Erik Mandaville Posted January 23, 2003 Share Posted January 23, 2003 I've become increasingly interested in characteristics of OTL amplifiers, and am curious about whether there are forum members here who have tried or use them with high efficiency horns. Transcendent sound (www.transcendentsound.com)is a company for which I'm gaining quick respect, and they have a variety of products (kits or pre-built)available for prices that I'm finding are pretty hard to beat. There are some Transcendent Sound amplifier users that have described Rozenblit's designs as 'quicker' and 'resolving' (etc.) than the 2A3-based amplifiers (obviously transformer coupled) they formerly used to use, in fact, describing 2A3s as 'sluggish' by comparison. There are other companies that 'specialize' in OTL (output-transformer-less in case you are not familiar with this), but not even close to an approachable price -- at least for me. Any thoughts or experience would be very much appreciated! I'm seriously thinking of buying one of Rozenblits OTL kits, or building from scratch from his one of his schematics. Thanks and regards, Erik Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted January 23, 2003 Share Posted January 23, 2003 The OTL I have heard have been the opposite of the stereotype of tube sound. To me, they sound lean and more like a surgeon's scalpel with less harmonic warmth. While the detail, which appears almost exaggerated to me, is impressive, especially on first listen, long term exposure does not bear musical fruit. If you are after the exaggerated detail of highlighting of fingers on the fret board and the breath of the first violinist, then they can be magical. I have found other designs to offer a better top to bottom balance and sound more natural on top of that. Still, the OTL has strengths. I just find that living with them produces the typical listen to sounds approach to music over enjoying the full emotional impact. To me, the emotion and life of the actual recording/event is left to the wayside. I also find the OTL I have heard tend to have a more steely approach to the presentation. I will say I have never heard an OTL amp in my own home only sampling them in others. As always, opinion must be noted. IF one could come up with the best of the OTL with the best of the more musical examples, they would have a fine mix. For me, the OTL approach errs on the highlighted detail approach with a slightly more mechanical bent. I have found Bruce Rozenblit to be quite the promoter and one that tends to use measurements and science to back up his opinion, while sometimes hiding the fact that it his viewpoint and that science is not always best served with the hidden aspect here. His second book was especially troubling. IT was more like "Bruce Rozenblit against the Audio World" and more transparent than his OTL amps. Enjoythemusic.com has an interesting review of it that seems pretty on the mark in my opinion. His basics of tube audio book is far less plagued with this vantage point. Although Bruce is not a proponent of zero feedback designs in any shape or form. He is wary of all forms of distortion in equal measures from what I remember. The first book is more recommended than the second in my view. kh Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted January 23, 2003 Author Share Posted January 23, 2003 Hmmmmmmmmmmmmmm. Sounds like OTLs might be just what I'm looking for! Your post is confirmation of this. I've been in communication with Jeff Lessard on this matter as well, and he has provided some very insightful information on the subject -- as well as a mutual interest in some of the obvious benefits or transformerless coupling to a speaker's voice coil. Although I may not agree on every point Bruce Rozenblit may make, I am not in the position to deny his level of understanding of audio electronics, indeed of electronics, in general. His knowledge and experience is signficantly beyond my own, as I would venture to say -- based on much I have seen and read recently on this forum -- likely beyond many who frequent this site. As you yourself said, most people here don't build their own amplifiers. However, I very much respect the fact that most, if not all people here know damn well what they like and prefer in terms of music reproduction in the home. And that's why I like to come and share in the experience of others. Your subjective description of OTLs sounds outstanding to me. Opinion thus noted! Erik Quote Link to comment Share on other sites More sharing options...
Chris Robinson Posted January 23, 2003 Share Posted January 23, 2003 Erik, if you walk down that road, please keep a diary and report your progress in the neutral journalistic manner we've grown accustomed to! God Speed. Quote Link to comment Share on other sites More sharing options...
