03-17-14: Unsound "...200wpc SET amp..."? What amp might that be? This one (there's another like it for the right channel): The Midlife Crisis |
Al, Ralph......we are all waiting. Try to be as accurate as Unsound was please. ;^) If we actually graphed the amplifier's distortion response when subjected to a standardized non-repetitive waveform, we could probably put numbers to that. Until then its a subjective experiment. I can tell you this- if distortion is present it can cause the sound to seem considerably louder than one might expect. So given two amps, one lacking distortion and the other with distortion, the more distorted one is likely to sound considerably louder. You know how SETs, when reviewed, frequently have the comment (paraphrasing):'...this amp sounded considerably more dynamic than it had any business being on account of its low power...' ? This is entirely due to the distortion of the amp, which is unmeasurable at lower power levels. But if the power goes over about 20-25% of full power, the higher ordered harmonics come into play, which are likely only on the transients of the music. So you have the loudness cues on the transients and considerably lower distortion in between- the result will be that the amp sounds really dynamic. But its actually an interaction between how we perceive sound and the behavior of the electronics. So to answer the question, I would say it depends on the amp and to no small degree the load (which must be benign). But the tube amps may seem to have anywhere from a 3 to 6 db advantage over transistor amps (of the same power) in this regard, depending on the topology of the amp. I can break that down further- SETs will be more likely to seem to behave as if they have a lot more power, followed by push-pull triode amps. On the other end of the scale, a push-pull pentode amp employing feedback will seem to have the least 'overhead' in this regard, as they will have a sharper clipping onset. The better tube amps will often seem to compress slightly before outright clipping occurs. This has a lot to do with improved power supplies, as a robust supply will reduce IMD in the amp. |
