Phase 100: matchin' those trannies.....

[Bucksears]

Ok. I am waiting on the opto-couplers from Smallbear, but just started reading about the matching of the transistors. The Phase 100 takes 5 transistors, I'm going with all 2N5088's.
Do I need to match these? Would I use R.G.'s JFET matcher for that?
(sorry, never had to match transistors before)

Thanks,
- Buck

[Mark Hammer]

5088s are not JFETs.  To the best of my knowledge, the Phase 100 requires no transistor matching.  Your hunch was sort sort of on the right track since FET-based phasers usually DO need FET-matching to get optimum sweep feel, but in this case it is LDRs doing the sweeping, not FETs, and these don't have the same issues as FETs, hence no matching needed.

[Bucksears]

Thanks, Mark. Yeah, I didn't think they were JFETs, but wasn't sure if they needed to be matched for voltage or whatnot.
I have a huge smile on my phas....er, face, now.
Thanks again,
- Buck

[Fret Wire]

No BP trannies have to be matched, but the vactrols have to be matched for best phasing, just like the jfets do in a phase 90. Per the original MXR calibration procedure.

[RickL]

Calibration procedure? Do tell. This might explain why the one I built doesn't sound as good as my original.
Any idea of where I might find this procedure?

[Fret Wire]

Finally found where I had the hard copies (I don't have it on the PC). It's more involved than just setting the trimpot by scope or ear. There's several scope and voltage checks, plus possible regen adjustment (15k), and trimpot range (56k). There's also specific voltages for the led side of the vactrols. No wonder the reissues don't sound as good. I doubt they are doing the full set-up and checks.

I got my hands on a copy to rebuild an old block logo unit, it definately was a big help. I'm glad I got the copy before I built my own. I got the matched vactrols from here:
http://www.lsound.com/Parts.htm

If you want it, pm me, and I can scan them through an email.