Bi Polar Power supply (positive ground fuzz)

[fuzzfreak]

I am attempting to wire up a ge poz ground fuzz face with a tc1044 chip using this layout. very similar to the road rage.

I keep frying the chip though.  I am using a power supply, connecting the out-9v to the -9v on the board and out 0v to the (positive) ground on the board.  I have the polarity of the caps correct to the road rage schematic.  Has anyone here done this?

[jimmybjj]

hi while I don't know enough to comment on your problem, I thought I would share the link I found http://www.geofex.com/circuits/+9_to_-9.htm
looks to be similar to your idea with some variations that might help your situation. Sorry, if you have already seen this link.

[madbean]

This looks correct. What voltages are you reading off the pins of the charge pump?

[fuzzfreak]

I am using a DMM and grounding to the PS while taking each of these measurements.
1:+9.64v
2:+9v
3:0v
4:1.6mvv
5:+9v
6:+8v
7:+8.7v
8: +.5v

I would like to be able to use this fuzz with a one spot that is powering the rest of my effects and this seems to be the only solution i could find that will work.  so has anyone else experienced this?

[jimmybjj]

I don't think this is verified. But they are talking about what your after.

http://circuitworkshop.com/forum/index.php?topic=682.0

if linking to another forum is prohibited or uncouth, I apologize. Let me know and I will edit the link.

[dwstanford]

I've built a few pos ground fuzzes with pretty much identical layouts before with no problems.  Make sure you have the chip orientation correct.  You can definitely cook it if you have it in backwards. 

[madbean]

Unless you have a really bad chip, you have not listed the pins in the correct order. It should be

1--u--8
2|||||7
3|||||6
4|||||5

[fuzzfreak]

Sorry I listed them like this.

1--u--5
2|||||6
3|||||7
4|||||8

any thoughts?

[fuzzfreak]

no one?

[madbean]

What you listed as pin8 (pin 5 actual) should read -9v. IIRC, the two pins directly above it should read about 4.5v.

Were those voltages taken with the charge pump connected to the fuzz, or on its own?

[ibodog]

I had the exact same thing happen on a similar circuit last week.  Turned out I was tired and had the wires switched going to the fuzz pcb.  Double check your schematic and layout and make sure you haven't switched them.  That charge pump can get really hot if you do.

[gtr2]

Some pics could possibly help.  Extra eyes are always good!