Which Aleph To Go?

[Jay]

Hi,

I want to optimize my system in the following arrangement: Burr Brown OPA 2134 à level shifting stage à IRF9610 differential stage à IRFP250 output à 88dB speaker.

Firstly, what I need is the right Aleph version to choose. Still a big question to me is how Aleph 3 differs in input circuitry (and feedback) than the other Alephs. I don’t know the effect of this difference on the output signature.

The input impedance of Aleph3 is about 22K and other Alephs (?) is about 10K. What I think I need is a higher input impedance (and a higher damping factor). As I currently using Aleph3, I need to know the effect of migrating to other Alephs, especially if I use different resistor values to increase input impedance (whether it will get better or worse).

Question#2, I guest the paralleled 100K and 10K in input circuitry of Aleph5 is the result of software optimization. Otherwise I’m completely lost as of why it is not better be replaced with a single resistor.

Question#3, If I had 4 matched pairs of output MOSFET, and 1 or 2 pairs in say 0.3V deviation. Will I better use only the 4 pairs?