slide pot question: eh micro synth

ian87 · November 20, 2003, 12:20:42 PM

hi, all.

here's my conundrum: i'm rehabbing an EH Micro Synth with 5 messed-up slide pots. the pots work, but the shafts are sheared off and i'd like to replace them. i can get replacements from EH, but they have a $75 minimum order, and 5 pots @ $4 doesn't get me close.

so i'm looking at mouser, and they have Alpha 100k slide pots that look right: either 312-9000-100 (audio) or 312-9100-100 (linear).

do those sound right to you? and which taper do i want??

thanks in advance for your help!

-ian

petemoore · November 20, 2003, 01:10:54 PM

I've thought that one could tell the diff between audio and linear by turning the knob with the DMM clipped to it ...you should be able to notice a much greater difference in the amount of R change at one end of the shafts rotation on an audio [linear, the numbers increase more evenly on the DMM through the range as you slowly, evenly turn the shaft]]...watch the meter start whippin fast at one end and slowly at the other as the shaft is rotated...or slid in this case.
EH might be able to help you with just that question of pot tapers on there...pretty sure I did this once...pins 1&2 to one DMM lead, pin3 of the pot to the other DMM lead, or accord the DMM hookup to whatever arrangement they're using in your pedal.

ian87 · November 20, 2003, 01:13:09 PM

cool, thanks for the info, pete!

-ian

ian87 · November 20, 2003, 01:40:29 PM

anyone else? i'm itchin' to place my Mouser order....

drew · November 20, 2003, 02:57:18 PM

Do you have a model number, manufacturer, etc. for the slide pots? You may be able to get a part number off it and if you can't find a direct replacement in mouser or digikey, search on the net and find an equivalent.

drew
toothpastefordinner.com

Bill Bergman · November 20, 2003, 03:17:19 PM

I'm tring to remember, I think they are linear. I bought some when I built mine but ended up using regular rotational pots.

ian87 · November 20, 2003, 03:25:14 PM

hey drew -- i tried mouser, but they didn't cross. it's a 25-yr-old CTS part, so i'm really not surprised.

thanks, bill! i'm gonna take a gamble and try linear.

-ian

Bill Bergman · November 20, 2003, 03:36:10 PM

Yep, they are linear. I just found the schematic. Good luck, it's a cool pedal!!!

ian87 · November 20, 2003, 04:55:01 PM

awesome, thanks for confirming that, Bill! can't wait to restore it to its former glory.

bwanasonic · November 21, 2003, 02:25:59 AM

Man I miss my EH Micro Synth. If you'd like to hear a tune featuring extensive use of it:

http://home.earthlink.net/~bwanacentral/sonic/fingersym.mp3

I used it both as *lead* and *bass* synth sounds. Circa the late 80's. Oh, and pretty much all the tracks are backwards.

Kerry M

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slide pot question: eh micro synth