[jtwrace]

to explore OTL amps.

Which ones though?  The David Berning amps are very expensive from what I remember.  Atma-Sphere?  Transcendent?????

[Quiet Earth]

Good point, you got me there. Maybe someone can help me out. We would have to compare apples to apples in terms of wattage and quality level I think. I wouldn't have a clue where to begin.

 I do understand the desire to bypass the transformer thinking that it is an obstacle instead of an asset. It seems like with OTL designs you are trading one set of problems for another. As a consumer, I don't like the idea of having to use so many power tubes when I can just use one through a really good o/p transformer. But there are probably good reasons for using OTL so I'm not putting them down.

I don't think that saying all transformers are flawed is correct either. The transformer is a really cool device in my opinion.

[OzarkTom]

Which ones though?  The David Berning amps are very expensive from what I remember.  Atma-Sphere?  Transcendent?????

If you win the lottery, buy the Berning mono blocks. Until then, buy a pair of Futterman H3AA's. Originally built in 1977, no tube amp with transformers will ever beat them if you have efficient speakers.

I was searching the net tonight and found this read from Harvey Rosenberg. Nobody on this planet knew more about OTL's than this guy did.

http://www.meta-gizmo.net/futtrmn/intro-futtrmn.html

[OzarkTom]

A pair of Atmasphere 60 watt mono blocks went for $1650 for the pair today on Audiogon. That would have been a good buy.

[Rob Babcock]

I think people believe whatever helps get 'em through the night.  This is just audio gear, people...it ain't life or death.  There's plenty of room for all types of gear and all belief systems.

[JerryM]

I think people believe whatever helps get 'em through the night.  This is just audio gear, people...it ain't life or death.  There's plenty of room for all types of gear and all belief systems.

Hear, hear! 

It's all about the music.

[OzarkTom]

Hear, hear! 

It's all about the music.
[/quote]

Yup, and that is where the OTL's reign supreme. Listen to at least one in your lifetime.

[Quiet Earth]

If I ever get a chance to hear one I will make the effort Tom. The little Berning had always caught my eye in the past but I never got around to hearing it. I don't see a lot of OTL in my area but I'll keep my eyes open.

Welcome to AudioCircle. 

[drphoto]

I sort of think the speakers make a much bigger impact on the final sound than the amps, as long as the amps are at least of reasonable quality and are matched to the the given speaker. Agree that there are good and bad example of both SS and tube.

Oh....and don't forget about about the room. Room treatments can be huge in the final equation. In my system the upper mids sounded a bit harsh, and I kept thinking TUBE preamp! However, more GIK panels, specifically on the ceiling really helped. Even w/ a custom fabric, they're a fairly inexpensive upgrade.

So I would say tubes don't equal better...or worse. I should be a politician! But opinions are like you know what.....we've all got one.

That being said, I'd love to hear an OTL amp. I know Bobby P. the maker or my Merlins shows his product only w/ OTL amps. Joule-Electra I think.

[Tyson]

Tubes or SS?  How can you all hear the difference through those crappy passive parts in your speakers' crossovers   Go active and you'll hear what a good tube amp can REALLY do

[DaveC113]

That being said, I'd love to hear an OTL amp. I know Bobby P. the maker or my Merlins shows his product only w/ OTL amps. Joule-Electra I think.

I've heard his room the last 3 years at RMAF. It's always one of the best there, IMO. I could see trading in my SET / Single Drivers for it, but it's A LOT more cash than I have into my system.

[Wind Chaser]

I don't have a bucket list yet, but when I do, hearing music through an OTL will be on it.

[Niteshade]

Here is something to be interested in: Circlotrons!

http://circlotron.tripod.com/

Nobody ever talks about it and I believe such a topology is a good compromise between OTL and standard output transformer systems.

[jtwrace]

Blair,

Are you going to build some OTL's?

[Niteshade]

I honestly do not like the OTL philosophy. It's too inefficient.  A circlotron uses a bipolar power supply like an OTL and depends on a balanced signal output from the power tubes with no DC offset. No DC through the output transformer primary can have a dramatic positive effect on performance.  As it is, it's important to reduce DC idle current through standard configurations to increase performance. I firmly believe that a circlotron is the next level up from standard configurations and not OTL's based on the technological qualities of the circuit, one being mentioned above. You get a performance boost AND remain efficient! What more could one want? A side benefit is the amp won't look like a pinball machine. 

A circlotron based amp is going to be looked into. That's for certain!

Blair,

Are you going to build some OTL's?

[Quiet Earth]

Cirlotron, cool . . . . just saying circlotron sounds retro-cool. 

What more could one want?

In order of importance
1. Reliability
2. Ability to drive a normal speaker
3. Sound quality

My recollection of OTLs is that they spent a lot of time getting repaired. I could be way off on this. (Old data?)

[chosenhandle]

if you want to learn more about OTL and circlotron circuits, you may want to visit the Atma-sphere website where there are a number of white papers on the subject.

Disclaimer: I own all Atma-sphere gear, so I am biased (like my amps).

http://atma-sphere.com/papers/otl.html

[jtwrace]

Disclaimer:  I am biased (like my amps).

 

[pjanda1]

I think the point is that tubes are not the end all be all.  I've heard tube gear that I wouldn't own, even if it was free, and I've also heard some tube gear that was outstanding.   There are many naive people who think tubes are universally better than SS.  Not so.  Not even close.

This post may strike near the heart of the truth: amp topology probably matters more than the type of devices used to do the amplifying.  There was a time when tube amps tended to be similar to one another, as did SS amps.  But now, you can get single ended, low parts count SS with no negative feedback (see First Watt or Ayre Acoustics), and you can also buy giant tube amps running all sorts of pentodes with a bunch of gNFB wrapped around them.  If you compared the two, I'm positive that many listeners would hear a difference, and they'd think the SS was tubes and vice versa.

Tubes are, in general, more linear amplifiers than transistors.  So, it is easy to implement them in simple designs with low or no feedback.  But that doesn't mean that you can categorically say there is a tube sound, and an SS sound.  Different amplifiers sound different, and that difference depends on all sorts of things.  Be glad we live in a time and place where we have more variety than ever, at price points for everybody and if not complete agreement, a better understanding of why things sound the way they do.

I build tube stuff.  If I had the time and $$, I'd love to DIY a First Watt J2 to compare a giant class A, SE ended JFet to my favorite simple little tube amp (which has a solid state rectification and transistors as a constant current source to the driver tubes).

Paul

[Niteshade]

Couldn't agree more. 

Actually, a circlotron should be able to handle a wider array of speakers than a basic OTL. That's the beauty of output transformers: The uncanny ability to properly match an amplifier up with a load and do it efficiently. Circlotron transformers are different than mainstream outputs...actually MUCH better! The primary & secondary turns ratio is much closer. The lower impedance guarantees great performance.

Cirlotron, cool . . . . just saying circlotron sounds retro-cool. 


In order of importance
1. Reliability
2. Ability to drive a normal speaker
3. Sound quality

My recollection of OTLs is that they spent a lot of time getting repaired. I could be way off on this. (Old data?)