Hi everyone,
Ok, got a pretty descent etch on the board, populated and tested, nothing. I found a couple bad solder points, now I have signal getting through the board, but no phasing!!! I've checked and rechecked the board until my eyes hurt. I cannot find any other bad solder joints or bridges and need a little help with debugging. The signal has some coloring to it as it is a bit different than bypassed but neither pot has any effect. Can someone point me to a good place/method to troubleshoot this thing?
Thanks in advance,
mike
If you've gone that far with it, run through the schematic and double check all of your component values esp. around the LFO section. One resistor of the wrong value can throw the circuit's operation waaayy off.
I had a couple that were giving me grief, and it turned out the chips were not seated in the sockets properly. Once continuity between IC pin and socket contact was established, everything worked fine. Cheap sockets will do that to you, and having three 16-pin chips on the board doesn't help.
Hi Mark and HP,
Actually you were both right! I went through all the values and had a resistor near IC 4 was wildly big. I switched that out and nothing, still had signal, but no phasing.
So I tested all the sockets using my meter and all of them had continuity to the board side. So I rechecked all the solder points and values again. Nothing. I got pissed and put it aside. On sunday I tried again and was testing the sockets but this time I tested from the socket to the next soldered componant. Finally, I found a broken trace to ground on the LFO. I soldered a jumper and that was it.
Thanks to you both for your help. I was going cross eyed looking at this thing and it was nice to have the direction!!
m.
Great to hear you got it going! Sometimes looking closely and testing every little bit of the circuit is needed to find the culprit. The Ross Phaser is one of my all-time favorites. I hope you have fun with it!
Hi LP,
I love this phaser. I built the small stone years ago and loved it, but not the volume drop. I was going to mod it with a linear power boost but decided to build the Ropez instead. Thanks again for your help.
mike