Dirtbag Troubles

[LaceSensor]

touch where exactly 

[tenwatt]

touch where exactly  

If I touch the bare "Level" pot shaft (no knob) with my bare finger (or bare toe so that I can test it with out whine) it stops the whining that occurs when I turn the "Delay" pot up.

[LaceSensor]

nope still there either way on mine

[tenwatt]

Signal seems a bit hot coming off pins 3&4 of each BBD. I'll need to get some voltages from mine for comparison.

One possible solution to reduce distortion is to reduce the signal input to the BBD's even further. This is untested but here are a couple of ideas:

Temporarily disconnect R18 to see if the overload LED is having an influence on noise.
Increase R21 to 100k and reduce C14 to 3n3.
Lower R11 and R12 down to 33k.

Also, do you have the two GAIN trimmers turned all the way down?

Hey Brian,

Have you read our recent problems?  Do these ideas still apply?  I just don't want to have to do anymore desoldering than I have to. 

[Scruffie]

Signal seems a bit hot coming off pins 3&4 of each BBD. I'll need to get some voltages from mine for comparison.

One possible solution to reduce distortion is to reduce the signal input to the BBD's even further. This is untested but here are a couple of ideas:

Temporarily disconnect R18 to see if the overload LED is having an influence on noise.
Increase R21 to 100k and reduce C14 to 3n3.
Lower R11 and R12 down to 33k.

Also, do you have the two GAIN trimmers turned all the way down?

Hey Brian,

Have you read our recent problems?  Do these ideas still apply?  I just don't want to have to do anymore desoldering than I have to. 

Yes they would still apply.

I can't find my copy of the Compander cookbook to get the correct equation to know where best to set R11 & 12 but somewhere between 33 & 47k may be a good choice.

But both methods just decrease how hard the BBDs are smacked in the first place so give them a whirl, you can make up gain later.

[LaceSensor]

IF I were to do one thing at a time whats likely most beneficial ? the resistor pair on the compander?

Cheers

[tenwatt]

Let me get this straight, though.  If I disconect R18 and the problem goes away are the other mods neccesary?

*EDIT* Sorry, Lace.  I was typing as you posted.

[LaceSensor]

I was just about to d/c R18 if you wanna wait for me to try it?

[LaceSensor]

R18 doesnt make a difference on my build

[Scruffie]

Let me get this straight, though.  If I disconect R18 and the problem goes away are the other mods neccesary?

*EDIT* Sorry, Lace.  I was typing as you posted.

If it goes away it goes away, but I don't think it'll help, could be wrong there though.

The other methods make more sense as they're reducing the gain that smacks the BBDs.

Sockets would be my suggestion for R11,12,21 & C14 untill a good balance is found.

I'd breadboard the circuit but I don't have all the parts yet.

[LaceSensor]

socketed R11 and R12 with 33k in there its not really any better

[LaceSensor]

100k in r21 makes things more extremely muffled and severely limits repeats but i can still hear distortion on the repeat
struggling to get c14 out already screwed one pad on r21 luckily it was salvagable

[LaceSensor]

gotta go out.

If tenwatt tries c14 that'd be cool. if I ruined the pads, how easy would it be to jumper?

[tenwatt]

gotta go out.

If tenwatt tries c14 that'd be cool. if I ruined the pads, how easy would it be to jumper?

Since you've already done the others I'll start with C14 tonight.  It will be another four hours or so before I get to mess with it but if you haven't done it before then I'll be all over it.  That is IF I have a 3n3.

[Scruffie]

gotta go out.

If tenwatt tries c14 that'd be cool. if I ruined the pads, how easy would it be to jumper?

Since you've already done the others I'll start with C14 tonight.  It will be another four hours or so before I get to mess with it but if you haven't done it before then I'll be all over it.  That is IF I have a 3n3.

Doing Just C14 wont do anything, you have to do it in conjunction with R21 because together they form a... (this is the bit where you're meant to learn).

*Hint* Big Muff Tone Control Blends between them.

This is why your repeats became muffled when increasing R21 but not changing C14.