Why do amps sound different?


Hi folks, can anyone tell me why amps sound different? I know this is a very trivial question, but it isn't so trivial as I previously thought. For example: an amp can sound "warm", while the other can sound "lean" and a bit "cooler". These amps measure the same on the test bench, but why do they sound different? What causes the "warm" characteristic if the amp has pretty good measurements and frequency characteristics? It is certainly not measurable high frequency roll off, otherwise the amp sucks. Maybe one of the experts among us can elucidate this issue a bit. Thank you.

Chris
dazzdax

Showing 2 responses by shadorne

Generally if there is an audible difference then a difference can be measured. Specifications are however measured under conditions that are not typical of when a power amplifier is used to drive a complex load (speaker).....hence the possibility for different sound. In general, good pre-amps should sound exactly the same - if they sound different then one may be suspect or there is a mismatch between rated input and output levels and/or impedance with other connected components. Often a distinguishing feature between a good preamp and an excellent one is better channel separation, immunity to noise (from dirty power) and lower noise floor.

Note that the other way round is not true....often a difference can be measured that is inaudible when listening to music.
Kurt,

I like your wine example. In amplifiers, it is TIM, IMD and high order odd harmonics that can make it sound "corked" even if the distortion levels are extremely small - would you agree?

Perhaps there are other "contaminants" that in extremely small doses can affect the sound audibly...what "contaminants" do you look for?