Why no threads on OTL amps?

I looked through the old thread list and didn't find anything on OTL amps. How come? Does nobody like them? Is there something wrong with them? Would you buy/notbuy one, and why? If you would buy one, which one do you like best? I always thought OTL was the best, but there doesn't seem to be much interest here on this forum for them.
Nothing wrong with them, in principle, just that you have to make damn sure the rest of the equipment you have them hooked up to is impeccable sounding (inc. the recording), otherwise, you might not enjoy the sound. Also, there are not that many speakers whose nominal impedance is around 16 ohms (and thus a good load for an OTL) ... Coincident of course comes to mind.
Joule Electra and Berning and Transcendent are the better makes, Tenor probably the best. A writer in the Absolute Sound went gaga over the Tenor/Rockport display at CES in January.
That's my dream system, really: Tenor amps, Wadia Digital direct to the amp, and Coincidents biggest speakers! But we're talking $30,000 or more!
Someone about a month or so ago put a thead up on best amps for wilson/watt puppy 6's. In it, lot's was discussed on OTL's. try that search...
OTL amps are sonically amazing, however alot of people are afraid of them because of reliabilty issues, incompatible speaker matching concerns as well as the massive power consumption the bigger OTL's require and of course tube life. Very few OTL's (almost none of them can handle under 2 ohms for long and certainly not at higher spl's) can be used with a wide range of speakers with large impedence swings however, very, very few can do this and most of the ones that can typically require about as much energy as a small power plant when driving full range speakers at reasonable levels and create enough heat to dismiss the use of a furnace during the winter months :)
There are numerous threads about OTL's here at this sight, try a search for any of the manufacturers names of OTL amps, that may provide better search results. In the paragraph above, I attempted to illustrate a brief summary of why alot of people dismiss the use of a typical OTL because of obvious limitations and operating characteristics. There is however a special OTL amp I know of that can easily tolerate difficult impedence swings, does not require massive amounts of power at idle or at peak for that matter and has a tube life of 4 or 5 times that of a conventional OTL is the David Berning ZH-270.
Many have a misunderstanding of what the ZH270 does to accomplish the difficult task of tolerating impedence swings throughout the frequency spectrum so I will attempt to summerize this highly advanced design as simply as possible:

You see, the ZH270 is the first OTL amp that can properly match the high voltage, low current operating conditions of tubes to the low voltage, high current requirements of most dynamic loudspeakers without the need for audio-output transformers. The 270 does not require the use of banks and banks of tubes to achieve a significant amount of power to the loudspeakers. This is done through the use of RF (radio freq.) which allows the voltage-current characteristics of the tubes from their normal impedence plane to one that is ideal for driving dynamic speakers.

Is everyone still with me??, I hope so :)

Ok, the RF re-mapping occurs through the use of a tiny RF transformer at a carrier freq. of 250kHz. As a result, the audio signal gets a care free ride on the HF wave and is therefore not subjected to any parasitic elements that would otherwise be present. The 270 is DC coupled with the exeception of a small high quality DC blocking capacitor at the input of the amp.

Alright, I'll stop with the technical babble unless anyone else is interested in hearing more about this breakthrough OTL design (there is much more that can be said about this special amp, I'm serious) :) Look around for an OTL that weighs 10lbs and can drive anything, your search will lead you to the same little OTL time and time again. It puts out the most powerful 70 watts with the most drive I have ever heard from any amp.

No other amp sounds like a good OTL, neither SS or traditional tube amps can imitate the incredible sonics of an tube amp without transformers. The OTL sound is in a league of its own in many ways. I highly recommend listening to an OTL amplifier, I think then you will understand why OTL owners are so passionate about their sound.

