Erik Mandaville

Hi, Well, Wal Mart was out of the Grippers last week when I looked. I went again this morning and they had some new stock in. So I picked up two packs, so I can add as needed. They look like they could be pretty effective and damping resonances, and are thicker than I expected them to be. I'll try 'em out soon and let you know. Hope you get some takers on your fine cabinet work. Would you be up for a commission sometime early next year? Thanks, have a good Sunday, Erik

Max: You might also ask your builder friend what sort of input filter he will use if he installs a tube rectifier -- two choices: Choke input filter (probably would cost a little more but better, I think) Capacitor input filter. The situtation here presents some power transformer issues that are a little different than a solid state circuit. In addition to the B+ (high voltages), there will also be the need for a secondary on the transformer to heat the rectifier tube. The only reason I bring this up, is that tube rectification is going to cost more than an SS bridge rectifer -- which can be bought here in the States at Radio Shack for almost nothing. I will reveal that, like Kelly, I prefer a tube rectifier on my amps. I just wanted to explain that the manner in which an amp's DC requirements are converted from AC to DC (either hollow or solid state)is not necessarily a reason to not buy a particular design. Listen to it at home and then decide. I believe a great deal of how we perceive music also depends on things that are not always associated with the electronic machines that reproduce it. The way we feel on a given day, mood, fatigue, high energy, etc., certainly must come into play, here as well. And this might ultimately influence not only what kind of music one might be in the mood to hear, but also the tone and quality (which is associated with the electronics)of the playback. In other words, there is a human element that comes into play, as well. anyway....this is getting sort of philosophical... Have a good day, Erik By the way, Max: It might not be the best idea to install a tubed phono stage within the amp, itself, if that's what you were intending. If your builder can build you a freestanding phono stage, ideally with a separate rather than integrated power supply (to reduce the potential for noise), that would good. But then the question remains! The phono stage will require DC voltages, so you have to decide on what sort of rectification would be best to employ. Erik

To All Who May Be Interested: With rare generosity from a fellow forum member (I'll keep his name with-held just in case it is preferred), I am in the process of comparing, side-by-side, both the AL and AA neworks in my 1 month old La Scalas. A school-related chore out of the way, I can take time to carefully listen to both. The La Scalas (vintage 1989) came with the AL networks, about which I have heard mixed impressions. Temporarily on loan are a well-cared-for pair of the comparatively more simple AAs, and only one is now installed and playing in the system. It doesn't usually take me long to notice differences in my system (even with my increasingly poor hearing from previous drumming days...), and such was the case with a first listen this afternoon. Immediate impressions in comparing the AA to AL are as follows: AA is less closed-in and constricted. There is an obvious increase in the sense of space and 'air,' and I find the overall presentation literally less filtered and more transparent. Intersong hiss is a bit brighter with the AA network, and easier to detect -- this subsequently results in greater retrieval of subtle detail(this is just my opinion, mind you...). I very much enjoy hearing certain indirectly related details important to the sense of realism -- fingers plucking steel and nylon guitar strings, over-tones of toms and snare on drums, the decay of hi-hat, ride and crash cymbals, breathing of players between phrasing, etc. -- and all of these have so far come through to me more with the AA networks. I hate to use the ubiquitous 'lifting of a veil' to illustrate the comparison, but that analogy works in this case. ...more to come by tomorrow. Erik

Absolutely right on, Kelly! What Mobile has outlined is both the point and enjoyment in serious audio and music listening -- and learning a little bit of DIY helps make the journey more personal and rewarding. He has hit the nail hard, right on the head, and one must agree (I do!) that there is no right or wrong where personal tastes, in either aesthitic issues or the voice preferences of an amplifier, capacitor, coil, resistor, transformer, etc., etc. So we are not trying to 'beat' one another, or 'win' or anything else remotely related to some sort of audio/electronics competition. This is what's refreshing and interesting about this forum. Most often, even if there are disagreements, arguments, articulate announcements (...that's a quote from a King Crimson album!), most know to back off a bit and let the air clear. It all makes for a dynamic exchange bewteen forum members. Have a listen to those amps if you can, and see what you think. Forget about what others present might say or believe, and let your ears be the judge. Perhaps ask if there might be a way to audition them in your own listening area -- skeptical about room effects years ago, I've learned that it can have a really significant impact on what music sounds like. I also have to do some work in that area, but I think my very significant other might not like what I come up with in a visual sense. Funny, Kelly (if you're listening here!), that you were also a drummer. What an *** (pardon my language) I was to sell my kit in order to buy a car for college transportation. I hate thinking about that, but dream of the day I might be able to afford a Roland V-Pro, maybe...something where I can have an acoustic stick feel, while being able to control the volume. Let us know what you think of those amplifiers! I tried to have a look at them via the link supplied, but I sat for too long a time waiting for something to happen, and gave up! Erik

