Filmosound 285 conversion speaker jacks

[Johnny_March]

Hi. I picked up an original 50’s filmosound projector and I decided to convert it to a guitar amp. I just successfully converted a filmosound 385 and I thought this one would be similar in difficulty.

I ran into an issue I don’t know how solve. The speaker jacks on speaker this amplifier are very large. Physically, they are close to being the size of an XLR jack, or even the same size hole as a Fender pilot lamp.

I’ve tried looking for some washer that can sandwich in the larger hole and put a 1/4 jack into, but all the ones I can find are too thick to use.

Has anyone successfully converted these speaker jacks into 1/4 inch? Or is there some adapter that I can use? I’d appreciate any good advice. Thank you.

3C7831BA-C3D1-4D5D-829A-1D7EB88F0748.jpeg

[thetragichero]

maybe a little unconventional for a guitar amp, but i bet a couple of those speakon jacks with the 1/4" jack in the center would fit
the other option would be to just drill new holes for 1/4" jacks and leave the originals on for 'charm'

[ChopSauce]

Or rivet a plate drilled to the correct diameter.

[Stevem]

They look like cinch Jones jacks to me which where a Military type of connector, and used a lot for civilian gear also.
They can still be found if you look,

[jabguit]

Or rivet a plate drilled to the correct diameter.

What I would suggest....


cheers,

[maxkracht]

I added a brass plate to this one, think it only needed one extra hole drilled. I also considered using a multi pin connector from Tayda which has similar dimensions to the original plug, but new, inexpensive, and you can get both genders.

[Phil_S]

Some folks can't conceive of undrilling a hole, but it's done all the time. Nice job!