Best Regards,

I think any mid to high-efficiency speakers (i.e. 89db and up) with 8-ohms (nominal) impedance will work just fine with most OTLs. Unfortunately too many of the popular high-end speakers tend to work at much lower (4 or 5) ohms. I bet one reason for this is, most people end up buying high-powered SS amps over OTLs or even SETs. I own a low powered (20 wpc) Graaf GM-20 OTL -- my speaker choice was a pair of Kharma Ceramique 2.2 over more the popular Wilson Watt-Puppy.
Well there have been threads on theses marvels but there doesn't appear to be too much experience. Many steer clear of tube amps because of the hassle, an OTL even more so because of the heat output and the impedance restrictions with perceived reliability issues in hot pursuit.

With the right amp to the right speaker, isn't there always a catch, there really isn't anything NOT to like. To me, at their best with the proper load they are the ultimate, a conjoining of the virtues of both ss and tubes that being speed, clarity, presence with incandescent highs and very well defined controlled bass comparable to the best out there. The key again is amp/speaker interface.
Chris is right on concerning the incredible Berning ZH-270 OTL amp. I bought one used about a month ago and am astounded at it's sonics and capability.

I was a little apprehensive about it's ability to drive my Aerial 7b's. These are not considered tube-friendly, being 86dB, and 6 ohms with a wide impedence swing. But to my delight and surprise, it doesn't seem to have any problem with them. The Berning can drive them to very high levels in my 20 x 21 x 10 room. I have a combined 2-ch/HT system, and use the Berning not only for 2 ch listening, but for HT on my L/R front speakers as well. I know you'll find this hard to believe, but it handled the opening battle scene on the Gladiator dvd better than my EAD Powermaster 2000. And it's got 400 watts x 5 channels compared to the Berning's 70 watts.

I've got a REL sub connected to the high level input of the amp. During the most dynamic sequences on the dvd, the EAD would shut down due to the low impedence of the combined load of the REL & Aerial's. The Berning didn't miss a beat. It delivered all the volume and impact you'd want. Simply incredible.

I'm now considering selling the Aerial's and replacing them with a horn speaker. I'm told there's nothing like a "good" horn to bring realism into the listening room. While the Berning will be overkill from a power standpoint, I feel confident it will deliver sound to die for.

This is not a well known amp. The only reason I was aware of it is because two of my friends each owned one, and kept telling me how great it was. I forgot to mention it's versatility. It's got 2 RCA inputs, and a quality volume control. This allowed me to run both my cdp and front HT channels directly to the amp. It's got more than enough gain for both. I'm now debating on whether I need my Joule Electra preamp.

For a small 10 lb amp to deliver this kind of performance and versatility, not to mention the 10-20 year lifetime on the tubes (it's already got 4 years on them and going strong) it's a miracle product. If you get the chance to pick one up, don't let it pass. You won't regret it.
Tacs-You'd need a lot more then 30k for your dream system, the amps alone are $19,995 per pair. I have spent a good deal of time listening to these amps on a good friends system and they are as good as everyone says, perhaps better. OTL's are incredible, though they have there set backs, for me its cost!! other then that I would have them.

oh and btw I concur with both Chris and Ken about the Berning. You WILL be amazed at its sound, versatility, price and weight/performance. The hardest part is just getting past the small size. Then you listen, no way man, how'd Berning do that? The zhotl is the latest incarnation of "the little engine that could".
Hi Tim, what speakers is your friend using with the Tenors if you don't mind?

Chris-He is using Verity Audio Parsifal Encores, which isn't a very good synergistically. We switched back and forth from the monitor and the whole speaker and it sounds much more like music with just the monitor which is surprise 8 ohms and with the sub(encore) its 6 or 4 ohms, which isn't great for the amp. He is currently looking for speakers and he and I(mostly he) have been listening to everything we can find. Still nothing amazing, we are looking at everything between 7,000-40,000 its scary how little is actually out there that will work. I use avalon eclipse and think they would mate up well with the amps, but they don't have what he is looking for, no two of us are the same.