Aesthetics is really a personal issue, and, just like the use of oil or poly caps, must be left to the preference of viewer/listener. So what doesn't 'get it' visually for one person, might be exactly what someone else is looking for. There are probably as many people who prefer solid state rectification over a more purest tube approach. Having used and incorporated both designs in pieces I have built from scratch, I will agree with Kelly that tube rectifiers can have a richer, perhaps more 'liquid' sort of quality. I've heard SS rectifiers being described as 'sterile' sounding, though to my ears that translates more into a kind of 'fast and detailed' presentation. Some amp designers who previously used tube rectifiers have changed over to solid state designs, and some combine a little bit of both -- tube rectification (such as 5Y3, 6X$, GZ 37/34 and others for the B+ voltages) and SS bridge rectifier circuits/filters for secondary filament supplies. Both get the job done, and again in the final analysis, there can't be one intrinsically better or worse than the other -- it's a personal choice. I have a preamp that I built from scratch, that was originally intended (as far as what is shown on the schematic) to be used with inexpensive diode rectfiers. Some use snubbers in the high voltage section to reduce noise, but I wanted to try full-wave tube rectification using a tube with appropriate specs. for the job. I also built this preamp using Radio Shack diodes, and have been able to compare them side-by-side. To me, the tube circuit is surely more relaxed and (only maybe) more natural in terms of how it compares to real, live music. The SS rectified version is decidedly 'jumpier' and sort of 'athletic' and quick -- which I happen to like. Both low and high frequency transient response seems to be sharper with the solid state approach, as well. There are some very, very successful designs where a solid state rectifier circuit is absolutely appropriate and effective. I would absolutely not abandon a tube amplifier designed with one if it performs well. I have recently been comparing a $300 amp to one that is many times that price (the former uses a convential SS diodes - the latter a 5Y3 with choke input filter), and can honestly say I believe I prefer the less expensive amp to the higher priced one -- as does my wife, who listens to music as much as I do. Music being an important part of my past (playing drums and percussion in a variety of bands -- rock, jazz, fusion, etc), the little $300 amp., to me, presents a more convincing illusion of the real thing. That simple. Have fun and Enjoy ....and Friendly Regards, Erik

Great! Thank you both for your help, Erik

Hey, Are the Klipschorn and La Scala tweeters/drivers one and the same? In otherwords, if a given tweeter fit the mounting position and holes on a klipschorn -- and in fact came from a klipschorn, would it fit exactly the same in a La Scala? Any thoughts or knowledge is appreciated! Thanks, Erik

Jazman: What I am essentially saying is that, if your sources are say within a few feet of your amplifiers, many people can obtain quite satisfactory sound without using a preamplifier. The couple of volts on the output of a CD player can easily drive the Moondogs without the need of active preamplification. I used to use the Moondogs this way (but with a passive linestage I built for volume and switching control), and things worked out very well. With my amplifiers now more than 20 feet from my sources, I need the extra gain provided by an active line stage -- CD straight into the amplifiers doesn't work for a number of reason, long ICs being the main problem. Without the extra drive capability of an active preamp, one suffers miserably from poor high frequency response imposed by the capacitance of a long run of interconnect. This is even a problem with certain high output impedence preamplifier circuits -- the high output impedence can't drive the capacitance of the cable. My preamp uses a direct-coupled, cathode follower topology, which has a very low output impedence. Thus, long runs of cable are not such a problem. Your system seems to be just fine, don't worry about it! If you want to put a volume control on your amps, it's easy to do, but I would use a 5K-10K resistor between the wiper of the volume control and the grid of the input tube. Erik

