in tube electronics, such as the big multinational U.S. and Japanese firms, although I haven't been looking thoroughly at this market since my Bottlehead experience. The best that I've read about is the Silver Seven series from Bob Carver, but few can actually afford those exquisite units--even used--and they have a lot of power headroom that I don't think that I need to drive my 110 dB/W TAD drivers in a bi-amped configuration. Some of the issues that I've read about regarding the products from these type of mom-and-pop tube shops (and I apologize in advance if I step on anyone's toes here, because I know that I probably will...), is that their products are not being designed and tested using any kind on large-business standards or "regression test checks" with other commonly used interfacing hi-fi gear, and therefore only work under certain conditions, both upstream and downstream of the amp or preamp in question. Most of the product testing is occurring in beta, i.e., by paying customers, which is a really bad business model for hardware for the customers (but not the business owners), IMHO. And these tiny firms often do not stand behind their gear in terms of money-back guarantees if the customer is not satisfied. Note that First Watt/Reno Audio does have a money-back guarantee. So, you might get what you pay for with these tube designs, but you are actually taking more than a bit of a risk. I took the risk and lost. Worst than that, I've got people trying to tell me that I'm not "using them correctly". Please don't ever try to lay that kind of line on me: it's quite insulting. My gig is in the engineering of very complicated systems which are designed to do their job extremely well under all kinds of environmental and interfacing conditions. I've found that "art" can be involved in this process but when it is required, it's almost always necessary because the product was conceived poorly and the resulting manufacturing and customer use of the product has to be "art", rather than "plug-and-play" as the customer desires it to be. Product success in my business must be achieved in very low initial runs, and also that same product must be manufacturer and usable later in moderate production runs comparable to mainstream consumer electronics gear. These products also must work the first time that its built, tested, and used by the customer in rigorous tests and under challenging environmental conditions. [] Chris Quote Link to comment Share on other sites More sharing options...
Chris A Posted February 24, 2012 Share Posted February 24, 2012 Quote Great article which I'll show to some of my inveterate push-pull amp designer buddies with whom I constantly argue the virtues of single ended designs. I certainly agree with the statement, "As a result of its single-ended nature, the harmonic content of air is primarily 2nd order, and most of the distortion of a single tone is second harmonic. Air's distortion characteristic is monotonic, which is to say its distortion products decrease smoothly as the acoustic level decreases." Makes a great case for near field listening using a SET! I need to be clear: this is exactly the type of approach that I cannot accept (...with specific apologies to tube fanatic here...). You need to know as a consumer that you don't ever have to put up with that kind of poor quality, especially at the prices that these type of amps and preamps command. I don't want those harmonics AND I know that I don't have to put up with them plus other "features" of these type of designs that do not adhere to the definition of hi-fi: linear response that adds and subtracts nothing. AND the price that I will pay for better products is perhaps lower than these mom-and-pop shops are putting out. Sorry, but this isn't good business. I believe that the FET amp that I've mentioned is one example of a much better product. Sorry to be blunt but I've found that subtle responses apparently don't make it through. Chris Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted February 24, 2012 Share Posted February 24, 2012 Makes me want to hear a pair, so I can compare to my Moondogs.Bingo ...I'm thinking that there are a lot of garage-shop and slightly better tube electronics shops that honestly believe that they are fully set up to produce high quality, tested, and well-designed tube amps and preamps, etc., but they're really not even though they will tell you that they are. I really don't see any large manufacturing businesses dealing in tube electronics, such as the big multinational U.S. and Japanese firms, although I haven't been looking thoroughly at this market since my Bottlehead experience. The best that I've read about is the Silver Seven series from Bob Carver, but few can actually afford those exquisite units--even used--and they have a lot of power headroom that I don't think that I need to drive my 110 dB/W TAD drivers in a biamped configuration. Some of the issues that I've read about regarding the products from these type of mom-and-pop tube shops (and I apologize in advance if I step on anyone's toes here, because I know that I probably will...), is that their products are not being designed and tested using any kind on large-business standards or "regression test checks" with other commonly used interfacing hi-fi gear, and therefore only work under certain conditions, both upstream and downstream of the amp or preamp in question. Most of the product testing is occuring in beta, i.e., by paying customers, which is a really bad business model for hardware for the customers (but not the business owners), IMHO. And these tiny firms often do not stand behind their gear in terms of money-back guarantees if the customer is not satisfied. Note that First Watt/Reno Audio does have a money-back guarantee. So, you might get what you pay for with these tube designs, but you are actually taking more than a bit of a risk. I took the risk and lost. Worst than that, I've got people trying to tell me that I'm not "using them correctly". Please don't ever try to lay that kind of line on me: it's quite insulting. No offense taken to any of our discussions on this subject Chris. I thoroughly enjoy point/counterpoint conversations on almost any topic. In regard to the garage shop and mom/pop tube equipment builders, much depends on the individual business philosophy. Although not formally "in the business" at this point, I still do design/build amps and sundry other tube stuff for friends, friends of friends, etc. But, in almost all cases they get to hear the amps in their system before buying since I keep many prototypes of all kinds on hand for just that purpose. Using the prototype for say a week gives folks an ample opportunity to "try before you buy." When I build a clone of the prototype they have the assurance of knowing exactly how it will sound while getting to choose the kind of enclosure or chassis that they want and so on. Yes, on occasion someone finds some tubes at a garage sale or hamfest and asks me to build an amp around them; however it's with the understanding that they are taking a bit of a gamble since the exact sound won't be known until it's in their system. Usually, it works out fine. There are people all over the country who operate small, custom tube amp businesses whether they are for home audio systems or guitar enthusiasts. Many do terrific work and build to "battleship" standards. So, one really can't generalize. And, from what I've read, a perfect example of what I'm saying is the forum's own Craig! In the time I've been on here, no one has ever had anything but high praise for his amplifiers which some have apparently purchased without even hearing them. Regards-- Maynard Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.