Hi Tim,

I had a chance to listen to the Tenor's running a pair of Lamhorns(I think)at the Montreal show this weekend. The sound was very nice. In fact I felt the tenor and the ZH270 shared in some qualities. The ZH270 at the show was running a new speaker, made by Preference Audio. The sound was amazing. The Berning in my opinion bested the Tenors in every way. Speed, clarity, bass, and of course that magical otl midrange. Being that I am a Berning owner I may be a bit biased, but there were many other people who felt the same. I have even heard the ZH270 running a pair of full range soundlabs at a friends house with ease, which the Tenors cannot do. In my opinion, the Tenors were wonderful amps, but I cannot justify the incredible cost difference, and the speaker limitations that one encounters with the Tenors.

Happy listening,

Kris Kosiba

I imagine the soundlabs and Tenors wasn't that greatest set up, wolcotts would have been great though! The tenor's are very speaker dependent find a GREAT speaker like Rockports, Kharmas, Piega, Talon, etc.... you have magic but on the wrong speaker it doesn't do them justice. Keep in mind I own BAT tube amps, and my opinion is completely un-bias. Anyone who heard the Tuscany Room at CES knows what I am talking about, something VERY magical happens when the system is right with these amps.

You mentioned the Berning ZH270 running a speaker by Preference Audio. I'd be very interested in learning more about this speaker. I couldn't find anything on Preference Audio thru the Google search engine. Can you provide me with any additional info that would allow me to track them down?

BTW, which speakers are you running with your Berning?


A bit off-topic. Could you tell me more about Berning at Montreal show? I could not found any coverage about Berning anywhere so far, including commercial and personal show report, zero, nada. I wonder why? I intend to give it a listen and waiting for the opportunity (thanks, Tubegroover!), and would like to know how Berning did at the show. Thanks! Ken
I think OTL is alive and well but many are put off by the incredable heat these amps put out except for Transcendent and I also think that the low watt/ high efficency lowther type horn speaker crowd is taking over big time. You can't beat the dynamics of this type of system with any normal speakers/ high power amps period. I'll take a Art Audio Px25 (6 watts)amp and a pair of $400 Loth-x speakers over any 40watt and up system just for the musicality and emotional impact.
Hello Kenl,
I am going to try to answer the last two messages. Kenl, Preference Audio is a brand new company which is from Quebec. I had a chance to listen to these speakers(which are appropriately named "Baby Bears" as they are large 175lbs each) and they were quite nice. They use a Horn Loaded tweeter and a ten inch woofer. They were extremely well built. They are also quite efficient. 93db, so the Berning was really driving them with utterly no strain. I was able to get a card as well. The designers names are Claude, and Guy, and can be reached at (450)349-0021. These speakers were wonderful.
In reference to the question about coverage of Berning products at the show, I doubt you will see any. Though it was by far one of the best sounding rooms in the show, David Berning does not advertise, and therefore most likely will not be picked up by many of the magazines. I did see Audio Asylum in the room taking pictures however, so maybe something will show up there. For any other information including reviews refer to the David Berning website, or Allan@Hellosimplymusic.com Allan would answer any questions you might have. I Hope this has been of help.

Definitely include the Berning 270 for OTL's which put out little heat, the 270 puts off very little heat, in fact less than any other OTL I can think of. It also does not use much power from the AC - 100W@idle & 300W max. and increases output power into lower impedences which no other OTL does. This is really breakthrough technology for OTL tube amplifiers.

