Blender woes

[Widows]

Hi everyone,

Im building a Rat with a clean blend, and having checked the invidivual boards separately and in tandem, I've installed em in the enclosure and low n behold, no sound when engaged. Tested with my audio probe from the output back, and the signal stops at lug 2 of the blend knob. The Rat board is working fine.

Schem and board are here:
http://pedalparts.co.uk/docs/Blender.pdf

I've tried swapping the pot out like for like but the problem still prevails. Can anyone suggest anything else to check? As you can see on the schem, the only thing connected to lug 2 is the output wire to the jack so if it's not the pot, I'm a little stuck....

Edit: I've tried jumpering the output pad of the blender to lug 2 to see if it eliminates a broken track being the issue but still nothing


tia

[antonis]

Have you wire it as a blender or as a looper..??

[thermionix]

So you have sound at lugs 1 and 3?  If so, bad pot.

[Widows]

Antonis: as a blender, as far as I can tell. Jacks go to in and out, Rat board goes to send and return

Thermionix: That's what I thought, I changed the pot but the problem is still the same

[blackieNYC]

Does your rat invert phase perhaps? I would expect that to give you a very weak and thin signal at pin 2, but signal, regardless. 

[R.G.]

Im building a Rat with a clean blend, and having checked the invidivual boards separately and in tandem, I've installed em in the enclosure and low n behold, no sound when engaged. Tested with my audio probe from the output back, and the signal stops at lug 2 of the blend knob. The Rat board is working fine.

What I think you said is that
- you have checked both the blender board and the Rat board, and they both work by themselves
- you have tested the two boards "in tandem", which I think means that you tested them for working as a blend outside the enclosure.
- the "in tandem" setup then does not work when put inside the box
If I got that right, you ought to be looking for how the box installation is shorting something out or opening something.

If I missed your meaning, tell me, or better yet show me the wiring diagram of how you actually have this wired up, in a picture.

You mention testing with your audio probe from the output backwards. Have you tested from the two inputs forward to be sure that your signal gets from the input to the send jack and pot, and from the receive jack to the other end of the pot?

[thermionix]

Output jack is wired backwards.  Lug 2 signal going straight to ground.