This topic still needs time to develop, but a quick switch of the secondaries on the Moondog OPTs enabled a more proper match for the La Scalas, and we spent an afternoon and evening listening to a variety of music. I had been using the La Scalas with my little ASUSA K2003 for the past couple of weeks, and I have been very surprised by the performance of this much less expensive amplifier. I built both the ASUSA and Moondogs from kits, and the ASUSA parts count and quality are rather different from the sort of quality Ron W. supplies with all of his kits. The ASUSA is a very 'quick' sounding amplifier with excellent high frequency extension (in my opinion), and has right now become the preference to use with the La Scalas. The Moondogs were 'darker' sounding, and didn't seem to have the polished, crystalline voice of the ASUSA. I'm not sure I would describe the ASUSA as 'better,' just different in this application. There was one modification I did to the Moondogs that might be coming into play: In place of the 100K resistor (grid-to-ground)in the input stage, I've installed 100k linear pots to help provide some attenuation control to match some of the rather high gain outputs of the preamps I have built. The Moondogs only require a couple of volts to swing the amp into full output, and lots of preamps, especially if used within close proximity of the amplifiers can throw the amp into clipping with very little effort. I now have my amplifiers 25 feet from my preamp and sources, and use homemade shielded interconnects that measure about 14-16 pfd/foot in capacitance -- which is lower than many cables. I'm now needing to turn the volume control up on the Moondogs approximately half-way to get decent output, which as a result is considerably lowering the input impedence of the amplifier (thus making it more difficult for the preamp to drive). What I think I'll try (a trick I read about on the Welborne Labs forum)is installing a 10K 'buffing' resistor between the wiper and grid of the first 6SN7 (great pictures by the way, Kelly!), so that the amplifier might 'see' a higher impedence as the volume control is rotated. Either that, or I'll install a fixed T-pad in place of the potentiometer. My speaker cable (cross-connected cheap coax) is also twice is long as it needs to be, and there may in fact be some capacitance/loss issues related to that. I had made a much narrower version of the popular CAT 5 speaker cable ($.35/foot from Radio Shack) that sounded absolutely stunning with my Lowthers, and have given those to a friend who like them better than his mega-buck Jena-Labs cable. The CAT 5 cables are what might be described as 'clean' and 'bright' which is what I like -- it sounds the way music used to sound when I played drums in jazz and rock bands years ago. That's why I love horn-loaded designs! They come closer to anything I've heard at reproducing the characteristics of real instruments. The Lowthers just can't match the low-end reproduction of the La Scalas, but have a midrange ability that is astonishingly good -- so is that of the La Scalas, by the way! In short, I'm going to pull the bonnet on the Moondogs today, and work on the input impedence issue a bit. I think the Moondogs have enormous promise, and I know many of you use them with your Klipschs. I wish I could share this little ASUSA stereo amp., though...it is so surprisingly good. I'll post results for those who might be interested.... You all have a good Sunday! Erik

Thanks for your responses to this post. The Lowthers and La Scalas made quite a visual statement, and I thought at one point that I had gotten a good balance using both speakers at the same time. Using a total of 3 amps. (Moondogs on Lowthers and a stereo on the LS), I was able to use the volume control to match the Lowthers fairly closely. I've since moved the Lowthers to another room, where they sound really very good. The bass the Lowthers are capable of in the rear-loaded Medallion loads the smaller space very well. I've heard that the Oris horns and La Scala bins make for a really great combination! Erik

...Well, I can relate to your sentiment about posting things of forums Kelly. But to the point! This is a great investigation of the 6SN7 tube. I'm looking forward to a more in-depth look early tomorrow morning, and I just want to echo your enthusiasm for this really fine tube. VTV fairly recently published a great line-stage project based on a design by Eric Barbour (an extremely talented, if often unorthodox designer). This is the same fellow who created the 'Pocket Preamp,' which I built a few years back. What's nice about it, is that uses a 5Y3 rectifier, as opposed to a solid state ciruit -- the 5Y3, by the way, works beautifully in the Moondogs! George Wright, I discovered, also uses 5Y3s in his 2A3 monoblock amps (I know of a few people who think Wright's amps are LOTS better in a number of ways than the Moondogs...) The GZ37 is just overkill (just my opinion)for a 2A3, and could possibly damage vintage tubes at the voltages Ron W. specifies in the Moondog schematic. Anyway, I appreciate your posting this great info. on the 6SN7, and look forward to reading the research you've shared with us. ...talk about procrastination! I'm supposed to be changing the connections on the Moondog's OPT secondaries right now, not posting on this forum! Erik

