small diameter pot needed for black russian EH big muff pi

[blackieNYC]

One of the russian pots is destroyed.  the shaft is about 14mm long, and only 4mm in diameter.   Our usual US distributors don't seem to carry this pot. 
If I were to drill out the hole for a 16mm alpha, the knob of course won't fit.  And I can't match this particular chicken head.  Does anyone know where I can get 4mm diameter pots?   Or maybe I should drill out all three holes, replace three pots, and give the thing three new knobs?

[theehman]

Do you have any pics of the current pots?  I might have one.

[italianguy63]

I had to replace one too... for the life of me I can't remember where I got it... Sorry!

MC

[davent]

Could the knob's hole be enlarged to fit the standard 1/4"?

Digikey sell CTS pots with 1/8"/(3mm) shafts, a bushing, a wrap off thin brass around the shaft of one of those to increase the diameter to 4mm.

dave

[blackieNYC]

hollowing out the knob may be possible. the set screw is well away from the center.  But I'm hoping to find this pot:

[davent]

What value?

https://www.emma-music.com/-cts,us,4,MINI50B-SO-B50M62.cfm
dave

[smallbearelec]

Does anyone know where I can get 4mm diameter pots?   Or maybe I should drill out all three holes, replace three pots, and give the thing three new knobs?

Alan--

I have that CTS 100K pot with the 1/8" shaft:

http://www.smallbear-electronics.mybigcommerce.com/poteniometer-for-russian-big-muff-work-alike/

As Dave noted, a sheetmetal adapter would make it to fit. You could also replace all the pots with inexpensive Alphas and change the knobs to these:

http://www.smallbear-electronics.mybigcommerce.com/green-russian-bmp-classic-style/

I'm gonna be paying off the tooling for awhile so can't offer to get that chicken-head style made any time soon.

Now that I think about it, if you are willing to replace the knobs but want to retain the two original pots, these adapters

http://www.smallbear-electronics.mybigcommerce.com/knob-shaft-adapter-1-4-to-1-8/

would help. They can be tooled out easily to 4mm to fit the Russian pots. Then all the pots take a 1/4" knob.

Regards
SD

[blackieNYC]

Thanks Steve!   I missed those pots.  I'll order one and cut that shaft down to size.

[theehman]

I might have an original one to match if you'd post a picture.

[blackieNYC]

here's the back.  In the above photo you might see the D shaft.

[theehman]

here's the back.  In the above photo you might see the D shaft.

I have 3 pots which are from a Sovtek Big Muff.  None are exactly the same but you're welcome to one if you want.

[blackieNYC]

That's great!  I've sent you a PM.

[Dr. Satan]

http://www.smallbear-electronics.mybigcommerce.com/poteniometer-for-russian-big-muff-work-alike/