SET Amp question


I'm interested if anybody has experience using a SET amp with certain harder to drive speakers, like the Dynaudios and OHMs in my system, or others. What might one expect from such a combo sound wise? Could it work well say in a smaller bedroom system that will not be played too loudly in general.
128x128mapman
Friend

Think of it this way:

The SET Amplifier is like a singer / vocalist without a microphone, and the Loudspeaker is like a space or venue in which the singer / vocalist is singing.

In a modest sized venue - the sound will be sweet because the performer can sing at their singing volume and everyone can enjoy. However, if the venue is too big - the performer has to try to sing louder - affecting tone and still not fulfilling the desired performance.

So, what you will have is a SET Amplifier that is not giving you 100% SET sound. It will be best if budget permits to get a compatible Loudspeaker.
Depends in part on the amp's output impedance and the speaker's input impedance.

Oversimplifiying a bit, a high output impedance (low damping factor) amp will put out increased power into an impedance peak, and decreased power into an impedance dip. In contrast, a typical solid-state amp will have the opposite characteristic.

So if the speaker was "voiced" on a solid state amp, and its impedance curve has significant peaks or dips, the resulting tonal balance will probably be quite a bit different on a typical SET amp, regardless of whether the amp has enough power to drive the speaker to satisfying levels. For example if your solid-state-voiced speaker has an impedance peak at 3 kHz, it will probably sound too bright and forward with a SET or OTL amp - and you would be mistaken to lay the blame on the amplifier, as the cause would be poor synergy.

Duke
dealer/manufacturer
Nothing good (unless you go to higher output tubes).

The Verity Parsifal/Encore is a modestly difficult load and it swallowed my Cary 300B monos whole. OTOH, the Cary 805s work just fine with the P/Es. Never even thought to try the 300Bs with my Ohm 100s (which seem to like more, more, more when it comes to amplifier muscle). I'd bet that the 805s would work, but I wouldn't expect improvement over the ARC VT130SE I'm now using, so I'm not about to schlep the 805s into the listening room in anticipation of degraded results.

The problem is that -FOR THE TRUE BELIEVER SET GUY- the low powered amps are the only true key to a happpy life. Flea powered designs just won't work in the type of application you describe and even 300Bs IME will struggle. You're left with the 211/845 designs which will probably provide decent results, but:

A) won't sound their best in such a pairing,
and
B) may not be "SET" enough to satisfy the experiment.

Just my experience.
Good Luck.

Marty
The Cary 805 AEs are honestly hard to fault in comparison to even the best SET amps (which to me are 45s). I never did any sort of A/Bing because you wouldn't use the two on the same speakers - but the AEs are no slouches in any department.

To get a hi-power SET (anything stronger than a 300B) to sound really good takes a great deal of money in the power supply and output trannies. There are no good, cheap 211 or 845 SETs. Not really good anyway. The bargain gear does still give some SET sound but will be slow and rolled-off due to the inevitable bandwidth restrictions.