Hey, I don't know why I'm not getting your emails, unless they're somehow going into our 'junk' folder. Thats happened before. I sincerely appreciate your letting me have a listen to the AA networks, I look forward to receiving them....and will let you know when they get here. Have a good weekend, Erik

But what am I thinking?! All one of you had to do was hit 'reply'. It should have made it! Can we try again? Erik

Hello Edster and Tom: Thanks for your follow up on this, and sorry you had some difficulty emailing me. I've gotten successful replies from a few others via this forum, so am perplexed about the problem you're facing. My email address is follows (let me know if the one you tried is the same) shamaal88@msn.com Thanks, I look forward to hearing from you all. Erik

Hi, Edster - Just sent you an email. Hope I copied your address correctly. Let me know if you get it. Thanks! Erik

Hey - Almost reluctant to mention the words 'crossover upgrade,' I'm interested if there are any of you that had AA networks but aren't using them any more -- possibly having crossed-over (ok, that was pretty bad!) to an ALK version. ...and might be willing to sell them on a brief try-before-buy basis. Or if there may be some other place to look (?) This offer was posted recently, but I got to it just a little too late. Thanks, Erik

Disregard -- there it is!

Did I write about something I shouldn't have? I recently left a new topic regarding replacing crossover network parts with more contemporary/better components. The post was here previously, and now I don't see it. Was this something I should not have mentioned for some reason? Please let me know so I understand what is and isn't acceptable. Thanks, Erik

I feel bad that crossover thing I started turned into something totally different from how it started. You there, Kelly? Come-out wherever you are! Thanks for all you contributed to that, Guy. Erik M.

For those who have done some work on upgrading and modifying their LS or K-horn networks, have any of you tried maintaing the original shematic (AA AL, etc.)but simply swapped out higher quality capacitors and coils? I can't help but think there may well be some sonic improvement in substituting original parts with same-value parts of better quality and build. For example, removing the oil-can capacitors and replacing with the correct value Solen or Hovland. The same could be done for the inductors, which to me look rather thin in terms of AWG. Just curious if anyone has tried this before... Thanks! (I have to learn how to include my system components with my posts) Until this computer slow-poke figures that out, this is what I've got: Sources: Denon DCD 1015 CD Player Restored Eico mono tuner Nakamichi tape deck (becoming obsolete) Technics DD turntable sporting Walco MM cartridge (great for $$$!) Restored Heathkit AM tuner Preamplification (built from scratch on unfinished aluminum boxes) Bottlehead 'Foreplay' (design borrowed from George Wright) Heavily modified, using tube rectification and dedicated DC heater supply. With long cable runs to my amps, this is the preamp now in use due to its low output imedence cathode follower. Eric Barbour's 'pocket' preamp (uses a single subminiature tube!) This was also from an article in Glass audio. Bruce Rozenblit 'Line Stage', also from a Glass Audio *sometimes I just switch out preamps for the fun of it -- to hear them 'work' Amplfiers: Welborne Labs Moondog (Mods: 5Y3 rectfifer, reduced 2A3 plate voltage, cheap mylar coupling capacitors, volume controls on both amps) ASUSA K2003 (both amplifiers built from kits) Speakers: La Scalas (1989) Lowther PM2A Alnico drivers in Lowther-America Medallion cabinets ...I obviously need to make this a shorter list!

Jazman: That may be the best advice I've gotten out of this (first 'thread') now 'tapestry.' Thanks for passing on a more positive outlook on this subject. I guess, as is usual in audio, whether or not a modification (of whatever part or component)can be considered an 'upgrade' or and improvement depends on who one asks. Overall, I've gathered that some substitution of the original crossover parts (for truly higher quality)could be in order for my vintage 1989 La Scalas -- which I have to say sound very good as they are. Anyway, I appreciate your post, thanks for responding. Erik

Alright.... I am not the moderator of this forum, and don't pretend to have any authority of any kind. But as the originator of this thread, I extend an apology for bringing into question an issue that has begun to cause such fricton between some members of this forum. Erik

