Pork Barrel: No Sound when engaged

[keysandguitars]

I have had a few issues with wiring the power and jacks on this build. My guitar signal now passes through in bypass mode and I get no sound when the effect is engaged.

I have taken a razor to the pcb to make sure I don't have solder bridges, I've reflowed joints, etc. The board looks good. I am wonder if I have screwed up wiring the pots?

I am a bit confused by the note at the bottom of the pdf wiring diagram that states:
"You can use this as a guide for the double sided version. Note that the single
sided version has the pots wired 1-2-3, and the DS version has them as 3-2-1"

I purchased the pcb from Brian so I have the double sided version. Could someone please clarify the statement above? I wired the pots with the lugs toward the pcb with the back of the pot facing up. The pcb is component side up. I hope that is clear enough. If not, I can try and upload a photo later tonight.

TIA, Brandon

[k.rock!]

Hey Brandon!

If you look at the back of the pot, the lugs are labeled like this

(back)
3-2-1

So basically, your pedal should look like this

(back)    (back)
3  2  1    3  2  1
_____________
|      PCB       |
|  component  |
|       up        |
---------------

instead of this (like the single sided version diagram shows):

3  2  1    3  2  1
(back)    (back)
_____________
|      PCB       |
|  component  |
|       up        |
---------------

Sounds like you have them correctly mounted, so I would look somewhere else in your PCB. Could you post some pictures?

There is a handful of things that could be going on so we would need to have a look before shooting in the dark


-Kaleb

[gtr2]

Just a shot in the dark...  If your looking at the box from upside down make sure you have your input plug in the input jack and output plug in the output jack.  This may not be your problem but sometimes the most obvious solution is the one overlooked.

Josh

[keysandguitars]

Thanks guys, I will double check these things first and try and take some good close-ups when I get home from work. I appreciate your responses and time.

[irmcdermott]

The first things that I always do/check when I get signal when bypassed but nothing when the effect is on is to check with my DMM to make sure I'm getting the correct voltage to the PCB, and always double check your switch wiring.

[mgwhit]

Reverse-wired pots rarely result in absolutely no sound.  I'd concentrate on the jacks and the footswitch for the time being.

Josh's suggestion is a classic for the "bypass works, but no sound when engaged" issue (I was going to recommend it myself), but there can be other problems that result in the same behavior.  Definitely check the jacks and the footswitch to make sure that all lugs that should have continuity to ground have it.  The one place that I've been bitten by a bad solder joint is on a 3PDT switch.

[bigmufffuzzwizz]

The first things that I always do/check when I get signal when bypassed but nothing when the effect is on is to check with my DMM to make sure I'm getting the correct voltage to the PCB, and always double check your switch wiring.

I always try this too and 3 out of 5 times this is the problem.

[keysandguitars]

It very well could be the 3PDT. I purchased some from Mammoth which I really don't like:
http://www.mammothelectronics.com/4SFS3PDT-LS-I-p/800-1006.htm I prefer the switches sold by PPP http://www.pedalpartsplus.com/mm5/merchant.mvc?Screen=PROD&Store_Code=PPP&Product_Code=9000&Category_Code=SWI

The lugs are a lot bigger and easier to solder cleanly too. No excuses for cold solder joints, but for a noob, I'd get the CliFF3PDT's.

I'll give the suggests a rip asap, can't wait to get home. Thanks to all!

[keysandguitars]

Ok, so I rewired the switches and jacks. It looks like I had it correct, I must have had a bad joint. So now I have signal and am trying to calibrate the trim pot and the chorus is there but it kind of has an abrupt rise and fall, kinda like a ping pong or panning effect. I'm checking cap values now and will check the voltages. I have no clue what it is that would cause this so I'm just checking everything for good measure.

Thanks again for the earlier input, I'm one step closer.

[keysandguitars]

I'm stumped. I've checked cap values, wiring, etc and the chorus isn't happening. When engaged, the effect is an abrupt rise and fall instead of a nice smooth modulation. I'll record a sound clip tonight. Could this be an issues with an IC? I bought them from Smallbear.

[keysandguitars]

Ok, so it sounds like the vibe mod is on...even though i've removed all the mod switches. Could that be possible, that something is shorted or bridged and it's activated the vibe mod? Sorry for the lack of tech speak. It's modulating, but very sharply, just warbling up and down abruptly. Any thoughts?

Also, when I turn the mix knob all the way down, I lose almost all volume. I read in another post that this is true of the vibe mod as the dry signal isn't present. The wet signal with the mix all the way up is fairly softer than the dry bypassed signal.

[keysandguitars]

I recorded a little bit last night, sorry for the grounding hum here and there. I'm adjusting the trim pot back and forth with the knobs set as recommended and then just turning the rate knob.

Does this sound like the vibe mod is engaged? I completely removed the wiring and switches for all mods last night prior to recording.
Memo.mp3

[jkokura]

It sounds to me like your dry signal is not getting through, so that is just the 'chorused' signal, which is what happens when you throw the Vibe switch. Also, it doesn't quite sound as musical as I remember the Pork Barrel being, but...

Really, you should get out an Audio Probe and begin to sort through the circuit and find where the problem is. Have you seen the "How to get Tech Help" thread?

Jacob

[keysandguitars]

Thanks Jacob. It doesn't sound musical at all to my ears, but I'm hoping that'll change as I debug the circuit. Chromesphere (I think that's his forum name) suggested that it sounded like the vibe mod was "stuck on". I was trying to figure out how to check that out last night, but didn't really know where to begin other than looking for bad solder joints or shorts.

I did read the how to get help, I hope I haven't violated procedure. I've checked all my values, connections (several times) and am as far as I can get there.

I am going to build an audio probe tomorrow and figure out how to use it maybe using this link as a guide to learn how to properly go through the circuit (unless anyone knows of a better tutorial.) http://www.geofex.com/fxdebug/newfx.htm