SET vs PSET

This is an often discussed point for those in the SET world.Some will say the problem with PSET is getting both tubes to work in an identical manner. They say one tube does more than the other (they don't stay in a equal balanced harmony). Others strongly dispute this claim and say "proper" design and execution overcomes this problem. I tend to lean toward the latter camp and believe good implementation is the key for successful PSET amplfiers. I use a single tube(SET) but I don't need the additional power PSET provides. If added power isn't required, a single output tube is nice and simple.
Charles,

To me, the issue may even be a bit more complicated. While I agree with Charles that proper implementation may help to overcome the theoretical disadvantages of PSET, it is likely to be more expensive. As a result, if one does not need increased power, then SET makes the most send. However, if one DOES need increased power, then the other comparison is PSET using lower power tubes (300b, 2a3, 45) versus SET using higher power tubes (845, 211, EL34).

Hi Kennythekey,

"the signal path being split apart and then reassembled" is a description of how a push-pull amp works.
PSET amp does not split the signal, the driver tube simply drives the two output tubes via a capacitor or interstage transformer and those two tubes output are combined into the output transformer.
Jet

Jet,
You are right, Kenny describes what happens to the signal (phase splitting) with a push pull circuit I believe. The stated advantage of SET/PSET is the absence of signal splitting.

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.