HiCap-powered sounds right - not 'OTT' at all! I'm sure a SuperCap would make your 12s-5 sound even better!
Andy
I have ordered a blue alps 20k. Do I wire the leads the same place as on the original pot?
Can anyone suggest a simple way to reduce the overall gain on a NAC12S driving a NAP 120?
My setup is in a small room and I have Videoton Minimax speakers and am quite close to the speakers. The volume control is nearly always between 8 o'clock and 10 o'clock!
I have and attenuated lead for the CD but even on the LP12 the volume control is too sensitive.
Ryan Sound Labs probably out of my budget but thanks for the suggestions.There is such a mod - and I read about it here. Neil McBride is the name of the guy who posted it; he has a website.
Or, buy the Ryan Sound Labs replacement daughter-boards ... these have (I think) 3 different gains that you can set using jumpers. They are also supposed to sound considerably better than the Naim boards - I can't confirm this yet, though, as I have bought the boards but haven't yet installed them.
Regards,
Andy
Output board gain can be altered by changing the amount of feedback, which is set by the value of two resistors. As standard the values are R9=1K and R14=12K, which sets the gain at 13 (R9 + R14 / R9). This translates to 1V output for 75mV input. To change the gain you need only change the value of R14. Changing R14 to 5.6K halves the gain.
Mr Tibbs
Thanks for the tip. OK, changing R14 from the stock 12K to 5K6 halves the gain ... does this produce more feedback (to go with the lower gain) ... or less feedback?
Thanks,
Andy
Yes; feedback doubled = gain halved.
Side benefit of increasing feedback is improved performance (measurably lower distortion and flatter frequency response).
Pitfall of increasing feedback is greater risk of instability so don't be tempted to go too far.
Mr Tibbs
Thanks, Mr T. But another pitfall of increased feedback (associated with lower distortion) might well be a change in the harmonic profile to reduce H2/H3 and increase H5 and above? Which will tend to make the sound harsher.
Andy
We're talking going from very low THD to lower still. Highly unlikely there would be any difference subjectively.
Mr Tibbs
I still use a serviced Nac 12S in original condition, right now with a recapped Nap 120. The latter is superb, a fantastic power amplifier.