Need ID on console power amp please

[OldGuy99]

Greetings all. Thinking to have a go at restoring this old power amp that was pulled from a console, but I’m afraid that’s all the info I have on it. Power tubes are four 6BQ5’s if that helps, can’t read any numbers on the preamp tubes. I can find no identifying marks or stamps on the chassis at all.
Look familiar to anyone with its distinctive copper colored chassis? Worth restoring?
Very much appreciate any info offered.

 

[fxer1982]

Greetings all. Thinking to have a go at restoring this old power amp that was pulled from a console, but I’m afraid that’s all the info I have on it. Power tubes are four 6BQ5’s if that helps, can’t read any numbers on the preamp tubes. I can find no identifying marks or stamps on the chassis at all.
Look familiar to anyone with its distinctive copper colored chassis? Worth restoring?
Very much appreciate any info offered.View attachment 3449850View attachment 3449851View attachment 3449852

flip it over to see the under side drop a photo of that too. the output transformers are made by Magnetic windinds divison, essex wire corp. easton pen... at times i pull a tube look through the tube and can make out number of the tube as i spin it slowly from the opposite side of the tube close to a bright light...the two transformers are different in the wire count and size...352 is manufacture 939 wire count, the other is 352 manufacture 943 wire count shouldnt make much sound different..

 

[gadget73]

Thats not wire count, its the manufacture date. Week 39, 1959 and week 43, 1959. The part number will tell you if they are the same or not.


don't specifically recognize it, but its an enormous power transformer. Honestly its a little difficult to really screw up a push-pull 6bq5 amp so its probably worth some fresh caps at least. Hopefully the transformer part numbers match. Once in a while you'll find an 000 or an 010 as the last 3, thats usually just a lead length difference.

 

[OldGuy99]

Thanks for having a look and weighing in guys.
Pic of underside attached, anything noteworthy?
Also attached better pic of top of output transformers. As you can see, numbers match save for the last digit, so perhaps noting a 'non-electrical' difference as you suggest? And when you say "it's a little difficult to really screw up a push-pull 6bq5 amp", I'll try not to take that as a challenge. Thus far I successfully restored a Magnavox 175 and Magnavox 8802, but they were both easily over a decade ago. The 175 still serves me well as part of my main system.
This amp seems a little less straight forward in terms of how many extraneous leads it has coming off it. Though I think I can figure out which ones I can discard, a schematic would save some guesswork.

 

[gadget73]

Hopefully. Hard to say for sure but if the core size is the same, its pretty unlikely the transformers are different in any meaningful way.

I meant that more in a design sense. A 6bq5 amp doesn't need a very complex driver circuit or any overly fussy design criteria so unless they just completely missed the mark its unlikely to be terrible.

Looks like its not one small tube per channel. The tube closest to the edge of the chassis looks like voltage amp for both channels, so the next one over has to be the inverter. I can see both input leads going to the outboard tube, as well as the feedback. That tube is cap-coupled to the next one over with the disc caps. I think its a split load inverter but not 100% on that.



black leads on the transformer are usually the primary, so expect that to be the power cord and/or switch leads. Blue is usually a 6v heater winding, so that shouldn't be needed. The orange and red coming out the other side by the input jacks tie into the HV filter cap, those shouldn't be needed either.

someone has been in here to replace the coupling caps already. Looks like you could probably throw in a set of electrolytic caps and fair bet this would just work.

I might make a small tweak to the speaker terminals for pure convenience though. From the bottom side going L to R it looks like ground, nothing, channel 1 output, channel 2 output. I might shuffle that around so you get ground, channel 1, ground, channel 2. Won't make a bit of functional difference, it just makes the speaker connections more obvious and convenient rather than having to share a terminal while one does nothing at all.

 

[mrwood200]

Google points to this being a Westinghouse amp -
https://audiokarma.org/forums/index.php?threads/unknown-el84-from-ebray-pics.149012/
https://www.ebay.com/itm/153262490503

 

[Patrick620]

Westinghouse was my first guess. They used a lot of that copper colored clad on their chassis.

 

[cademan]

That over sized power transformer tells me that there was probably a tuner preamp. That amp all by itself does not need that much current that that transformer probably provides.

The multi-colored wires coming from the chassis is also a tell tale sign of a possible preamp and/or tuner.

 

[OldGuy99]

@gadget73 Thanks for looking it over again and huge thanks for the breakdown of the extra wires. I was medium confident on sussing out the main power leads going to the power transformer, everything after that would have been guesswork. I have some OK speaker terminals bought long ago, so once I get it tested out I’ll install those, as well as a switch and fuse, then dress it up a bit with a nice wood frame.

@Patrick620 and @mrwood200 thanks for the info, The links are a big help. I’d googled Westinghouse but never did come up with an exact match.

I‘ll get some caps ordered and installed, then bring it up nice and slow on the variac.

 

[OldGuy99]

That over sized power transformer tells me that there was probably a tuner preamp. That amp all by itself does not need that much current that that transformer probably provides.

The multi-colored wires coming from the chassis is also a tell tale sign of a possible preamp and/or tuner.

Yes, I believe that is correct. The whole console was headed for the dump. I pulled the power amp and sent the rest on its way. This was several years ago.