OTL or SET? Differences?


With my limited knowledge, I know that OTL is transformerless and SET is single-ended. But what are the main advantages and disadvantages of these two designs? How to choose matching speakers for these two different designs?

Currently I have an Atma-Sphere OTL amplifier.

Thanks in advance!

Otto
yu11375
Hello Otto...Greetings from Australia !!!
I have tried several good Amplifiers on the Horning Alkibiades 99db,which have very deep bass and the appropiate big enclosure...Rushtons ,comments of the Atma-sphere S30 are spot on "On the flip side, the Atma-Sphere OTLs will be very neutral, very detailed, highly resolving -- in the words of a listening partner here: pristing like a clear glass onto the music. They won't make the music more beautiful, you'll simply get what's coming from your front-end source without editorial."
The Tom Evans "Soul S15" SET Cass A falls somewhere in between my current amplifier,the KR Audio Stereo Kronzilla and the Atma-sphere...The "Soul" controlled the bass on the Hornings better and being a KT88 valve,you could tweak the sound a bit...I would say it was a bit more involving,but it needed a active pre-amp ,where the Atm-sphere and KR are happy with a passive...the KR Audio Kronzilla was in another league...also many would argue that it is not a "true" Set amplifier ,as it uses,like the "Soul",a SS front end...the Kronzilla simply was a step above all of the amplifiers I have heard in control,air and musicality...the PRAT is just great...the only amplifier ,I reckon would compete ,would be the VAC or Canary 300B push/pull...hope this helps...
Regards
Helmut
FWIW, one thing that OTLs and SETs have in common is that neither has any hysteresis loss in the output transformer.

SETs do not reverse the magnetic field in the transformer, and OTLs don't by definition.

Removing the transformer also removes the argument against push-pull. You don't have hysteresis loss, so you don't get the attendant loss of detail that is an effect hysteresis loss. This means that push pull need not be a 'sin' as mentioned above.

Of course our stuff is all-triode too.

Hysteresis loss is the property of magnetic devices wherein it takes a little bit of energy to reverse the magnetic field in the device. In the case of output transformers, this energy comes from the signal and is responsible for a loss of low level detail and an attendant increase in low signal distortion.

Duke, sorry to hear you are having worries. So far in the years I've been on this forum, no-one has challenged me in the way you mention. For that matter I've not had any posts that could not be approved (that I remember anyway...), but I try to be really careful not to cross the line. Too much:)
Excellent post Rushton, I completely agree with your comments, especially with reference to full range music and the typical listening impressions when listening through OTL vs SET, its true, its true.
Tubegroover, thanks.

Audiokinesis/Duke, you're consistently one of the most balanced and helpful people posting on Audiogon. I'm amazed someone has made a point of attacking you; that's unconscionable. Thanks for all that you've added here over the years, and I hope the nonsense doesn't put you off.

Ralph, I've never heard that hysterisis loss explanaton before. Thank you.
Of course those of us who have been paying attention are well aware of his tt/arm/cart/preamp/amp/spekers. Time to post pictures?