This may not be a troubleshooting thread at all, but its more more of a gap in my understanding. Bear with me. I hooked this up to an Auditorium and after the pedal failed to work in effects mode I put an audio probe to it and got signal pretty much from the volume pot all the way to C1. I was satisfied that the signal path could work, but it was choosing not to do so. Voltages looked very weird.
NE5532 (9.37v)
1. 7.48
2. 7.42
3. 7.48
4. 7.99 (!!!)
5. 7.28
6. 7.67
7. 8.49
8. 9.13
TL072 (9.37v)
1. 7.27
2. 7.30
3. 7.27
4. 0.00
5. 7.27
6. 7.28
7. 7.08
8. 9.13
None of that made any sense at all, and I wasn't totally trusting the Auditorium board so I switched over to the breadboard to test the power rail. (voltages are just different there, different supply). With 8.6v in I was getting 8.35v at VCC and 6.68v at VRef (!!). I duplicated the circuit on the breadboard itself real quick and it behaved normally, with Vref being half of VCC.
Eventually I noticed that the ground wire was stranded (and kinda floppy) while the +9v wire was solid core. I swapped out the ground wire for a solid core wire and all my voltages settled into where they are supposed to be. I took a quick reading of the TL072 before going to bed (it was past midnight, too late to try to get sound) and it was a very different story.
TL072 (8.11v)
1. 3.82
2. 3.82
3. 3.82
4. 0.0
5. 3.82
6. 3.82
7. 4.08
8. 7.84
Like I said, I haven't had a chance to wire this into the Auditorium and see if I get a signal yet so I may not have a problem at all. But I don't understand this behavior. I get that a bad ground is going to make things off, but it seems like the power rail is just math. Voltage dividers will divide the voltage no matter what. And I was getting ground before swapping the stranded wire out, there was continuity and the readings were consistent at various points. Can anyone explain this?
NE5532 (9.37v)
1. 7.48
2. 7.42
3. 7.48
4. 7.99 (!!!)
5. 7.28
6. 7.67
7. 8.49
8. 9.13
TL072 (9.37v)
1. 7.27
2. 7.30
3. 7.27
4. 0.00
5. 7.27
6. 7.28
7. 7.08
8. 9.13
None of that made any sense at all, and I wasn't totally trusting the Auditorium board so I switched over to the breadboard to test the power rail. (voltages are just different there, different supply). With 8.6v in I was getting 8.35v at VCC and 6.68v at VRef (!!). I duplicated the circuit on the breadboard itself real quick and it behaved normally, with Vref being half of VCC.
Eventually I noticed that the ground wire was stranded (and kinda floppy) while the +9v wire was solid core. I swapped out the ground wire for a solid core wire and all my voltages settled into where they are supposed to be. I took a quick reading of the TL072 before going to bed (it was past midnight, too late to try to get sound) and it was a very different story.
TL072 (8.11v)
1. 3.82
2. 3.82
3. 3.82
4. 0.0
5. 3.82
6. 3.82
7. 4.08
8. 7.84
Like I said, I haven't had a chance to wire this into the Auditorium and see if I get a signal yet so I may not have a problem at all. But I don't understand this behavior. I get that a bad ground is going to make things off, but it seems like the power rail is just math. Voltage dividers will divide the voltage no matter what. And I was getting ground before swapping the stranded wire out, there was continuity and the readings were consistent at various points. Can anyone explain this?