300B SET Amp driving Wilson Sabrinas


Interesting experience to share.

In my home system I have a pair of Wilson Sabrina speakers normally driven by a Modwright KWA 150SE (Special Edition). On a lark, I replaced the Modwright with an Elekit 8600S 300B amp (Lundahl output transformers and Mundorf Supreme output capacitors) I had in another system.

The surprise, not only did the Elekit drive the Sabrinas very well (improved clarity and tonality), but at the same volume with the same input level as the Modwright! Using a passive preamp, when I set the volume knob on the preamp to the same point for both the Modwright and the Elekit it results in essentially the same volume from the speakers.

Admittedly I listen at moderate levels (SPL rarely exceeds 70dBA), but the sensitivity of the Sabrinas is only 88 dB. Who would have thought!!

 

gareents

No surprise at all. Now, turn it up and see what happens. IMHO music should be listen to at realistic levels, but kept below ear damage levels. Many people listen quietly for a number of reasons and might get away with a SET amp. If you really want to hear what glorious sounds like, put a Pass XA 200.8 in there. Any thoughts of set amps will immediately dissipate, even at low volumes.

👍

Pairing of low powered tube amps can be incredibly informative. First that speakers are far less sensitive to tube amp power… way more than you would think. You put a low power solid state amp in there like a Pass kit and it would sound dead and completely underpowered. Also, the midrange produced by a 300b tube amp can be pretty intoxicating. I had done this recently.

 

My ARC tube amp can be run in triode mode 70wpc or linear, 140wpc. Virtually no difference in volume or dynamics (my speakers 90db efficient).

@mijostyn +1. Pass XA200… or even better an ARC 160 amp.

The volume control being at the same position means nothing really. It only means that the two amps have similar gain and input sensitivity. If you had increased the listening level, the shortcoming of the SET amp would have been easily noticed.

@mijostyn +1: A 7 watt SET amp has a really limited dynamic range unless you have Klipschorns (100db sensitivity). To hear an appreciable increase in loudness with the Sabrina's an amplifier of at least 70wpc is required. 10 x the wpc = twice the perceived loudness.