I took my ZH270 to my local high end dealers' for him to listen to. It was sitting on a rack, and a customer came in and saw it and asked the dealer how he could cook anything in such a small microwave! Later, a little kid came in with his parents, saw the 270, and said "Wow! An EZ-bake oven!" True stories, but may also illustrate why the 270 sometimes doesn't seem to "get any respect"--it just doesn't look as impressive as some of the others, with rows and rows of output tubes in each mono-block.
Regarding Berning, my dream amp is the Seigfried: a 300b ZH type OTL w/12wpc and dual volume pots to allow direct input. It's killer. And like the ZH270, it will drive low impedances with authority. Talk about perfection, a 300b, pure class A single ended triode, ZH type OTL,with low heat/low power consumption, 20 year tube life, direct input capable, and drives difficult loads and is extremely reliable. And I believe, auto bias adjusting. I think it's around $7500. I'll bet it will squash the Tenor amps flatter than a pancake. Looks really cool, too. BTW, I have the Berning MicroZ OTL(1wpc,pure class A triode) and it is a jewel. I have NOS tubes(Mullard 6201,Sylvania 6sn7wgt) in it and there is no way I could describe the performance level(that you would believe, anyway). You have to audition one of these, with good single driver high-eff. speakers. It will knock your socks off, and you will never think the same way again about low power amps. All the accolades spoken above about the ZH270 also apply to the MicroZOTL. If you choose your speakers to match it, you will never need more amplifier.(Maybe a separate sub/amp if you like that set up). Also, it makes a great bi-amp system with one on each side for inexpensive OTL bi-amping if you like 2 way speakers, or even a crystal clear tweeter amp for multi-amp systems. It even has a headphone output jack. No one that has listened to mine believed it is only a $750 amp. Very highly recommended.(It will also run on a 12vdc battery which completely eliminates power grunge problems and the entire 120vac power supply section, or you can just plug it into the wall if you want, no wall-wart, uses IEC connector so you can use the super duper power cords, too.
Kris: Your statement of "The Berning in my opinion bested the Tenors in every way. Speed, clarity, bass, and of course that magical otl midrange", is quite a reach considering you were listening to two entirely different systems. That is like listening to a system in Montreal and saying did you hear how good those power cords were? It just is not a real valid statement.

Since I have not heard the Berning amps in my reference system, I will not make any statements as to whether they are good or bad. It would be impossible for me to do so with a clear conscience.

The Tenor amplifiers are the finest amplifiers I have ever heard. Nothing I have heard is even close and that is why I took on the line. The Tenor's can handle impedance swings as well as any OTL. What they do not tolerate is what any 75 watt amplifier would have a problem with, inefficient speakers. I have had them on 86 db Eggleston's and they do great within a reasonable limit. If you are looking to drive an 80-86db speaker at over 100db, these amplifiers are not for you. I know at least two people driving Watt Puppy 6's with a pair of Tenor 75's and they could not be happier. The 6's are a 4 ohm speaker that drops to about 2.

Twl: Your statement of "I'll bet it will squash the Tenor amps flatter than a pancake" is quite funny and I will be happy to take that bet anytime you want. How much money you have? :)
Twl-When you think of SETs you think of the late Gizmo Harvey Rosenberg of NYAL's fame. He went absolutely bonkers over the Seigfried and the zero hysterisis technology in general. The ultimate realization of tube technology today must include the Siegfried with either the 300b or 811 triode. Imagine a low powered SET that isn't limited to that magical midrange but expands its performance into the high and low frequencies as well. Regulated switching power supply and an OTL output stage, dead quiet, auto biasing, reliable, low heat and elimination of transformer related distortions. Where do you go from there? I guess it can be refined but in reality Berning has established a new path and there seems to be a hush over it in the audio community. I haven't heard this amp yet but can only guess that it sets new benchmarks for SET design and may be near the pinnacle of reproduced audio with the right speakers for those looking at this approach. There is much to be said for low power and highly efficient speakers. The zh270 itself is so incredible that you really have to wonder about the advanced level of design and engineering in these special products. I haven't stopped wondering since I got mine over 2 months ago.
"The Tenors can handle impedence swings as well as any OTL."

Not true actually, the Berning OTL's INCREASE output power into lower impedences. The Tenors cannot do this simply due to the nature of their design. This does not mean they are not great sounding amplifers, it just means they will have to struggle more with more difficult loads than a single ZH270. Lets quickly look at a couple specifications -

Tenor 75wi (monos) - @ 4, 6, 8 ohm - 55, 75, 75W respectively.

Power consumption - 730W (not indicated if this is idle or max.)

Berning 270 (stereo per channel) @ 8 ohm - 70W (84W output at onset of clipping), 4 ohm - 110W at onset of clippin.

