Seeburg Symphonola 147

[Cid]

Not sure if you guys will be able to help, but I figured its worth a shot. I'm currently in the procces of trying to recap the MA1-L6 Master Amp in my Dad's old jukebox. Its had a crackling noise for years that the previous owner had attributed to a blown cap, but I only recently got around to taking it appart. One of the big problems I've been running into is outdated markings on the caps (it IS over 60 years old after all!) I've only recapped motherboards and a couple of monitor power supplies so I was a little unprepared for the ratings I was seeing on them:

.10 M.F.D.
400 V.D.C.

and

CAP. D.C.W.V.
.01 1000

were a couple of the ones I saw inside. ( sorry for the lack of pix, my phone died while taking them)
I can only assume that "M.F.D." means "uF" but I'm not even sure what types of caps would be best to use. the origional caps were paper with wax covering them and I'd rather not accidentally "brick" something this old and valuable. Any advice would be apreciated!

[stj]

Re: Seeburg Symphonola 147

.1uf 400v
10nf 1kv

i suspect the second is ceramic

got foto's - i used to do jukeboxes.

[Scenic]

Re: Seeburg Symphonola 147

M.F.D. -> microfarad -> uF

[Cid]

Re: Seeburg Symphonola 147

Ok here's a couple of pix of the caps and the amp itself...

[stj]

Re: Seeburg Symphonola 147

start with the electrolytic screwed to the side of the chassis in the last foto.

[stj]

Re: Seeburg Symphonola 147

and clean or replace the rotary wafer-switch i can see in the upper-right.

[Cid]

Re: Seeburg Symphonola 147

Well I cleaned the switch (heres hoping I dont have to replace it!) As for the electrolytic attached to the chassis I was actually hoping to replace all the caps since most seem to be in poor condition though, only two seem to have burst open... I'm currently having an issue finding caps to match the requirements of the existing ones. I'm aware that the voltage can be slightly higher than the ones in there, but what about the capacitance? is there some sort of "margin of error"?

.01uF 1000v
.1uF 600v
.1uF 400v
.1uF 100v
.02uF 400v
20uF 25v
.5uF 100v
.001uF 600v

I usually only do business with Digikey, is there a more comprehensive source I should try instead? Also any brands I should try for (or stay away from)?

[stj]

Re: Seeburg Symphonola 147

the very high voltage stuff can be replaced by ceramics,
the others can use polyester or polypropylene.

the 20uf i'd use a 22uf electrolytic.
use something good like a panasonic FK series if pos.
atleast make sure it's 105' capable - those trays get pretty hot.

[Cid]

Re: Seeburg Symphonola 147

Thanks for all your help! I post my results when the parts arrive. Hopefully the worst of the electrical problems are behind me now!

[stj]

Re: Seeburg Symphonola 147

if you like pain, meter all the resistors.

[Cid]

Re: Seeburg Symphonola 147

Holy crap... I totally didnt think of that... this thing is mostly made out of resistors and they are probably all in need of replacement...

[stj]

Re: Seeburg Symphonola 147

probably not a problem with most, but ones that handle over 100v may have changed value.

[bentonbobcat]

Re: Seeburg Symphonola 147

Did you ever finish capping this amp? I am trying to do one now.

[Hemingray]

Re: Seeburg Symphonola 147

You can meter the resistors in this, but unless they're way out of whack, they're good to use.

Someplace in here there's gotta be a filter capacitor. May be a big silver can on top of the chassis. Usually found near the power transformer and rectifier tube. This cap is a MUST to replace in these, even if there's no hum.

As for the rest of the caps, You can always use Sprague Orange drops. They're quite decent in tube gear. (Having used these to recap antique/vintage tube radios myself).

Once recapped, this should sound excellent.