Mutron Phasor not phasing

[Joe Kramer]

I just repaired a Phasor II, and the problem was the same as several other posters have said, bad solder joints.  On mine, from the trace side of the PCB, the solder beads around the pot legs looked okay, but in fact they weren't making contact.  This is because the legs are just barely long enough to reach the PCB, allowing only about 1/16" for the solder to grab.  Problem solved by removing the old solder, then applying plenty of heat and plenty of new rosin-core solder.  Works AOK now.  

[BDuguay]

I will look into this possibility too, thanks!
B.

[BDuguay]

Well, it is common for such circuits to use the same dual op-amp for the input stage and output stages.  While not labelled as such, it makes perfect sense from a layout standpoint, that Mu-Tron would have done the same thing.  Is it possible for the half of the 4558 that forms the input buffer to be fine and the half that forms the output buffer to be fried?  I suppose it is remotely possible, just not likely.  To me, in my youthful naiveté, I would take that as a sign that there is an issue with continuity on the input side of that mixer stage, OR the utput side.

Another avenue which I don't think has been explored is whether the Depth switch is making good contact.  In the absence of a scope, crank up the speed to max, so that you get a good steady peak voltage, and measure the AC voltage at the common of switch 2 over the various depth settings. 

I did this and got roughly the same readings from all 3 settings. That don't seem right, right?

[Mark Hammer]

I was going to say "No", but one would need to make sure it was being measured appropriately.

[psych60s]

Hello guys

I'm sorry to post in an old topic, but does someone still has the Phasor schematics? Beavis Audio is down and the only thing I can find is a bad quality scan of the schems, is this the same copy?

Thanks a lot!

[Derringer]

yup, just resolder EVERYTHING and you should be in business. Gently flexing the pcb in mine made the intermittent problems surface and disappear

I went so far in mine, a phasor II, as to run wire leads from the pot legs to their connections on the board, so that even when the pot lugs break free of the pcb, which they will - you are stepping on the thing after all, connectivity will remain.