Power consumption - 100W @ idle, 300W max.

I doubt the Tenors (or any other OTL) withstand less than 2 ohms or less for very long without losing steam, they were not designed to drive those difficult impedences with any consistancy. A ZH270 I know for a fact will tolerate quite low impedences for extended periods AND can provide much higher ouput power into lower impedences because of its unique ability to match impedence.

For example -

I personally heard the ZH270 drive a pair of Magnepan 3.6QR's LOUD with lots of drive tolerating some huge dynamic swings while playing some crazy techno music. For the kind of headroom we had one would think we were using some big solid state bruiser, but we weren't. We were using a single ZH270 with the difficult to drive Maggies.

Any 70W amp has its limits, true but we are discussing the subject of OTL amps specifically and I would welcome a friendly comparison with the Berning ZH270 and a Tenor Classic 75wi. I am confident a single 270 would do more than hold its own with the Tenors, especially with difficult to drive speakers like the Magnepans and/or ESL's for that matter.



This is an link to an image of a cutting edge, state of the art designed OTL amplifer made by David Berning based on ZH technology used on his current product line up.

As you can see by the internal layout, this is a radical departure from the conventional OTL technology based on Futterman principals some 50 years ago.

This mono block weighs 8 or 9 pounds and puts out 120W into 8 ohms and INCREASES output power into lower impedences.

Just for a minute, think of all the limitations and drawbacks associated with the current OTL amplifiers. Now think about one without these limitations, not possible? Incorrect, it is possible and happening right now.
Jtinn, my recommendation to you as a dealer would be to audition the Berning line in your system. I believe that if you do this, you will pick up that line as your new reference standard. I am sure the Tenors are exquisite amplifiers that anyone would be proud to own,with great sound and beautiful build quality. I do not intend to knock them and perhaps went overboard with my "flat as a pancake" statement. However, as Tubegroover stated, Berning has established a new path for OTL that creates a new standard in the OTL field. The typical circlotron OTL circuit topology has been superceded. The inherent circlotron weaknesses have been replaced with a superior design. And, of course, the previous cathode follower and Futterman designs had been surpassed years before by Ralph Karsten and his Atma-sphere circlotron design. I love OTLs and all of the great amps out there that use OTL design. I just have to recognize that there is now a superior design that will take us further toward OTL perfection, and that design is the Berning Zero-Hysteresis OTL amplifier. Cheers.
A little surprised not to have noticed Atma-Spheres on this thread. Compared to the other amps I have owned, tube or solid-state, the MA-2's have outperformed all in nearly every category. Bottom slam, midrange transparency, and extension up top...all beautiful and musical. This, of course, is with the system I have assembled. Avalon Eidelon, Jadis preamp, CEC/ Audio Note digital, Clearaudio TT, FIM cable. I have enjoyed many systems, but none for as long or as consistently as that which I have forementioned.

Reliability has so far been a non-issue. The 220 watts/ channel offers more than enough juice. The heat generated is something else. My room must increase a good 8-10 degrees. Great in winter, but summer....

I have not compared to other OTL's but reports on performance carries similar subjective remarks. A cleansing in clarity, bringing the listening experience closer to the recording venue. Must be heard in a well designed system.
Thorty 40, I couldn't pull up your URL with my search engine. Would love to see that design. If you could find another way for us to see it, it would be much appreciated.
Twl, well put, your comments hit the nail right on the head. Why do so many seem resistant to the thought of a more evolved OTL design? That is my question.

Try this -


Then goto SLOG on line, view archives, on line archive 1, scroll to roughly the middle of the posts and find "here's the correct image" by Brian Walsh 10/24/01 and click on the thread.

That will take you to the picture.


