Build Your Own Clone Message Board

Hi, having a lot of trouble with this build. I've rewired all the wires, checked the joints and components and can't seem to find the problem. Essentially when the pedal is engaged I have no sound, in bypass I get the normal dry signal running through to the amp fine. The LED works so I know power is getting to the board. I have had the occaisional flare of distorted signal when the pedal has been engaged an have played around with the trim pot at all points but have had no luck in getting a proper chorus sound and it's almost always silent. When the distorted signal comes through it only lasts a few seconds then fades out to silence.

Below are the voltages recorded for the pins on each chip and below that should be the pictures. Note that these voltages were recorded with the trimpot all the way clockwise, in the other direction the voltage drops considerably. When the trimpot is a little less than halfway turned the voltage on Pin 1 of the Op Amp is something like 0.7V:

IC TL022
Pin 1 = 4-4.5V (seems to cycle up and down)
Pin 2 = 4V
Pin 3 = 4.3V
Pin 4 = 0
Pin 5 = 3.9-4.7V (cycles)
Pin 6 = 4.3V
Pin 7 = 3.5-5V (cycles)
Pin 8 = 8.6

IC 3207
Pin 1 = 0
Pin 2 = 4V
Pin 3 = 0.7V
Pin 4 = 7.9V
Pin 5 = 8.4V
Pin 6 = 4V
Pin 7 = 4.14V
Pin 8 = 4.14V

IC 3102
Pin 1 = 8.4V
Pin 2 = 4V
Pin 3 = 0V
Pin 4 = 4V
Pin 5 = 0.3V
Pin 6 = 8V
Pin 7 = 2.8V
Pin 8 = 7.9V

IC Dual Op Amp
Pin 1 = 1.4V
Pin 2 = 1.3V
Pin 3 = 0.75V
Pin 4 = 0V
Pin 5 = 1.2V
Pin 6 = 1.3V
Pin 7 = 1.4V
Pin 8 = 8.6V

I should note that I have tested this in the enclosure and outside it - not on the metal table obviously

I suggest going back over your soldering again. Any solder joint where you can still see the solder pad or the hole that the lead comes thru the PCB needs to be re-soldered.

Also, there's a spot on the very right-hand side about one third of the way up from the bottom where there might be a possible solder bridge between two components...

This is a sure sign of a short or bad solder connection. Whenever you have intermittent operation, the problem is typically one component shorting out to another component, or a bad solder joint making intermittent contact with something. The solution is to make sure all of your solder joints are good. Here's a couple of quotes from the Simple Debugging page on DIY Stompboxes which I've found helpful in the past:



Your soldering does not look very even. Some joints are starved like Stephen said, many other are misshapen like they weren't hot enough. Make sure your soldering iron tip is clean shiny and hot. Also, use some acetone or alcohol and an old toothbrush and scrub the pcb to clean up all of the flux and solder residue; that stuff can conduct sometimes.

Thanks a lot for the replys. I took the whole thing apart, replaced all the components bar the chips and made sure that each joint was soldered properly bottom and top. My mistake was thinking that covering the pad on the bottom of the board was sufficient, not realising there were copper connections on top as well. Anyway the pedal works great now except for that ticking sound that many have complained about. This isn't an issue for me because my compressor in front gets rid of it.

Cheers

Covering the solder pad on the bottom of the PCB only IS sufficient. You had several solder joints on the bottom of the PCB that were solder starved that needed to be re-soldered.

All BYOC PCBs have plated thru holes so no matter how good you are at soldering some solder is bound to leech over to the component side. That being said there is no need to solder a component on both sides of the PCB.

The ticking you hear can be corrected by doing the following...

Remove the wire between the input jack's TIP lug and the PCB's IN eyelet. Now remove the wire between lug 4 of the stomp switch and eyelet 4 on the PCB. Now run a new wire from the input TIP lug directly to lug 4 of the stomp switch.