living sounds
Well-known member
Following suggestions from very helpfull and knowledgeable forum members I've lowered THD in my console signal path from channel line input to master output to essentially my soundcard's level (first harmonics visible for a 1k sinewave start ca. 110db below signal peak), via heavy local decoupling and building a "dirt ground".
Sounds great, but now I've discovered that switching the VU meter to display the output signal results is raising THD by a considerable amount. This does also happen when the meter gets fed the PFL signal.
I should also mention that all signal path caps have been bridged, excluding the inaudible ones like those going to the meter, of course. The 2uf caps before the meter have been replaced with 4,7uf.
All caps, including the TL074 driving the meter are bypassed locally via three 10uf electrolytics (+/- to ground and rail-to-rail) as well as a rail-to-rail 100nf ceramic. Decoupling the TL074 didn't make a difference though.
Any ideas how to fix this? Thanks!
Sounds great, but now I've discovered that switching the VU meter to display the output signal results is raising THD by a considerable amount. This does also happen when the meter gets fed the PFL signal.
I should also mention that all signal path caps have been bridged, excluding the inaudible ones like those going to the meter, of course. The 2uf caps before the meter have been replaced with 4,7uf.
All caps, including the TL074 driving the meter are bypassed locally via three 10uf electrolytics (+/- to ground and rail-to-rail) as well as a rail-to-rail 100nf ceramic. Decoupling the TL074 didn't make a difference though.
Any ideas how to fix this? Thanks!