Thanks, Thorty40, very cool pix.
The Berning ZH-270 is just a marvelous amplifier that can drive many speakers with ease. This amp is very musical, quiet, and has lots of drive! The ZH-270 is revolutionary and best described by Thorty40 and Kenl. I love my ZH-270 and would only consider replacing my present system with a Seigfried or Art Audio amp with a high efficiency horn speaker.
Let me join Siddh in praise of Atma-Sphere OTL's, neglected in most of this thread. I'm using a pair of M60 II.2's with half their output tubes removed, with Quad ESL 63's, whose impedance drops as low as 4 ohms though is mostly closer to 7. The point being, that's high enough. Not the 16 ohms some OTL's may need. Reliability is fine too. I did an odd experiment, using a Pass Aleph 3 as a monoblock (input and output both paralleled) for one speaker and a M60 II.2 for the other. There was nothing clearly wrong with the Aleph 3 sound, as I switched back and forth on good mono material, but I preferred the warmth of the M60 II.2 sound every time. I wasn't giving up anything, detail, transparency, certainly not palpability if we may speak of that, as far as I could tell. That made me decide I was a tube person for life.
C'mon, where are the Graaf and Croft people? And how about the Transcendance folks?
Twl I am also a Transcendent folk, still have it. A great little 25 watt amp it is. This is the one that brought me to the realization of what OTL amps are all about. I doubt that you can do better at the price and power rating.

Regardless of which of the OTL amps that are choosen for a given application and load the one indisputable fact is that these amps as a group are uniquely special. After all, this isn't a p...ing contest, is it? I have not had the priviledge of hearing the Joules, Graff or Tenor but I'm sure they have their virtues and that each might be picked over the other in a given application.

My problem with Siddh's choice is that I can't live in Florida with an increase of 8-10 degrees in my room, the plants would wilt and so would I. I'm sure I could live with its sonics which by all accounts is among the best. But 220 OTL watts, must put out 1200-1500 watts at idle. I guess I could settle for the M-60's, still a lot of heat. This is why I went with the Transcendent originally but ultimately it didn't have quite enough headroom with certain music.

The Atmaspheres, Joules and Tenors may be better on an absolute level than the Berning with a given speaker system. The Berning would be a better choice for me with my speakers and probably would be a better all around choice for a lot more audiophiles. What other tube amp increases power ala ss into low impedance loads? Transformers saturate and compromise the bass and high frequency performance and OTL's start doing crazy things to the dynamics of the music and become unstable into such loads. Well you just add more tubes to up the current. Sounds like a great choice if you live in a cool climate or have a dedicated venting system for the amps. This is the whole point of Bernings' design.
Cool post, Tubegroover. All modern OTLs take the music one step closer to the truth. One comment I would make about the load stability is that the large number of tubes is also an attempt to lower the output impedance of the amp, not just current drive. The output impedance of the Berning amps is 2ohms or less, depending on model. And this is the case with relatively few tubes. This is the real breakthrough in the design in that the RF carrier system replaces the output transformer's task with a much higher turns ratio than possible with iron. Thus allowing fewer tubes, better efficiency, less heat, and a lower output impedance than previous OTL designs. And, it's not really in the signal path, just carrying it. Grid drive. Not cathode follower or circlotron. All new. With previous OTLs, damping factor was a problem because the amps output impedance was high enough to sometimes be above the load impedance and damping was seriously compromised.With a 2ohm output impedance the Berning design breaks new ground with respect to damping and does so with few tubes. In fact, in my MicroZ OTL, the output tubes are 6sn7's. Normally a preamp tube, and a great one. Tube heads out there know that preamp tubes are generally much more linear than power tubes. This is really the first time a linear tube such as the 6sn7 is actually driving a speaker directly. It is amazing. And very short signal path, too. Detail is dramatic. Midrange is liquid, and bass is fast and solid. The sound is balanced from top to bottom. If you just take the sound, not the power level, it is the equal or better of anything there is. I can't believe that I could afford such a thing, but here it sits - all 4 pounds of it! Must be a dream. David Berning is a genius to have thought up this level of tube "groovosity."(As Harvey aka Dr Gizmo, called it)
I agree, OTL is where its at.I hooked up my Futterman design NY labs amps to a pair of 15" Tannoy dual concentrics I picked up at a garage sale two years ago, and could not beleive what I heard, amazing natural music, I relax when I listen to MUSIC, not HI-FI.I put away a pair of Quad 63 US Monitors,and a pair of Magneplanar Tympanis and just listen to a pair of 40 year old speakers. By the way the Tannoy speakers are 15 ohm.There is some serious synergy between amp and speakers. I would love to hear from others using same/similar gear. Tubegroover is right, OTL is where its at.
I also own a Berning amp. I used to be a solid state kind of guy until having an epiphany regarding OTL tube amps. I listened to an Atmosphere amp and was blown away. I started researching OTL amps and became interested in Berning amps because of their novel technology. After listening to ZH270, I bought it. I recently changed to horn speakers and didn't need the power of the 270. So I sold it and purchased the 811 ZOTL. It has all the attributes of an OTL amp; clarity,speed,soundstaging, along with the SET midrange magic. I prefered the sound of the 811 over the 270. I think it has something to do with it being Class A with no negative feedback and single ended (unlike the 270).

