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 tubes108

Hey Scott. I have a speaker rated at 103 db. At least based on experience with my system, a high powered amp was not required to achieve the “dynamic energy” you refer to. I’ve gone from a high powered amp to a small SET amp. The first amp I used was a 160 watt OTL amp. A fantastic amp, but not the best match for my speakers as I was limited to use of 2 or 3 clicks total with my preamp’s volume control. I’ve tried some low powered amps with unsatisfactory results, until I used Art Audio’s PX-25, 6 watt stereo amp with fantastic results. Though, they really shined in the “dynamic energy” department after I inserted the new power cords and cables from Basis Audio. Note, that my subwoofers are powered by an amp driven by the output of the Art Audio; thus your mileage may differ.

I am unfamiliar with your speakers and associated gear. If others that have some of these components can achieve this dynamic energy, then I’d think it is not a component issue, it is a synergy issue. Certainly explore the use of other components with your speakers. But I would not limit this to say looking only at higher powered amps. In fact, like my OTLs, the sensitivity of some higher powered amps may make their use impractical with your speakers. Also, you may want to explore other cables/power cords, etc. I was shocked that changes in these products did significantly more than what I expected, which was a best a slight shift in various sonic attributes.