SD9 Problem (no Dist, oscillating)

[tungngruv]

I built the SD9 from GGG. For some reason, I'm not getting any effect signal although I can hear changes in the hiss when I mess with the controls. There is also a high pitch squeeling going on that raises and lowers pitch as I adjust the gain and tone knob (kind of cool but not the effect I was after   :lol: )
Here are the pin and transistor voltages;

4558

1 - 7.59
2 - 7.59
3 - 0.0
4 - 0.0
5 - 1.86
6 - 1.94
7 - 4.40
8 - 8.77

2N3904

E - 2.39
B - no reading
C - 8.7

Readings were the same when I switched the pedal off, although I couldn't get a reading from pin 5 again for some reason. BTW, I did search the archives and found some people had the squeeling problem but didn't really see a solution. I'm done with it for the day. I'll recheck the wiring tomorrow after I've rested and eaten something. Thanks in advance for any help, I'm sure I've got a wire shorting or not connected somewhere.

[MartyMart]

Hi, its early in the UK ( noisy neighbour ! ) so i'm up !
looks like your readings are off a bit, here's mine from a working version, hope this helps you out:
op-amp: Ti 4559
Battery - 9.31v
1 - 8.55v
2 - 8.55v
3 - 0.00v
4 - 0.00v
5 - 4.16v
6 - 4.6v
7 - 4.6v
8 - 9.2v

2N3904
C - 3.13v
B - 2.76v
E - 9.2v

There must be a miss-wire or bridge somewhere ? check your resistor values, i've installed some that were way off recently !!
you know what to do. . . . . "debugging"    YUK !!!
Good luck,
Marty.
EDIT:
If your readings are the same with no power connected, then you have a power short somewhere?  should be 0v everywhere, are you using the old "stereo jack" for power ?  check that wiring man!  M.

[tungngruv]

Thanks Marty, I'm sure I missed something stupid. You know, the boards together, the pots are mounted, I can almost hear it then............Oh well, like I said, I'm going to go lay down now (and stare at the ceiling in the dark) and try to get some sleep. Also, I DID happen to use an old plastic TRS jack that I used in desperation. HMMMMM, I wonder. Thanks again.

[tungngruv]

OK, I just printed off the SD9 layout from GGG, and marked a line from each part, all the way through the circuit. Every part is connected the right way but pedal still is not working. I'm going to the debugging page now and I'm going to double check every resistor and cap. I really thought this would be a short somewhere but all the connections look clean??? Anyone else have this type of thing happen? I wonder if the DPDT switch is bad? I get bypass sound OK, although some of the squeeling comes through even when bypassed. When the effect  is "on" , I'm only getting a hiss and pooping kind of noise. This is weird.

[tungngruv]

Huh, I guess it does matter if the input and output wires go to the right poles of the switch :oops:  Pedal sounds great although the gain recovery is a must for this one.

[aron]

Is the output low on yours?

[tungngruv]

Yeah, everything works now, pedals nice and quiet but I have to have the volume on about 2:00 just to keep unity gain. I read this is common as I was  looking through the posts trying to fix it (although it wasn't broken, I was)  :lol:

[aron]

I was trying to remember if mine was like that. Hmmm.

Well it's a great pedal!

[tungngruv]

RDV put a lot of good info out on it, and the volume recovery he designed.