Low noise.
And the most significant factor in getting this is using specially manufactured low noise transistors at the VAS stage of the amplifier.
Of secondary importance is to have very well shielded cables, maybe a ground lifter and no ground loops.
And the most significant factor in getting this is using specially manufactured low noise transistors at the VAS stage of the amplifier.
Of secondary importance is to have very well shielded cables, maybe a ground lifter and no ground loops.