SET Preamps

Not sure how you are defining "SET preamp," but as I would define it most and perhaps nearly all tube preamps are SETs.

Meaning that their output tubes (and other tubes that are in the signal path) are triodes, and the output stages do NOT consist of two triodes, or two triode sections, operated as push-pull pairs. Push-pull, btw, is NOT the same thing as differentially balanced, in case that is not clear.

The phrase "SET" is normally used to distinguish power amplifier output stages that consist of triodes that are not operated push-pull (and which usually provide very low power capability), from other output stage topologies that are operated push-pull and/or are based on tetrodes or pentodes.

Regards,
-- Al

Of course, Al the whole thing is ridiculous. Virtually all preamps are SET. The exception being preamps that use tubes that are combo pentode/triode tubes like the 6U8, 6AN8, etc, and these are as rare as hen's teeth. In fact, one might even call these SET as SET amps that use pentode drivers and SET output stages are still referred to as SET. It would be much harder to name preamps that are not SET, but the Shindo models come to mind as using pentode stages before the final output.

A triode is a triode.

Perhaps you meant to enquire of Directly Heated Triode preamps, a less common kettle of particularly tasty fish...?

We make some of the very few tube preamps that are **not** SET... ye olde Dynaco PAS-3 is SET, as is the Citation 1, many of the earlier ARC preamps, the CAT, the Joule Electra; Al is correct- most tube preamps are 'SET'. The term really is for *amplifiers*, where it creates a distinction, not preamps.