Wouldn't a missing weight in low register be a clear sign of an impedance mismatch between the source and the power amp?
I have a DAC with 2.8k output impedance and I'm very reluctant using non-bufferred passive preamp. Is there a trick (lamination maybe) how to sort this out with Slagle AVCs?
ok... 2.8k is on the high side for what is out there on the market... but I bet it will be just fine.. I know John doesn't want me to post this, but you can get them stacked 1x1 for extreme applications... the formula for low frequency rolloof is:
impedance/(2*Pi*inductance) = -3dB frequency...
my memory is fading, I think John's stacking spec is 100 henries... 6x6... so that would be -3dB at 4.5Hz.. -1dB at 9Hz... plenty for me... don't forget this is in parallel with the input impedance of the amplifier reflected through the volume step's ratio... so it really only changes things if you listen to the top three "clicks"...
hope that helps?
so the numbers posted of 100 ohms feeding the 30k ohm amp through the autoformer certainly meet even the high criterion of 10:1 source to load...
oh.. and I have noticed them sounding slightly thin when new.. not sure why, but it is there...
Peace,
Me