Hello everyone:
Need some help debugging an MXR Phase 45/DOD 201...
-Ordered the PCB from Tonepad.com
-soldered on all of the components (with the part substitutions for the DOD 201)
-the effect does passes signal
-the effect seems to be working but with no oscillation. For example when I rotate the Speed knob from one extreme to the other the effect goes from thin to bassy. If I do it real fast, I can hear the phasing occur. My inexperienced guess would be that the LFO is not working.
Any suggestions at all would be greatly appreciated. This one is driving me nuts!
Thanks.
Read this, especially the part about matching JFets.
http://www.lynx.bc.ca/~jc/pedalsPhase45.html
Regards
RDV
Thanks, but unfortunately I've already tried this. I've tried a dozen different transistors but the effect seems to behave the same way regardless.
Which JFets did you use? Because 2N5952 have an opposite pinout from the Tonepad layout. TP's layout will work with almost every other JFet.
Check out this thread:
http://diystompboxes.com/sboxforum/viewtopic.php?t=20038&start=0&postdays=0&postorder=asc&highlight=2n5952
Regards
RDV
I am using J113 transistors (like the original DOD 201). I already checked: the pinout is right for the Tonepad layout.
Any other ideas?
If your speed control is causing it to phase manually then you've made a boo-boo somewhere and you're just going to have to compare what you've done to the printed T.P. layout really carefully and find where it went wrong.
Good hunting
RDV
Thanks for all of your help RDV. Anyone else out there want to give it a shot?