SET vs PSET

Yes, no phase splitting, but as Charles1dad mentioned, there is the issue of one tube ending up doing most of the work. I know of an amp builder/designer who mentioned how hard it was for him to get PSETs to work because of this problem. But, he did hear the PSET amp I own (Audionote Kageki) in my system and agreed that it sounded very good.

The purists don't like PSET because they believe that the more tubes that as you pass the signal through more tubes, even in parallel, the sound becomes muddier. This is the same objection raised with high power pushpull amps that have multiple output tubes.

On the plus side, at least theoretically, the output impedance of the tubes operating in parallel is halved, meaning that the either the amp output impedance will also be lower or the designer can use a smaller turn ratio in the output tube (generally considered desirable).

Theory aside, I have heard plenty of good SETs, PSETs, pushpull and OTL amps so I have don't really care about the design approach taken.

Thank you all for the replies .

Larryi ;
"I have heard plenty of good SETs, PSETs, pushpull and OTL amps so I have don't really care about the design approach taken."

Could you give me a list please , especially the PSETs ?
PM me if you wish .

Some well regarded examples of PSET,
Audion Audio,
Absolare,
Border Patrol,
AN UK and AN Kits,
Purity Audio,
Wyetech Audio,
These cover a broad price range spectrum.

I knew I could count on you guys! Thanks, Kenny

Saki70,

The PSETs I have heard included the Audionote Kageki (the one I own), Audionote Gaku-On and Sogon. I have also heard two custom-built amps, one a 300B amp the other a 45 amp. All of them sounded really good.

I have heard quite a few SET amps, e.g., Audion, Wavelength, Art Audio and a lot of custom/home built amps. I particularly liked the 211 amp built by Wyetech and a 845 (I believe) by Viva.

I own two pushpull amps that I like very much. One is a custom amp that uses two 45 tubes per channel. The amp that I currently run in my system (the Kageki is on loan to a friend) is a cutom rebuild of a Western Electric 133 amp. This amp uses 348 driver tubes and 349 output tubes (a whopping 5 watts/channel). As compared to the Kageki, the 133 has tighter, punchier bass, and an even more beautiful midrange. The tradeoff is that, like most pushpull amps, that tighter and "punchier" bass sounds a little mechanical and has a sameness no matter what is being played, while the Kageki is more varied and "tuneful" in its bass presentation. The Kageki is also a bit more open and extended sounding it the top end. Like everything else in audio, tradeoffs are involved. A local dealer owns a Western Electric 59A amp (252a tube) that sounds REALLY good, but that amp carries a CRAZY price. This is the best pushpull amp I've heard.

The commercial OTLs I have heard, and like, include models from Atmashphere, Joule and S.A.P. The Atmasphere has, in comparison to the Joule and S.A.P., a leaner sound. Which would work best, is a matter of taste and system matching. All of these amps deliver a very immediate, lively sound that I find VERY appealing (some high power pushpulls deliver some of that kind of punch, but almost always with an unpleasantly hard and artificially edgy quality). The very best OTLs I've heard were built by a Greek hobbyist (he made somewhere around ten amps). The two version I heard were unbelievably dynamic, yet smooth and utterly musical--up there with the 59A as best amps I've heard.