JCM800 2205 Dual Gang Pot Source

[misterc57]

I'm having a hard time finding a replacement dual gang 24mm A1M gain pot for a 4212 aka 2205.

Willing to do a solder lug but not finding anything with knurled split shaft.

Do not want to order from eBay and/or overseas.

My usual suspects (Tube Depot, Digikey, Mouser, amplified parts) have nothing in stock.

Read a similar 2013 thread " Source for replacement 1M dual gang pot for JCM800" with no results.

Any 2025 suggestions please?

Thank you, Mark

[The Dude]

The only place I can find them is on eBay. Why are you opposed to buying them from eBay? I wouldn't buy active components from eBay because of all the Chinese fakes, but you should be pretty safe buying pots.

[mozz]

Pots yes. Would question Alpha full size. Trimmers no, Bourns made in Mexico, shipping from China. Probably fake.

[misterc57]

Found none on eBay that are not in a foreign country and that one is about $36 with shipping and with "who knows what" the tariff may be that day could end up being double or triple that amount.

May end up buying a solder lug unit with solid shaft from Tube Depot. I may have a screw on knob that is similar to the "push on" and if not, "function over form".

Just curious... would a 500K do the job or create an issue?

Thank you

[mozz]

Buy one of each and swap out splines.
https://synthcube.com/cart/potentiom...-16mm-pc-mount
https://synthcube.com/cart/potentiom...-knurled-shaft

Dual 1 meg.
https://www.thompsonguitarandthrift....UIzYdMwqD9xZb6

Dual 1 meg
https://leeselectronic.com/en/produc...-16mm-pcb.html

Dual 1 meg
https://cricklewoodelectronics.com/P...eo-Log-1M.html

[g1]

May end up buying a solder lug unit with solid shaft from Tube Depot. I may have a screw on knob that is similar to the "push on" and if not, "function over form".

I would go with a 24mm solder lug version (just so the bushing fits the hole better) and a set screw knob. amprepairparts has singles of the knob.
Not sure what the bushing diameter is of the tubedepot pot, but amppartsdirect has both 1/4 and 3/8 inch bushing size for A1M dual pot.

[J M Fahey]

POST-THE-SCHEMATIC-HERE

If plain voltage divider type Volume controls, 500k is fine.

An extra problem with those pots is extra long threaded neck (which you will find nowhere) so best bet is buy whatever you get, even 16mm, bolt it to front panel, and use 1" long wires from lugs to PCB holes.

EDIT: IF you get a full length solid shaft, turn it down to *less* than proper size using a lathe or even a bench drill and a file, cut it to proper length and heat shrink it.
Knob internal knurls will bite into soft heat shrink "flesh" without damage.

Guess the amp pafrts one by G1 is the closest one.

[Chuck H]

Found this one:

https://www.ebay.com/itm/276487421817

Available through their own site too (as in not Ebay). Price is about the same with shipping. Looks like an Alpha pot to me. No way for my own experience I can be sure the pins line up exact and the bushing is of suitable length. But it does seem to be implied.

Looks like TAD has the same pot but it's more expensive. Also said to fit the 2205.

[misterc57]

Found this one:

https://www.ebay.com/itm/276487421817

Available through their own site too (as in not Ebay). Price is about the same with shipping. Looks like an Alpha pot to me. No way for my own experience I can be sure the pins line up exact and the bushing is of suitable length. But it does seem to be implied.

Looks like TAD has the same pot but it's more expensive. Also said to fit the 2205.

Saw that one but staying away due to price and unknown tariff

[misterc57]

schematic VR4A and VR4B

jcm800_splitch_50w_2205.pdf