Which horn speakers did you settle on? I own a Berning 270 and am myself interested in horns. Did you try the 270 with the horns before selling it? How did it sound?

I have a pair of Avantegarde Duos. I found that I needed the integrated subwoofer to really enjoy all types of music. I didn't like the single driver(full range) speakers--no frequency extremes tho they do midrange very well. As to the amps, I did compare the two. The 270 sounded great but in comparison to the 811 was more OTL-like e.g. faster and slightly harder sounding. The 811 had slightly more midrange bloom but most importantly for me was that I started listening to the music and forgetting about audiophile sonic attributes like soundstaging,speed,
detail,etc. With the 811 the speakers completely disappeared. Hope this helps.
I had the Berning amp here for six months and then sold it after hearing the Tenors and amps from Exemplar Audio. Both were superior in every audiophile parameter you can think of on Merlins VSMs and Beauhorn Virtuosos
Srouse, I haven't heard the Exemplar amp. Did you hear a 2A3 or a 300B? Checked into it at the Bottlehead site. It seems that he(John) has gotten some input from the Bottlehead people on his amps. Bet they sound great.90kHz bandwidth, must be a helluva output transformer!
Jtinn, BTW, Kris is entitled to his opinion, just as you are. Just as I am. Please do not feel threatened if another amp line surpasses your favorite. It happens to your customers all the time, when you have something new and great to sell them. Probably doesn't bother you a bit that they are going to take a bath on the money they lose selling their old gear and paying you profit on the flavor of the month. After all, how else would audio businesses continue to make money. I've worked in several audio emporiums and know people that worked in others, been to CES, and other shows and rubbed elbows. I know the comments that are made between dealers and mfrs. It's all about churning. Just like the stock brokers: buy, sell, buy, sell. How many "turns" will you get on a particular product in a year, is the major concern. And how much margin. Hype the latest hot item, and next month hype the next. If a customer's system gets superceded by a better(newer) product, well "that's just the electronics biz." But if you've got $350k tied up in the minimum stocking order to retain a dealership, then you better believe that amp is going to be the "best you ever heard".I hate to be this hard on you, but you threw down the gauntlet and now I'm telling you that your opinion cannot be considered objective because you have financial interest in certain products selling well. Conflict of interest, I believe, is the term. You should recuse yourself from this discussion due to conflict of interest.
Twl In defense of Jtinn I would like to say this, he has always let it be know he is a dealer in each thread he is involved in where he offers an opinion or rave. I certainly sense his enthusiasm for the Tenor and have come to highly respect his input. The Tenor has really gotten high praise from every corner. Then again I would expect nothing less based on its price. If it turns out to be a mirage, the company won't last. I would love to hear it in my system but I could never justify to myself (or wife) spending that much money on an amplifier.

