Mark Hammer Woody with ICL 7660 - DEBUG HELP!

[Carlos Best]

Guys!
I'm struggling to fix the errors in yet another version of this pedal.

I made a PCB with jacks and 3pdt included. In my layout I used a ICL7660 for the voltage doubling, and I think that I messed up something in the power area cause
altough everything seems fine even the first opamp woun't amplify anything

Here is the eagle schematic. Please help me checking if earth and "virtual" earth connections are ok
http://img194.imageshack.us/img194/7215/jv69.png

There is one spot of the top/bottom pots where I can hear some sound coming trough,
I think that the pots are sorta biasing the opamps into amplification
Here are the voltages without ICS (only the ICL7660) left column, voltages with the ICS right column (in that particular spot where I can hear sound)

tl072

1 0         15
2 0         10,9
3 7.3       10,9   
4 gnd       gnd   
5 7.3       10,9     
6 7,3       10,9   
7 7,3       10,9 
8 16,8      16     


tl074

1 7,3     14,9
2 7,3     14,9
3 0        14,9
4 16,3    16
5 7,3     10,9
6 7,3     10,9
7 7,3     10,9
8 7,3     15,1
9 7,3     10,9
10 7,3    15,1
11 gnd    gnd
12 7,3    14,9
13 7,3    10,9
14 7,3    15,1

Tested with a regulated 9v power supply

Thanks in advance.

Regards

[Mark Hammer]

There are +9v layouts.  Send me a pm

[Carlos Best]

PM Sent

You mean that there are single supply layouts with voltage doubler?

[Mark Hammer]

Personally, I would be skittish about using a charge pump with this sort of circuit.  Keep in mind that charge pumps use high-frequency clocks to produce the outputs they do, and analog acoustic emulators provide lots of boost to high frequencies.  From a noise perspective, this is a dangerous combination, and a layout challenge.

Better to either use a pair of batteries, or a circuit adapted to a single-ended supply.  A forum member was kind enough to send me a board they had made, adapted to a single-ended supply and I can confirm it sounds just fine.