preamp gain in relation to whole systems help

Hi Al

i am not sure bout gain stuff as well. maybe its 2^(2-1)=2db and 2^(8-1)=64db? can someone correct me if i am wrong.

how bout using 24 stepped attenuator and alter the resistors? say use 100 stepped calculation for 100k pot but only use the first 24 steps? will this help with the volume adjustment? thx for the helps

No, I doubt that is the correct interpretation. Just about any preamp other than a passive one will have considerably more gain than 2 db, and no line-level preamp will have anywhere near 64 db gain (although with a phono stage included that is somewhat in the right ballpark). Also, 62 db gain difference would make more difference than 8 o'clock vs. 11 o'clock on the volume control, I would think.

Changing all those resistors sounds like an awful lot of work, and might cause you to lose the proper logarithmic taper. You WANT the steps down near the bottom of the control range to be larger than the ones near the middle, so that you can reduce the volume to zero and near zero values. And you want the steps near the middle of the range to be small, to allow fine volume adjustments.

A simple solution for the gain of 8 preamp might be to put an in-line 10db pad (fixed attenutor) in series between the preamp and power amp. Look at the specs for preamp maximum output voltage and power amp input voltage or sensitivity to see if that would make sense.

Regards,
-- Al

This attenuator has been recommended by some others here at Audiogon in previous threads:

http://www.rothwellelectronics.co.uk/html/attenuators.html

Regards,
-- Al