I agree that most of us can hear only up to perhaps 15kHz but higher system bandwidth guarantees low phase shift. For instance my Rowland 102 amp has -3dB bandwidth of 65kHz but at 15kHz has phase shift of about -20 degree. Even at 10kHz it is still around -15deg. This phase shift affects sound (summing of harmonics). I would feel more comfortable with at least 100kHz bandwidth but agree with Al that bandwidth too high has problems of its own. Obvious problem is HF noise pickup but less obvious is increased chance of Transient Intermodulation (TIM) since reduction of the bandwidth at the input reduces TIM.
Bandwidth question?
I am interested in the qualitative difference in sound betw amplifiers that have -3db roll off at 100khz vs -3db at 300khz. Thru the amps I have tried, I suspect increased bandwidth has more openness and transparency and hence a better sense of space sharing. At the same time, it is easier to screw up the sound due to noise (from components/AC/RF) or improper cartridge loading. I am not very certain of the correlation and interested in what you guys think?
In reviewing the measurement sections of stereophile, many amps with -3db at 100khz demonstrate subtle rounding of the edges when reproducing 10khz square waves. I don't listen to square wave so I don't know what that translate into.
I realize that some amps (Spectral or Soulutions) has very high bandwidth (MegaHz) to implement negative feedabck. I am not refering to that.
In reviewing the measurement sections of stereophile, many amps with -3db at 100khz demonstrate subtle rounding of the edges when reproducing 10khz square waves. I don't listen to square wave so I don't know what that translate into.
I realize that some amps (Spectral or Soulutions) has very high bandwidth (MegaHz) to implement negative feedabck. I am not refering to that.