Bennett Prescott wrote on Sat, 23 December 2006 11:33 |
I suspect that differences in timbre between mic preamps is one of those things, like differences in sound between two perfectly flat speakers that nonetheless sound different, that cannot (easily?) be measured in Smaart. No doubt there is a phase component, but the rest... who knows?
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Arghhh... "Timbre"? While I suspect real differences between preamp are overstated, if there are repeatable audible differences they can be characterized by measurements. Note: I am not saying that they are characterized by published measurements only that they can be.
To fully characterize a mic preamp one would need amplitude, phase, linearity, noise, and input impedance plots... for every gain setting. If there's a pad, that must be characterized for how it impacts input impedance and other performance measures.
We seem quick to forget these are connected to microphones which are not only far less accurate, may also exhibit dependencies on input termination.
Not to mention perceptual biases caused by gain law, feel of controls, brand halo effect, and dirty tricks. For example one trick I've seen (I will not publicly out the brand but I doubt it was accidental) was to under size the blocking cap in the gain pot leg. This had the effect of a sliding HPF that dramatically reduced 1/F and LF grunge from the preamps noise floor at max gain... "Man just listen to how quiet these preamps are compared to (a flat) brand XYZ". Of course published frequency response was measured at a modest gain where it exhibited decent bass response (coincidence, I think not).
Merry Christmas folks...
JR