Build Your Own Clone Message Board

Hello, I’m new to building effects. Made the confidence boost without issue, and completed the classic distortion, but it’s not working for me. Here is the situation:

Bypass working fine and is clear
When switched LED lights up, but absolutely no signal going to the amp

I’ve tried both wall power and new battery, double checked my resistor codes and placement of components, resoldered all the wires (which is why they are all on the same side now), and some possible suspect components. Still no luck. What did I miss or what should my next step be?

Thank you ahead of time for your help!

-Phillip

Just checking - is there good clearance between the middle pot and the circuit board when you put it in the case? Since my Silver Pony build, I’ve always put a strip of electrical tape on the bottom of the pot to prevent shorts, just in case.

I don’t know this circuit well enough to check components - it does seem like you’re soldering is OK, I didn’t spot any obviously dry/cold joints.


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Component placement looks good. Your soldering looks good, but it couldn't hurt to reflow all your PCB joints again. Your op amp likes like it might not be in the socket all the way. Make sure that is firmly seated.

If that doesn't fix it, please take voltage readings of the op amp and the transistors.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

The insulation on the bottom of the tone pot is a good tip. You might also want to pull the IC and re-seat it, since it looks a bit crooked to me and might not be all the way down in the socket. Also, if you happen to have another 4558 or compatible general purpose dual op amp (TL072, NE5532, OPA2134, etc.) that you know works (e.g from a functioning pedal), try popping that in there and see if the pedal springs to life.

In case none of that bears fruit, do you have access to a multimeter and know how to use one?

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Thanks guys! I will look at insulating the tone pot and reflow the joints on the pcb when I get home. Will update you after that.

As for the op amp, I've already tried re-seating it. I don't have access to another comparable op amp right now (but can probably track one down over the next few days). I do have a multimeter, but I'm not entirely sure what to look for while testing the op amp or the transistors.

With power supplied to the pedal and a cable in the input jack, set the multimeter to read DC voltage. If it's not an auto-ranging meter, set the voltage range to 20 VDC. Contact ground with the black probe (I recommend just placing the probe in one of the four corner screw bosses of the enclosure for this purpose) and then touch the red probe to whatever point of the circuit you wish to test.

Measure all 8 pins on the op amp; pin #1 is the one with the square solder pad on the PCB, and the rest are numbered in a "U" shape around the IC. Assuming a power source voltage of 9.0 VDC, pin 8 (directly across from pin 1) should be at that source voltage, pin 4 should be at ground potential (0 VDC), and the other six should all be right around 4.5 VDC. Post your results here. We'll see how that looks and can then move on to the two transistors based upon your results.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Okay, here are the results of the test:

Pin 1: 4.46v
Pin 2: 4.11v
Pin 3: 4.46v
Pin 4: 0v
Pin 5: 4.46
Pin 6: 4.37
Pin 7: 4.37
Pin 8: 9.11

I insulated the back of the tone pot with some electrical tape as well. Still nothing when the switch is enabled. There is a slight hum when I turn the amp volume up a bit.

Those voltages look fine. Next, use the same method to take voltage readings on the three legs of each of the two transistors. They are designated Q1 and Q2 per the PCB map below:

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Q1
E: 3.06v
B: 2.63v
C:9.11

Q2
E: 3.03v
B: 2.62
C:9.11

Those voltages look good, too.

Three ideas at this point:

1. It would be worth the effort to test the function of your footswitch and make sure that isn't the problem. When in the engaged mode, the internal footswitch connections between lugs 4 & 5 and between lugs 7 & 8 are necessary for the audio signal to flow into and back out of the effect circuit. Use your multimeter to check for continuity (i.e. ~zero resistance) between those two pairs of lugs when the switch is engaged.
2. If the footswitch checks out OK, I think it would be useful to work through the process described HERE, just in case there's a solder problem somewhere in the pedal. Your soldering looks quite good, but such problems aren't always visually evident.
3. If that approach bears no fruit, I'd replace the IC. They're the most delicate & failure-prone component in the circuit and they're cheap, so that's definitely worth a shot if nothing else is helping. Worst case you end up with a spare dual op amp on hand.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Thank you for all of the very responsive support!

Switch checked out and I reflowed all of the components. I'll order another IC and hope that works things out. I put together my tremolito pedal with no issue (other than it having a slight buzz). I hope I can figure this guy out.

Switched out the op amp and now it is working great. Thank you for the help!

I'm not sure if the part wasn't working to begin with or if I somehow mishandled it and damaged it. Either way, it is working now. Two pedals working great now, with another coming soon!

Glad to hear that the new IC did the trick. Enjoy!

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2