Procastinator / Dr Q / Orange Squeezer No Sound

noahjbauch

noahjbauch

New member
I've been trying to build a 3-in-1 pedal that has a PedalPCB Procrastinator going into a Tayda Dr Q autowah and then into a Tayda Orange Squeezer compressor. I currently have two problems.

There is no sound when the pedal is on, no matter where the knobs or trimmer pots are set.

I also can't seem to set the trimmers correctly because I don't get readings anywhere near 4.5 on the transistors.

Procastinator is on the left, Autowah is on the right, and comp is the little guy at the bottom.

Let me know what questions you have so that I can help you help me!
 

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That means you are shorting your input signal to ground from the get go, so not a surprise you don’t have sound. I can’t say I have ever heard of that step in biasing a pedal and have never done that when biasing things like fuzz or BBD circuits. I would remove that and give it another try. Out of curiosity, why compression after? Usually a compressor before the procrastinator makes it behave a little better.
 
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Right, I added that after I had tried a bunch of stuff and was thinking that the biasing might've been the problem. But I definitely tested it a bunch beforehand without that wire there.

So for biasing, I need to get 4.5 V coming off the collect lead, right? And if the flat side of the transistor is facing you, the collect is the one on the right? Does it matter where all the other pots are set?

I also think part of my trouble biasing could be my multimeter. It's pretty old and has been acting up lately. Is there a multimeter you would recommend that's pretty high quality but also just the features I need for basic pedal work?
 
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Well all of them! They each have a trimmer pot, but I'm having a hard time figuring out which transistors and which leads I should be measuring.

Thanks for the recommendation!! I'm gonna order it now so maybe in a couple days I'll be able to get some more accurate readings.
 
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So none (or at least 2/3 and anyone is welcome to correct me) of those trimmers are actually for biasing the transistors. Tayda didn’t have a build doc for the squeezer, but looking at the project on general guitar gadgets, that’s just an output volume control. For the Dr Q, the range sets the, well, range of the sweep meaning how much low and high end you hear when the envelope opens. For the procrastinator, the trimmer MAY have something to do with biasing, but I never adjusted it as such, it’s more of a “play into the pedal and adjust to desired responsiveness”.
 
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Gotcha! So I should get some sort of manageable audio signal no matter where they're set? If that's the case, then I guess I need to just use a probe to trace the signal? I've only done that once or twice, so I'll take any tips I can get. Like which transistor leads should give me audio? And which pins on ICs?
 
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if you aren’t getting audio signal and you have done a full visual inspection of component values, wiring, and soldering then audio probe is the next step. I would start by setting all trimmers to 12:00 and then test just the in and out of each circuit to narrow down which circuit to start deep diving on. One thought though, considering the procrastinator and Dr Q are both envelope filters I am wondering if the output of the procrastinator is strong enough to open the filter on the Dr Q. I would set the sensitivity knob on the Dr Q really low and maybe put a boost in front of the procrastinator. Really and truly I personally would disconnect all the circuits and test them individually so one isn’t influenced by the circuit before it.
 
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Diynot said:
So none (or at least 2/3 and anyone is welcome to correct me) of those trimmers are actually for biasing the transistors. Tayda didn’t have a build doc for the squeezer, but looking at the project on general guitar gadgets, that’s just an output volume control. For the Dr Q, the range sets the, well, range of the sweep meaning how much low and high end you hear when the envelope opens. For the procrastinator, the trimmer MAY have something to do with biasing, but I never adjusted it as such, it’s more of a “play into the pedal and adjust to desired responsiveness”.
Click to expand...
1681692793042.png
 
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that’s the tayda schematic for the orange squeezer. Looks like the trimmer is biasing the jfets. @noahjbauch jfets use different terminology but for our purposes pretty similar idea as bjts. Emitter - base - collector is source- gate- drain. Where did you get your 2n5457s?
 
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