[DEBUG] MXR Phase 90 LFO doesn't oscillate. Help?

[drea]

Indeed, the thought had occurred.

I'm getting phasing with vBias between 1.6v and 2.8v. So I guess I could replace the 250k trimmer with a 50k pot, a 100k/120k from pin3 (or 1, I always get this backwards) to vRef and an 82k from pin1(3) to ground.

All assuming that my maths is right

[duck_arse]

those values look about near enough to my maths, we could both be wrong.

do you get a tonal difference across the range? I never bother with 1, 2, or 3, just ccw, c (or w), and cw. no confusions then.

[drea]

do you get a tonal difference across the range?

Yup, it's very different. At the bottom of the range it's a pulsed treble cut and a pulsed bass cut at the top. I guess it's down to which of the jfets are turned on/off across the bias voltage range.

I never bother with 1, 2, or 3, just ccw, c (or w), and cw. no confusions then.

The controls on the tubescreamer I built are volume, tone and cleanness, so I'll definitely give your method a try.

[duck_arse]

err, that's not the control names, it's the pot lug names. ccw=counterclockwise, w=wiper//c=centre, cw=well, you get the idea.

confusions still.

[drea]

I meant that I labeled the Drive pot "Cleanness" because it's wired as clockwise for clean and anti-clockwise for dirt.

[drea]

Got the reverse log pot and everything's right with the world.

Just waiting for some 120k resistors to come in now to get the trimmer onto the front panel. Slightly stuck for what to label it though. Presence? Spangliness?

[duck_arse]

baste?