Hi everyone, I built a new fc526 xfmr, just got the test jig built, powered up, checked opamp connectors and tp9, all good, loaded red dot opamp and began calibration process. In CAPI 511vpr rack with extension jig, test signal from DAW and monitoring signal with Southwire 10040N DMM I ran 200hz sine wave out at 24.5 mV, reading the same in bypass but significantly higher than expected in active with both gain pots all the way up. It was :
output= 2.349 V AC.
Reading the first three test points gave:
TP1= 12.1 mv, TP2= 199.2 mV, TP3= 1.587 V.
I looked through the support thread and did the first step of checking solder points, retouching anything that might be bad but no change. It seemed other people had a similar issue and it seemed possible that resistors near the input could be misplaced but I'm not sure how to test them on the board other than by colored bands. Comparing my board to pictures online of working units I can't see any differences. I'm still a beginner as far as electronics but I have also built 4 vp28s and a bt50 and they all came out well so I'd love to figure out what's wrong. I wondered if the user Jeremiah Blair had any luck tracking down his issue since it seemed similar although with different specific values. Also of course I am limited by my equipment, it is possible that the build is fine and my DMM is not accurately reading the voltage or some other outside issue I'm not thinking of. Any ideas anyone here could give me would be very appreciated, thank you!