Colin Posted January 23, 2003 Share Posted January 23, 2003 you have big old horns and Moondogs ... and you want to go OTL??? Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted January 23, 2003 Share Posted January 23, 2003 Funny. I thought J-F had gotten past that. He's been fooling me, again. After spending 15 years shooting for the "breath of third violinist" approach to audio and getting pretty successful, I realized that it was moving me farther away from the music, figuratively and literally. I was listening to less of the music I loved. I was listening for sounds. I was going after the best recordings sonically, which tend to be the least involving mentally or emotionally. I was putting myself every day with people that knew virtually nothing about music but all about the gear. In addition, the result was not musically satisfying, this, the most important aspect of all. Frankly, it was as empty as a sea of landscapes at the ART FOR CHEAP truck down on Third. IT had very little to do with music; in addition, I found the gear that accomplished this majored in leaving the soul of the performance behind, which turned out to be worth VERY little to me. IT was an exercise. I found it missing the core of what music was all about. The assumption that getting the details would bring you closer to the music was not bearing musical FROOT with me. Now, I love resolution. I love details. I love top end extension and natural treble. But I don't like anything exaggerated. And I have become very sensitive to the artificial nature of reproduction. Ironically enough, both my current rigs have tremendous detail and an amazing open quality. Harmonic detail is there in full bloom. But the hyper etched version of OTL take is not for me...that is, unless they can do it while bringing the rest of the essence of music to the table. The strange thing is those that seem to quest for this, don't have much of a music collection. A painful irony. As for Bruce Rozenblit, I go by what I read, hear, and experience. Rozenblit is just one more on the list here. I find his on foibles coloring his take on things which is par for the course with humans obviously, although some are far worse than others. Give the OTL a try. As I said, if that is your game, and your pinnacle to shoot for, it might provide you with the end run. I even have a few extra CDs I can send over with notes on where you should hear the page turn and that very breath in question. kh Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted January 24, 2003 Author Share Posted January 24, 2003 Thanks for you encouragment, Chris. KH: I seriously doubt that Jeff L. is fooling you; pulling the wool over your eyes; passing things under-the-table, or planting any other form of smoke-screen-disguise. From communicating with him, I have learned he is very well versed in terms of vacuum tube theory and application, with lots of building experience to buttress and support the 'book' aspect of what he knows. Moreover, he is a friendly person willing to share the excitement of building with others who share a bit of the same passion. I have always enjoyed constructing: I was welding together shock-absorbing bicycle frames when I was in 6th grade, and learned to solder (I used to build little 'creatures out of tin can) when I was 5 -- it was the only way I really got to spend any time with my dad. I mentioned he has a lifetime of knowledge about tube electronics. Everytime I think I understand something new, I realize how really little I truly know! But I am trying, and it gives us (my pop and me) something to talk about. I'm not going to waste time commenting on the size of my music collection. I will submit that it's not so much the size that matters, anyway, but rather how much one enjoys and appreciates what one has. Please note that opinion. I have read about OTLs for several years, and have am curious to try one -- as much for further experience in building as for the kind of reproduction it will provide. I enjoy the Moondogs very much -- that much you know. YOu might find, Kelly, if you ever start to construct some of your own equipment, that it can provide a great deal of satisfaction. And I must submit to you as well, that experimenting with different circuits does not at all have to translate into a lack of time listening to music. If you consider the amount of time 3,000+ posts (very informative ones, often including marvelous illustrations presented in a professional manner)takes, I don't see anything wrong with taking a similar amount of time on Saturday mornings learning to build and repair tube equipment. It's what I like to do, and then spend very focused time in the afternoon and evening listening. Regards, Erik Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted January 24, 2003 Share Posted January 24, 2003 Beautiful. kh Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted January 24, 2003 Author Share Posted January 24, 2003 "Beautiful"??? Another example of how our aesthetic sensibilities strongly differ. Quote Link to comment Share on other sites More sharing options...
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