SET for 88 dB 4 ohm loadspeaker

>Won't work. You need push/pull tube. Either KT90 or 6550<

No, that is bad information. An SET amp such as the NAT Se2Se will drive that load without breaking a sweat. These amps are push pull SET, Class A, and output 70WPC into a 4 or 8 ohm load.

I have no affiliation with NAT.

Audiofeil, I don't think you can have a push-pull SET. Do you mean push pull with a triode tube (e.g. 300b)?

Pawlowski,
I meant SE push pull.

My typing got in front of my brain.

My bad.

Sorry.

Audiofeil,

One of us is confused here. What do you mean by SE push pull? Aren't the two designs, single-ended and pushpull inherently different? Single-ended means that one tube (or set of tubes in parallel) reproduces both halves of the wave form (by modulating DC current flowing in the primary). Pushpull means that tubes reproducing the opposite halves of the wave are connected to the opposite ends of the primary, with the DC voltage at the center tap.

I don't know anything about the amp you mentioned, but it could be a triode, class A, pushpull amp. But I don't see how it could also be single-ended.