I put together a new Egodriver. I tested the circuit and it sounded perfect. I boxed it and I've ran into some problems. I had to get a bit aggressive on boxing this guy so I may have wounded it. Here are the problems:
1.) It pops when switched on. But ONLY WHEN the volume on the pedal is turned up.
2.) I powered up the pedal with all the controls at zero. I brought the volume up and there was some crackle. I brought the gain up and there was a high pitched squeal. I brought the tone up (just a fraction from zero) and the squeal went away.
3.) With the volume and gain turned up the gain sounds very rough and does not sustain very long. The first initial not struck sounds great but the sustained note deteriorates quickly and sounds bad as it cuts out.
Could it just be a bad/broken pot?
(http://i980.photobucket.com/albums/ae285/guyskankrye/IMG_4367.jpg)
This thing was SO tight to fit together. I hate to take it back apart. :P
Try re-flowing your solder joints at the mounted pots.
Josh
Quote from: gtr2 on November 07, 2011, 11:28:31 AM
Try re-flowing your solder joints at the mounted pots.
Josh
Will do. I only have to wait 8 hours before I get to try this. Stupid work gets in the way of EVERYTHING!
Check the voltages around the IC again. Sounds like it may be mis-biased. Crackle usually means you have DC current flowing through the pot, so maybe a short between one of the pots and ground or another part of the circuit.
Okay...figured it out. The pins on the board mounted pots are touching.
I put double side tape between them but apparently the tape is conductive. I'm going to try to put some electric tape between them tomorrow. I'll have to pick some up though. I'm out.
What are some other options other than electric tape?
Pins touching eachother? I would recommend de-soldering them and putting some heatshrink tubing over the pins, allowing space at the ends for the solder connection to the pcb, then resolder them back in. The heat of the solder connection should shrink the tubing on nice and tight, but you can give it a tickle with a heatgun too, if required.
I also use a lot of double-sided foam tape in pedals, but rarely any electrical tape.
Quote from: nzCdog on November 08, 2011, 02:10:48 AM
Pins touching eachother?
Yeah...the "Volume" pins where pinched into the "Gain" pins. I miss drilled my holes and had to get creative.
I've recently been coating with just a bit of superglue gel. It dries clear and barely visable but works as insulation. Hot glue was messy and would peel right off. Of course heatshrink is professional but sometimes it's just to hard to get a little piece of heatshrink to cover a small connection.