The idea: Lowthers in rear-loaded horns side-by-side with La Scalas. Lowthers driven by Moondog 2A3s, the La Scalas by a little tube SE stereo amp. Both amps driven by the same home-made preamp. My thought was to use both speakers simultaneously, using volume controls on the amps to blend the output.' The result: A. total lack of integration between the speakers. Non-existent or very confused imaging, much like a poor double-exposure photograph. Location of various instruments was next to impossible to identify. The plan: To not use both speakers at the same time! Simple enough solution! The thing is, is that the Lowthers are perhaps a bit more transparent in the high frequency range, and sound particularly good with small ensemble strings and acoustic guitar. The La Scalas handle complex music with aplomb, with outstanding bass foundation. But I wonder that one of Al's networks might open up the top-end a bit over the stock AL network. I am absolutely lucky in that I've enough space at the speaker end of the room for both speakers to sit very closely, side-by-side, without one getting in the way of the other. Horns seem to beam a bit more than more conventional dome tweeters, and so diffraction of high frequencie don't seem to be a problem. But what a wall of speakers to look at! I have built enough amplifiers and preamps to be able to actuallly have two separate systems in the same room, one of which could be devoted strictly to vinyl playback, the other to CD, FM, RR (once I get that up and running). I wish had the means and knowledge to post and illustration along with this written text (I don't know how to do that yet -- maybe my computer wiz wife can show me how). ...just sharing a Saturday evening experiment, Erik

I must admit that I was glad to find that the ALK networks were being made and were available to the public for purchase. Moreover, it is an absolute asset and benefit to this forum that Al K. frequents this site to share his knowledge and thoughts on this important topic. Granted, it took a couple of days to connect the designer/builder with the product (what can I say -- I'm a ditz sometimes!), but that discovery was one to be thankful for (ok....for which to be thankful!) I had seen the ALK networks in the pages of Audio Express a few times, and thought it was great that someone had been putting considerable time and effort into upgrading a key element of the Heritage line of speakers. This was even before I bought the La Scalas. Al uses among THE best passive components available, which no doubt contribute in a large way to the way they 'sound.' And this of course is reflected in the price he is asking. I'd buy a pair in an instant if I could, and have them on my list for sometime in the not-too-distant future. The holidays are getting close, and we have some other more pending financial needs right now. I've built other speaker systems in the past using most of the brands of parts Al uses in his -- and they DO make a difference! The coils and Hovland capacitors surely contribute to the cost. This post is already getting too long, but I just have to say this: At no time did I EVER feel Al was leading me into a purchase, nor did he ever fling a sales pitch. On the contrary! He was nice enough to provide me with contact information and part numbers for some of the parts in the network that needed to be special-ordered. Lets think of his presence as a positive, rather than a negative! There is not a large population of audio designers and engineers who make themselves and the fruits of their labor so available to the lay person. Since I enjoy building my own amps and preamps, there have been times where I had written to a certain designer, asking if they might possibly share some technical information about his/her product, and had been politely, but flatly denied. I understand the concern some may have regarding the use of forums as marketing devices, but I in no way see Al as belonging to or advocating such a scheme. Mr. Hornbuilder is another one of these that we are fortunate to have as a companion here. He's not going to the bank everyday with gigantic deposits from building nice looking cabinets for a couple of friends. Erik

C'mon you all... Please lets not make an assortment of coils and capacitors a personal issue. I really enjoy and learn from the different trials and experiments of those who have been working on these Klipsch for some time, but it bothers me if things start looking like a platform constructed to determine who is right and who isn't. Certainly I don't want to 'preach' or anything of that kind, but I do wish for open, friendly exchange that includes room for a differing of opinion and philosophy -- in other words, just be lighthearted about the matter. If there are personal issues to resolve, perhaps those could be worked-out, discussed, or otherwise reconciled in a more personal field? Al and Mobile (as he always has been) have been a very great source of information for me, as have others. I just think it would be most beneficial and constructive to maintain some objectivity -- both about the importance of relying on scientific measurement AND auditioning and listening. I kind of feel that these two camps don't need to be mutually exclusive, and that a bit of both might possibly offer the greatest reward. And hell! It suddenly dawned on me that Al is the maker of the ALK networks!!! Geez, sorry about that Al, I don't know what took me so long to figure that out?! I look at your very well-made/built networks daily (thanks again to Mobile H. for supplying his usual high-quality pictures), wishing I could put in an order right now for a pair. As Kelly said in his compliment, it is not everyday that a company is willing to make public its 'schematic secrets.' Parts for the 'A' network can be bought at Parts Express for a reasonable amount -- of course the transformer would have to come either from the original network or Universal. Enjoy the weekend, Erik