8-ball just buzzes

[Jay.lingelbach]

Hello all. My second project is an 8-ball. Having some issues. Rocking before boxing has been followed. The pedal won't pass a bypass signal. When turned on passes a nasty hum and some audio signal from the guitar. Being new. I'm sort of stuck.
Things that I have verified and checked:

Both guitar cables work when plugged directly into the amp.

I did find I had the one IC in backwards. No progress.

Values at the pins are added as an image below.  Along with the voltage coming in at the board from the power supply.

Note: these are definitely off from the build guide values listed. Also included as an image for reference so you don't have to go searching for those values.

Also I am having the exact same problem with another build. (Swedish chainsaw) so maybe it's my test rig?







Test rig (led not hooked up)




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[Jay.lingelbach]

More pics.



Under volume pot


Under gain


Under tone



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[gordo]

Check your bypass switch wiring. Yours looks like 2nd and 3rd row of pins are swapped.

[zgrav]

If your bypass signal is not working there is no real reason to check things on your pcb since a bypassed signal should never leave the footswitch.

[alanp]

Hate to tell you this, but it looks like your DPDT switch is lopsided.

It's going to be a pig of a job to straighten it up without ruining either the switch, the board, or both.

[Jay.lingelbach]

Hate to tell you this, but it looks like your DPDT switch is lopsided.

It's going to be a pig of a job to straighten it up without ruining either the switch, the board, or both.

I had noticed that! The silly thing has a ridge running down the center of it. Couldn't get it to sit flush.  If I can't get it to work in an enclosure I might just scrap it and do it all over. Any recommendations on dpdt that don't have a ridge down the center?


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[Jay.lingelbach]

Hate to tell you this, but it looks like your DPDT switch is lopsided.

It's going to be a pig of a job to straighten it up without ruining either the switch, the board, or both.

I had noticed that! The silly thing has a ridge running down the center of it. Couldn't get it to sit flush.  If I can't get it to work in an enclosure I might just scrap it and do it all over. Any recommendations on dpdt that don't have a ridge down the center?


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[Jay.lingelbach]

Hate to tell you this, but it looks like your DPDT switch is lopsided.

It's going to be a pig of a job to straighten it up without ruining either the switch, the board, or both.

I had noticed that! The silly thing has a ridge running down the center of it. Couldn't get it to sit flush.  If I can't get it to work in an enclosure I might just scrap it and do it all over. Any recommendations on dpdt that don't have a ridge down the center?


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[Jay.lingelbach]

Hate to tell you this, but it looks like your DPDT switch is lopsided.

It's going to be a pig of a job to straighten it up without ruining either the switch, the board, or both.

I had noticed that! The silly thing has a ridge running down the center of it. Couldn't get it to sit flush.  If I can't get it to work in an enclosure I might just scrap it and do it all over. Any recommendations on dpdt that don't have a ridge down the center?


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[Jay.lingelbach]

Sorry for the multiple post. Tapatalk went crazy


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[Jay.lingelbach]

Sorry for the multiple post. Tapatalk went crazy


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[somnif]

The way I do it, to make sure things fit, is drill the enclosure, insert the pots and switches, then set the board down onto the pins and solder once in place.

Helps make sure that any alignment issues I have are (mostly) taken care of before I have solder joints to worry about.

[zgrav]

I agree with somnif.  Putting the switches and pots on the pcb and into the enclosure before soldering the pins solves a whole lot of alignment issues and eliminates stress at the contact points on the pcb.

[Jay.lingelbach]

Ok. Got the switch wired up so it sends a bypass signal through. No sound when I hit the switch and turn the effect on though.


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[zgrav]

basically you check three things for troubleshooting.  voltages at the ICs and transistors, Ground continuity at points that are supposed to be grounded, and following the audio signal through the effect.  I would do those in that order, just because it is easier to use your DMM to check volts and ground.  for the audio, the easiest thing to do would be to put together a simple audio probe so you can confirm where the audio is going.  Pretty sure you can find a simple guide on this site to make one, since it is just a cable with a phone jack on one end, a ground clip you attach to the circuit ground, and an electrolytic capacitor connected to the audio cable wire (the capacitor blocks any dc voltage from going to whatever speaker you  have plugged the phone jack into).  it helps if you have something that can play a sound into your pedal while you are testing it.  I use my ditto pedal to do that, but some folks will plug in their guitar and tap some strings while using the probe.