Magnetron Time Expression Pedal

[MacGuffin_]

Trying to add a way to control time with a expression pedal without it totally borking the LFO. So far I have 2 ideas how:

1) Switched jack to disconnect the time pot entirely. This one may mess things up if it disconnects anything entirely before re-connecting on the exp side.


2)Non switched jack as a voltage divider? (This one was suggested to me by someone much smarter than I). Taking in the regulated 2.5v into the ring (maybe I want the 5v idk, read that most pedals don't like above 3v). I am sure I didn't set this one up right. The idea for this one is that it won't touch the LFO are below the time pot and (theoretically, if time pot is up high) wont mess up the time all that much?


Any advice/ideas on which route is better/less scuffed? I really just want that weird "tape speed" effect you get when modifying time on the fly.

 

[jcpst]

I would expect that this works:

Expression Control Wiring - PedalPCB Wiki

wiki.pedalpcb.com

At least, that’s what I’ll be doing on an upcoming build. If someone knows there is a problem with that, I’d be curious to hear.

 

[MacGuffin_]

I would expect that this works:

View attachment 93150

Expression Control Wiring - PedalPCB Wiki

wiki.pedalpcb.com

At least, that’s what I’ll be doing on an upcoming build. If someone knows there is a problem with that, I’d be curious to hear.

Same, that was my original plan (the first picture). But I was advised that it may break the LFO when plugging/unplugging the expression pedal. Wanted to get some other opinions. That design is also dependent on your EXP pedal having a 50k pot, some are 10k to 100k, the v_div is supposed to make that not a issue

 

[MacGuffin_]

After reading more docs (again). It looks like the VCO reference voltage is 2.5v, so connecting it like I did in the 2nd example should work, I think. But place the 2k resistor on the sleeve side to help prevent over-voltage if someone plugs in a TS cable instead of TRS