Pre-war amp, not sure of make

[thelonious_crunk]

Hi all, new here. I came into possession of a combo amp. Looks pre 50s to me. I need help understanding what caps i can use in place for the older ones. Its gonna take some elbow grease to get this going but nice point to point wiring. Probably even an old PA amplifier with its 4 inputs. Any help would be greatly appreciated

[vintagekiki]

What is written on the back of the chassis, who is the manufacturer and possibly what model it is.

[Enzo]

The caps all look common to me, the film caps are all printed label types, as are the electrolytics. There are a few color codes resistors of the old body color plus dot codes, and there are plenty guides to that online.

[g1]

Just a reminder, in the real old stuff like that, MFD is microfarad. Modern term would be uF.
Modern mF you see in online catalogues today signifies millifarad, which did not exist (in manufacture) back then.

[thelonious_crunk]

The caps all look common to me, the film caps are all printed label types, as are the electrolytics. There are a few color codes resistors of the old body color plus dot codes, and there are plenty guides to that online.

Thank you. So what would be modern ones for the 12 film caps that are paper and 600v .01uf? Are they polystyrene?

[Jazz P Bass]

I would use orange drop caps.

Man do you have a tough row to hoe with that thing!!

[Enzo]

Any ordinary modern film cap. Those old caps are actually paper dielectric, I called them film just out of habit.

Orange Drops or Mallory, or whatever brand you like. Lots of guys use orange drops, I prefer the yellow Mallory caps just because they seem to have a smaller footprint, easier to line up on the board.. Also they have axial leads.

When they built it, they didn't use any special parts, it is just a guitar amp.

[glebert]

When they built it, they didn't use any special parts, it is just a guitar amp.

Not that it makes any difference technically, but I was wondering if this would be for guitar or more of a small PA thing, since it has four Gain controls (presumably one for each input jack?).

[Enzo]

Well USING it as a guitar amp. It could be a small PA or an accordion amp - much more common back then.

Looking at the photo, I see four inputs and four gain controls, I now I have to agree it is likely a small PA system. In any case, it was never made with fancy parts or any critical value parts.

PArt of why I say that is that those old parts often had values no longer standard. SImple changes sometimes, what used to be 0.05uf would now be 0.047uf 25k resistors would now be 22k or 27k.

[mozz]

Could you post the tube lineup? I have Rider's PA manual and it's probably in there if you find any name on it.

[thelonious_crunk]

Just a reminder, in the real old stuff like that, MFD is microfarad. Modern term would be uF.
Modern mF you see in online catalogues today signifies millifarad, which did not exist (in manufacture) back then.

Thanks i was reading that yesterday

[vintagekiki]

https://web.archive.org/web/20160330042723/http://theused.com/resource/

[thelonious_crunk]

Any ordinary modern film cap. Those old caps are actually paper dielectric, I called them film just out of habit.

Orange Drops or Mallory, or whatever brand you like. Lots of guys use orange drops, I prefer the yellow Mallory caps just because they seem to have a smaller footprint, easier to line up on the board.. Also they have axial leads.

When they built it, they didn't use any special parts, it is just a guitar amp.

Thanks, i went with Mallory since they look similar. I found all modern replacements for the caps. I even found Sprague for the other ones needed which were ones in this amp already. I solder on boards from 8 Bit computers often so it shouldn't be too much for me

[thelonious_crunk]

https://web.archive.org/web/20160330042723/http://theused.com/resource/

Is there a chance mine is in there if i look? Not a bad idea!

[thelonious_crunk]

Well USING it as a guitar amp. It could be a small PA or an accordion amp - much more common back then.

Looking at the photo, I see four inputs and four gain controls, I now I have to agree it is likely a small PA system. In any case, it was never made with fancy parts or any critical value parts.

PArt of why I say that is that those old parts often had values no longer standard. SImple changes sometimes, what used to be 0.05uf would now be 0.047uf 25k resistors would now be 22k or 27k.

Yeah i was thinking it was never really a guitar amp, but won't take much to make it one. I had a tube Sony Tapecorder reel-to-reel early 50s that sounded amazing with guitar direct in. This will go with my 40s Kamico archtop well.

But the guy was a Vietnam vet who sold it and said it was his wife's dads amp and he played a Gibson ES-175 through it for years. Still payed less than other tube amps local to me.