So now that my Copper is up and running, flawlessly might I add, I found some issues with my Bronze pre. Although at first it seemed to be fine I noticed some small issues.
1) When the DI is engaged, there is a high pitch ringing noise, and an intermittent chirp/squeal, almost like RF interference or something. It is apparent at all gain stages and output volumes (at various amplitudes). At first I thought it was noisy electronics in the instruments, but the issue is not happening in my copper. Engaging the pad helps the matter slightly but doesn't really resolve the issue.
2) when in DI and Mic mode, With the Grayhill fully clockwise, and the pad engaged, the last 1/8th turn "clicks" and then it makes a equaling noise. But this only happens with the grayhill fully counter clockwise…not that I would ever probably need to max this thing out like that, it would seem to be an indication of something not being quite right.
3) With a mic connected, the final position of the Grayhill decreases gain, with slight distortion. normal?
The bronze seems to have more "noise" than the copper, perhaps this is normal.
Most these observations where made without a mic/guitar/etc being plugged in, just the sound of the module itself. My primary issue is with the DI ringing/squeal. I plan on reflowing some of the gray hill points to see if that fixes the final stepped gain issue. Any thoughts would be appreciated. I would rather try to trouble shoot this thing so I can learn something in the process.