I am probably not as critical of this as you might be since you are an insider and better know than I how it works. You make some interesting points. I on the other hand have never been involved in the audio industry. There is not one individual that could ever pursuade me that one thing is better than another. Only my ears will do that. One of the most important things I always try to convey to anyone seeking my opinion is that yes, you may respect it but to ALWAYS trust your own ears first. Opinions from trusted peers just help narrow down the choices.

I also feel it is useless to compare two completely different and unfamiliar systems and try to attribute the sound of one over the other to a particular component, there are too many variables. The big plus for the Berning amp over the others is not whether it is the absolute "best" but all the pluses it offers over other OTL's including cost. My assessment using that criteria is, nothing I'm aware of comes close. Others may look at that comment as a compromise when to them only the "best" counts regardless of anything else. Unfortunately best often times is associated to price and it is not always true.

And thanks Twl for starting the thread. I hope it has the benefit of opening the eyes and ears of those that are looking for something they haven't yet heard that resides only in OTL designs.
Just for the record Tubegroover, I haven't worked in audio for almost 10 years now. I feel bad about hammering Jtinn like I did, but when you are an audiophile and you hear stuff like I heard at trade shows, it really scorches your hide. They want to herd us around like livestock to the slaughter with their hype and magazine reviews. Now, I know there are alot of great products out there and I am not going to say that 1 product is best for everyone, and am sure that you or Jtinn would feel similarly. I am just very sensitive about the revolving door of product hype based on the need to sell. Sorry If I offended anyone(Jtinn). I have no knowledge of him personally doing any of the negative things I mentioned above.
Twl: The comment you made has no foundation on fact. You heard two totally different systems with all different components and made a statement about the amplifiers. It is improper and highly incorrect (maybe subjective). I do not need to recuse myself because I do not feel I am improperly participating.

I agree with your concerns about the audio industry and feel as do you. I do not need to sell anything or hype anything just for the sake of making a buck. I like music and what gets me closer to the live experience. I enjoy helping others in that search as well. If it is profitable, at times, great, if not, great too. I think most people I deal with respect the fact that I have a decent ear and speak of what I know and have experienced, not what makes me money.

You seem to be a straight shooter and talk passionately. I respect that and look forward to your future posts.

Best Regards,

If I read this correctly, it seems to me that twl's criticisms of certain products being "flavors of the month" and individuals possibly "taking a bath" on resale of said products, could be accurately applied to srause's experience with the Berning, no? Hmmmm.....
Mes, I highly doubt that anyone is going to "take a bath" on a 4.5k amp when upgrading to one 4 times the price. I don't see the relevance of your post nor understand your point. Used Bernings don't seem to hang around on the market long. Berning's reputation seems to have been built on word of mouth more than marketing hype. Maybe another reason for the relative obscurity of his products to most audiophiles. His approach appears more 'take it or leave it". He doesn't need to push his products and if you weren't aware, has been around much longer than most of the other well known hi-end manufacturers with very few exceptions. The reason? low overhead and product acceptance. The guy hand makes each amp in his home. Now that's what I call sticking to basics.
Jtinn, thank you for your comments. As I mentioned in my last post I apologized for any offense that may have been taken, and said that I am not accusing you directly of doing the bad stuff that is common in the industry, as I have no basis for such. Just for the record, I am not the person that made the comments comparing the amps in different systems.That was Kris, not me. I just made a conjecture on what I thought would be the result of the comparison. From what others have said here on the forum, you are a good guy and have been helpful to others, so I defer my pointed remarks. However, the industry in general is most deserving of those pointed remarks, and I think that it has injured the hobby with its much less-than-pure approach towards its customers. I am now sorry that I included you in that group, in light of what I have now learned. Enjoy those Tenors and perhaps, one day, I'll even have the chance to try some in my system. Happy listening!
twl, you're right, you didn't get the point. Or the relevence. BTW, classy reply to jtinn.
Mes, your point was misconstrued by Tubegroover, not me. I understood your point perfectly and thanks for your comments on my post and on the thread.
could somebody recommend a good home Theatre speaker for use with the Berning 270 amplifier?