Help identifying this old amp

[Trick]

Anyone have any info of what this amp may be? I know it's at least 35 years old. I also have a 3/4 guitar that I believe it may have come with, there's no branding on the guitar at all.
This is the only thing I could find similar through searching: https://reverb.com/item/8318930-vint...e-kay-or-valco

Thank you!

[J M Fahey]

looks the same as the Reverb one.

Yes, most probably made by Valco - Kay,etc. , those were amp mills which made them for "catalog order" shop chains, basically same amp could be found under 20 different "house brands".

Small problem: not 35 y.o. but more likely well over 60

Large problem: it is a "widowmaker", it has NO power transformer so itīs DIRECTLY CONNECTED TO MAINS.

You NEED to add a 120V isolation transformer (US based Forum members will certainly suggest some available there) AND a chassis grounded 3 wire cable and plug.

I am currently repairing a same type KAY 703C amplifier and of course am doing exactly that.

Please post a couple guts closeups, and the tubes it uses, may help idīing it.

Some had a paper label pasted inside, showing tubes, model, maybe even manufacturing date, again useful.

I bet we can find one of its "brothers".

[Trick]

looks the same as the Reverb one.

Yes, most probably made by Valco - Kay,etc. , those were amp mills which made them for "catalog order" shop chains, basically same amp could be found under 20 different "house brands".

Small problem: not 35 y.o. but more likely well over 60

Large problem: it is a "widowmaker", it has NO power transformer so itīs DIRECTLY CONNECTED TO MAINS.

You NEED to add a 120V isolation transformer (US based Forum members will certainly suggest some available there) AND a chassis grounded 3 wire cable and plug.

I am currently repairing a same type KAY 703C amplifier and of course am doing exactly that.

Please post a couple guts closeups, and the tubes it uses, may help idīing it.

Some had a paper label pasted inside, showing tubes, model, maybe even manufacturing date, again useful.

I bet we can find one of its "brothers".

Thanks for that info! I attached some pics of the guts. It does have a 2 prong 120V plug, not sure it it's wired up correctly but know it's worked all these years that way. I had disconnected the speaker leads a while back and at one time used it to power a heil talkbox. This was handed down to me from my father so that's why I knew it was of at least a certain age. Hope the pics help provide some more details.

Tubes are labeled 12AX7A (Multivox), 50C5, 35W4 (Japan 3J)

[J M Fahey]

Looks quite clean (expected spiderwebs, rust, rat poo, cockroaches, not kidding) and I see some modern components such as "modern" resistors, light blue and yellow capacitors, but those 3 large cardboard electrolytics MUST go.

Not sure about your Electronics experience.

And in any case, youīll need tat iso0lation power transformer.
No doubt it worked as-is, itīs HAPPY with 120V Mains ... itīs us weak Humans who tend to malfunction or stop when subject to it.

EDIT: it might be one of these:
https://el34world.com/charts/Schemat...Schematics.htm

or:

https://el34world.com/charts/Schemat...Schematics.htm

or ........

[glebert]

Guts look really similar to this Dynavox 102, not that that helps too much. https://reverb.com/item/3881102-dyna...irl-grillcloth

That tube compliment makes me think it is basically the power and amplifier section of an All American 5 (AA5) tube radio.

[J M Fahey]

Yes, which was the basic setup foe widowmakers, simply because it was THE cheap made by the millions standard way back then.
Also used in record players, too weak fro PA duty.

Most I found use a single pentode preamp, but searching around youīll certainly find one running a 12AX7, and that will be very very close, if not the same.
Hey! Even revered Leo used 12AX7 with 100k on plate, 1k5 cathode bias .... STRAIGHT out of the RCA (and others) datasheet.

Those generic manufacturers didnīt want to design anything technically advanced or groundbreaking, just an easy to make well known product which would sell in quantity, so they basically used tube book datasheet examples, I donīt expect surprises there.

In fact you donīt have many components there (15-20?) so Iīd straight get good light, a pair reading glasses, pencil and paper, and start drawing what I find.

Start with something like this, and "fill in the blanks", add extra components you find and pencil lines connecting them.



Recheck and correct until it matches what you have, and then redraw in another sheet in a neater way.

Post what you find.:

[g1]

Some info about 'widowmaker' amps and how they can get you electrocuted: https://robrobinette.com/Widowmakers.htm

[Trick]

Thanks for all the info!