Eml synthesizers

I just acquired an Electrocomp 200 with scratchy pots, and am looking for advice. The Allen-Bradley type J pots are fine, but the square cermet "mod pots" (modular potentiometers) did not survive the last few decades and can't be repaired because of the way they're constructed. For the ones that are just a single value I'm replacing them with other pots, but the problem is the two filter cutoff frequency controls, where a single shaft simultaneously turns two pots of different values (100k and 1meg). I can't find any new old stock, and to have replacements custom manufactured by potentiometer.com would cost $45 each with a $50 low volume fee and $15 shipping, so that sounds like a last resort. Anyone else have suggestions?

-thomas

Somewhere out there is a sheet that tells you how to do all sorts of things to pots by adding resistors. You could start with a dual 1 meg, add the resistors to one to cut it to the value you need. I'll try to see if I can find the sheet that I printed out long ago.
RigEML 500 

     On Tuesday, February 17, 2015 10:53 AM, "'Mr. Fang' thomas.fang@... [emlsynth]" <emlsynth@yahoogroups.com> wrote:
   

     I just acquired an Electrocomp 200 with scratchy pots, and am looking for advice. The Allen-Bradley type J pots are fine, but the square cermet "mod pots" (modular potentiometers) did not survive the last few decades and can't be repaired because of the way they're constructed. For the ones that are just a single value I'm replacing them with other pots, but the problem is the two filter cutoff frequency controls, where a single shaft simultaneously turns two pots of different values (100k and 1meg). I can't find any new old stock, and to have replacements custom manufactured by potentiometer.com would cost $45 each with a $50 low volume fee and $15 shipping, so that sounds like a last resort. Anyone else have suggestions?-thomas  #yiv0740107491 #yiv0740107491 -- #yiv0740107491ygrp-mkp {border:1px solid #d8d8d8;font-family:Arial;margin:10px 0;padding:0 10px;}#yiv0740107491 #yiv0740107491ygrp-mkp hr {border:1px solid #d8d8d8;}#yiv0740107491 #yiv0740107491ygrp-mkp #yiv0740107491hd {color:#628c2a;font-size:85%;font-weight:700;line-height:122%;margin:10px 0;}#yiv0740107491 #yiv0740107491ygrp-mkp #yiv0740107491ads {margin-bottom:10px;}#yiv0740107491 #yiv0740107491ygrp-mkp .yiv0740107491ad {padding:0 0;}#yiv0740107491 #yiv0740107491ygrp-mkp .yiv0740107491ad p {margin:0;}#yiv0740107491 #yiv0740107491ygrp-mkp .yiv0740107491ad a {color:#0000ff;text-decoration:none;}#yiv0740107491 #yiv0740107491ygrp-sponsor #yiv0740107491ygrp-lc {font-family:Arial;}#yiv0740107491 #yiv0740107491ygrp-sponsor #yiv0740107491ygrp-lc #yiv0740107491hd {margin:10px 0px;font-weight:700;font-size:78%;line-height:122%;}#yiv0740107491 #yiv0740107491ygrp-sponsor #yiv0740107491ygrp-lc .yiv0740107491ad 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A 110Kohm resistor in parallel with the outer lugs of one 1M pot will give you a total resistance of 99.09Kohm.

 

Peter

From: emlsynth@yahoogroups.com [mailto:emlsynth@yahoogroups.com] 
Sent: February 17, 2015 1:53 PM
To: emlsynth@yahoogroups.com
Subject: [emlsynth] EML 200 pot replacement

 

  

I just acquired an Electrocomp 200 with scratchy pots, and am looking for advice. The Allen-Bradley type J pots are fine, but the square cermet "mod pots" (modular potentiometers) did not survive the last few decades and can't be repaired because of the way they're constructed. For the ones that are just a single value I'm replacing them with other pots, but the problem is the two filter cutoff frequency controls, where a single shaft simultaneously turns two pots of different values (100k and 1meg). I can't find any new old stock, and to have replacements custom manufactured by potentiometer.com <http://potentiometer.com>  would cost $45 each with a $50 low volume fee and $15 shipping, so that sounds like a last resort. Anyone else have suggestions?

-thomas

As an update, I was able to spray some control cleaner into the guts of the mod pots (after removing their 4 screws and back plates) and their performance improved. It was a relief not to replace anything!

My next question, a long shot: does anyone want to part with a wooden lid for the 200, or have an extra one for some reason? Mine was lost by a previous owner.

i want a replacement lid too!
lol. NEW ALLIANCE EAST!!!!

--------------------------------------

New Alliance East - Mastering
New Alliance East - Facebook

X :::: B :::: S 

     On Friday, February 20, 2015 1:27 PM, "'Mr. Fang' thomas.fang@... [emlsynth]" <emlsynth@yahoogroups.com> wrote:
   

     As an update, I was able to spray some control cleaner into the guts of the mod pots (after removing their 4 screws and back plates) and their performance improved. It was a relief not to replace anything!My next question, a long shot: does anyone want to part with a wooden lid for the 200, or have an extra one for some reason? Mine was lost by a previous owner. On Feb 17, 2015 12:53 PM, "Mr. Fang" <thomas.fang@gmail.com> wrote:

I just acquired an Electrocomp 200 with scratchy pots, and am looking for advice. The Allen-Bradley type J pots are fine, but the square cermet "mod pots" (modular potentiometers) did not survive the last few decades and can't be repaired because of the way they're constructed. For the ones that are just a single value I'm replacing them with other pots, but the problem is the two filter cutoff frequency controls, where a single shaft simultaneously turns two pots of different values (100k and 1meg). I can't find any new old stock, and to have replacements custom manufactured by potentiometer.com would cost $45 each with a $50 low volume fee and $15 shipping, so that sounds like a last resort. Anyone else have suggestions?-thomas