Myth: low-power high-efficiency


The past 6 - 8 months I have been living with very efficient speakers (~ 109dB/m/w) driven by low-power SET amps. The amps use 300B output tubes for about 7 wpc. On paper, this should be a match made in heaven. In fact, the combination is capable of wonderful nuance, subtley, harmonic richness, and tonality. It is really pleasing, especially on chamber and jazz music. Except for one thing - dynamic energy. I am not referring to loudness. It can deliver more undistorted volume than I care to listen to. I'm referring to immediacy, presence, power, and punch - the life of the music. If you go to the symphony, or live blues, than you know what I am talking about. Next week I'm taking delivery of a 90wpc PP amp, to audition in place of the SET. I need an amp that can maintain the purity of tone and harmonic texture of the SET, while delivering more power, to grab hold and take control the 15" bass driver in my horns.

I searched the archives, but have not found a similar post. Are there any other high-efficiency low-power people who moved to a higher power amp? Are you satisfied now?

Scott
skushino

Showing 1 response by david12

I agree, a fascinating thread and a subject I have been struggling with. I discussed the power issue with Kevin Scott here in the UK, he makes the well regarded Living Voice Speakers, a range built with tubes in mind and with about 94db sensitivity. I was contemplating the Welborne lab monoblocks and Kevin said, they would be great, but limited to small scale music, Jazz combos, solo singers. It is not simply a question of rock, large scale Classical and opera chorus's put similar demands on a systems abilty to cope with dynamic swings.
The conclusion, 7 watts good, 18 to 22 watts of SET power much better. I also concur with looking at 45/845 tubes rather than 300B's, for the frequency extremes. The problem of course, is that good 20watt SET's with adequate transformers, aint cheap. I was lucky to find an ex dem Viva Solista from the audio pimp on the Gon(strongly recommended by the way) for "only"! $3500 new its $9000. It is an 18watt 845 SET and I am pefectly happy, real drive and dynamics, even on compex congested passages. Unfortunately I had to go for a Lavardin IT integrated for warm weather use, equally wonderful, but quite different.
Those 2 amps will keep me happy for the forseeable future. The next temptation is the new range of high sensitivity compression horn speakers Tyler Acoustics is bringing out. When will it all end?