Pork Barrel Popping when switched on and off

[Ric046]

Hi

I seem to be having a problem with my newly built Pork Barrel chorus pedal. Every time I click the foot switch on or off I get a big loud pop through my speaker.

I've read the forums on this problem and attempted most of the possible solutions, but without success.

I've checked everything is grounded properly, I've changed the 3PDT switch, I've disconected the LED, I've tried the pedal in a different speaker, plugged the power supply into a different wall socket, I've even add a 100k res. between the tip and the ground of the out jack socket as recommended by a forum user.

Please help. This is my first ever build and as it stands the pedal is unusable to me coz the popping will rip my speaker if I cranck the amp. It's that loud! Other than this the pedal is in complete working order and sounds great.

Cheers
Ric

[jkokura]

If you've tried the usual solutions, one last thing you may not have tried is replacing the switch. Sometimes, it's the switch itself which is faulty.

Jacob

[Ric046]

Hi jacob, I have tried changing the switch and unfortunatley the problem remained.

So if the switch is fine, the pedal is properly grounded could this only mean there's a problem somewhere on the board?

[madbean]

You definitely do not want to have that 100k from tip to ground on your output jack. That resistance will be there even in bypass, and could cause some tone suck.

How did you wire your 3PDT switch? Have you tried a larger R1 resistor...says 2M2? Or, perhaps try increasing R13 to 1M.

[Ric046]

Hi Madbean. 100k was removed as soon as it didn't solve my issue.

I wired up the 3PDT from the 'Standard Wiring Diagram For Madbean Pedals' via the link on the Pork Barrel instructions. I used the second diagram, (the one with 'Pepper Spray' PCB illustration) as this more ressembled the Pork Barrel PCBs in/g/out. I left out the batt snap as I have no room for a battery in my enclosure.

I will try adding those resistors to R1 & R13 one at a time and see if they get rid of the problem.

Cheers
Ric

[Ric046]

Hi, no luck when changing the resistors. I changed both R1 and R13 to 2M2 and 1M respectively, popping still there as loud as ever.

I built a test box to help me change and test the new resistors more efficiently. The test box has a three postion throw switch - on/off/bypass - and between on/off off/on I get the popping. Between off/bypass bypass/off I get no popping like I'd expect.

The only constant throughout has been the circuit board, as the test box has a whole new 3pdt switch, jack sockets, DC socket etc.

Can I ask a quick question about the test box? I have 4 leads coming out for audio in and out, +9V and G. I'm not connecting the lead that comes from directly next to the +9V on the Prok Barrel PCB. Is this a problem?

Cheers
Ric

[madbean]

You do not have to use the extra ground next to the 9v pad.

Only other thing I can think of it to replace C1 and maybe even C7. If the caps are faulty or very leaky then they could cause the pop. The pulldowns should take care of that, in theory, but it is worth a shot.

Also, are you only using a regular indicator LED, or are you also using the LFO LED indicator as described in the doc?

[Ric046]

HI, changed both the caps and no change, the same loud popping remains.

I used a regular LED in both the pedal when I boxed it and the test box I'm now using.

Could I send you a photo of my board to see if you can see any irregularities.

Cheers
Ric

[Ric046]

...Also I have tried the pedal without any LED just to see if that was creating the problem. But the problem remained.