Old fender bypass caps rebuilding???

[Satamax]

Hi everybody!

Well, i'd like to "rebuild" old malory multisection bypass caps, fitting new caps in the old caps casing, has anybody done this and how did you do it???

Thanks a lot and best regards.

Max.

[stokes]

You would have to empty the old can and then find caps that will physically fit inside the can,not very practical.You may get 2 of the newer caps to fit in there but fitting 3 will not likely happen.

[Satamax]

Hi Stokes!

Thanks a lot for your reply. Well, i was thinking this. It's a messy job, i had phillips (iirc!) 22µ 40V which were laying around, and they would have fitted, but thought, why the heck! Anyway, it's been modified before changing PS caps! So they went in as they are. I might try the trick one day. If ever someone has few pics of the process.

Thanks again Stokes.

Bye.

Max.

[R.G.]

Hi everybody!

Well, i'd like to "rebuild" old malory multisection bypass caps, fitting new caps in the old caps casing, has anybody done this and how did you do it???
Max.

I have done it. It's really only worth the trouble if you are maniacal about preserving the original look.

I drilled through the end of the disk at the terminal end with a 1/4" drill bit, broke out most of the rest of the disk and pulled out the stuffings.

Here's something you may want to consider.

I have this concept I call the "Immortal Amplifier". Other than tubes, only the electro caps and controls (pots and jacks) have a wear-out mechanism. Why not replace the caps with AC motor-run caps made of polypropylene film in oil? These are available in 5uF to 50uF capacities at up to 440Vac rating. The DC rating of the cap is the value of the peak AC, so a 370Vac cap is good for 370*1.414 = 533Vdc. The 440's are good for 622 Vdc. They are tough, intended for lots of current passing through them, and probably better in terms of low ESR and low leakage than electros. They will last longer than the rest of the amp.

They are about twice the cost of electros, and much bigger. But if you go to an air conditioning supply store, you can get them cheaply, perhaps even cheaper on ebay.

It's a thought, if you're into recapping. Do it this way and never again.

[stokes]

Max,I just realized you are talking about bypass caps,I have never seen multisection bypass caps in a Fender preamp,I suspect they arent stock to begin with.Besides they are inside the chassis,I thought you were talking about the multisection can caps that sit on the top of the chassis in view.

[Tom Phillips]

Dual section cathode bypass caps are stock in many old Fender amps. Here's a pic from a 1964 Bassman showing the caps for those readers who may not know what we are talking about. I guess the confusion above was the "multi" description.

I have saved lots of these with the plan to re-build them for restorations but so far no one has pushed me to do it.

Tom

[Satamax]

Hey Stokes!

Same ones that Tom is talking about I have my be thirty or more in my workshop.

R.G. THanks a lot! You know what, i even have some in the workshop, i used to run an old dewalt three phase 208V radial arm saw on single phase 220 (we have ~240 now and 400V Δ )

[Albert Kreuzer]

Hey Max,

F&T in Germany makes double axial caps 2 x 25µF/25V.
Look here (scroll down):

http://www.die-wuestens.de/eindex.htm

But maybe you want to preserve the original look...

HTH
Albert