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 Post subject: Rca? Magnavox? Ampex? Vintage Console Amplifier.
PostPosted: Jun Mon 25, 2018 6:02 am 
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Joined: Apr Sun 09, 2017 4:50 am
Posts: 9
Hello All! :)

A Little Backround..
Just about 40 Years Ago, When I was about..16,
My then Girlfriends Parents purchased a New, "Modern" (at the time) Zenith Console.
Complete with Phonograph, Am/Fm Stereo, Cassette, and 8-Track!
well, long Story short, I was "gifted" with their old stereo Console. :D
(which might have been a Phono-only Console (I do not exactly recall)
I was, at the time, (and still am) into Guitars and Tube Amps.
and all I wanted was to strip the unit for parts for when my increasing "Electronics Experience" was enough for me to be able to convert this new found toy to a useable guitar amp.
well..that didnt happen, (until more recent years) and the amp got relegated to the crawlspace in my parents home.
Move Ahead to just three years ago, when we were selling the house, I went up in the crawlspace and found this old Amp.
but, for the last few years it has sat in my storage.
but Recently, I realized that it would make a Fine stand-alone Stereo tube amplifier.
and I have begun Setting it up, Updating And Modifying It as such.
I'm pleased that the overall circuit and layout are fairly Simple and Straight forward.
but Still, I would Love to Have The Schematic For The Amp.
I have pretty much identified All of the Components. and, Have a Clear Idea of what to do.
Still, A Schematic diagram Never hurts.
the Problem: I have Searched Photos Online until my eyes Ache..
and only Once did I find an Amp that Resembles my amp Exactly. and that amp was also Modified as a Stand-alone Amp.
it was Listed as Being "RCA W/Triad Output Transformers". But I just Don't feel that this is correct.
I have found "Similar" units that have been made by Motorola, Ampex, Magnavox, but none are really close enough.
the Unit uses the a quad of the somewhat rare and expensive 6973 tubes, with each channel having a 6AN8 driver tube. and a 5U4 rectifier tube.
I have honestly searched for some backround as well as a schematic for this unit. But, Sadly, I have failed.
and So, I decided to Share it here in order to possibly find a clue to its Manufacturer.
Thank you in Advance to Any And All who Offer info on identifying this Amplifier.


Attachments:
tube amp1.jpg
tube amp1.jpg [ 14.02 KiB | Viewed 1090 times ]
tube amp 2.jpg
tube amp 2.jpg [ 23.51 KiB | Viewed 1090 times ]
tube amp3.jpg
tube amp3.jpg [ 14.99 KiB | Viewed 1090 times ]
tube amp 4.jpg
tube amp 4.jpg [ 21.33 KiB | Viewed 1090 times ]
File comment: just starting to clean..
tube amp 5.jpg
tube amp 5.jpg [ 17.44 KiB | Viewed 1090 times ]
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 Post subject: Re: Rca? Magnavox? Ampex? Vintage Console Amplifier.
PostPosted: Jun Mon 25, 2018 3:09 pm 
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Joined: Sep Tue 30, 2014 6:08 am
Posts: 4622
Location: Norfolk, VA
Any markings on the transformers and can caps? Part numbers can lead to manufacturers, and then to a schematic.....

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Brian
"Capacitor Cosmetologist since 1979"
USN Retired 1984-2006 (Avionics/Cal)


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 Post subject: Re: Rca? Magnavox? Ampex? Vintage Console Amplifier.
PostPosted: Jun Mon 25, 2018 4:59 pm 
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Joined: May Sat 06, 2006 4:03 am
Posts: 3450
Location: ZIP 23831 South of Richmond, VA 25 miles down the pike.
What about the remains of console, cabinet, the back, any thing on it with model numbers? No chassis number or part of a number?

Bill J.


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 Post subject: Re: Rca? Magnavox? Ampex? Vintage Console Amplifier.
PostPosted: Jun Tue 26, 2018 8:05 pm 
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Joined: Apr Sun 09, 2017 4:50 am
Posts: 9
Sadly, the console was stripped (by me) :x back 40 years ago when I first received the unit. :(
And, not many parts have any kind of name or part info on them.
No part #'s on the chassis and no numbers on the power tranny.
The output transfomers are made by Triad. But not much comes up on a web search.
One of the metal can caps is made by Astron.
No info other than voltage and ratings on the larger one.
Thankfully, the Circuit is not very complex or crowded underneath.
I did see a very similar Amplifier unit made under the Symponic brand name. But, it had different outputs transformers. (Or at least they had the metal covers on them anyway)
Apologies for the upside down pictures..
( I'll guess the only way to fix them is to delete them and re-upload again?)
Thanks for the Viewing, and thanks for search ideas. :)


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 Post subject: Re: Rca? Magnavox? Ampex? Vintage Console Amplifier.
PostPosted: Jun Tue 26, 2018 9:16 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 14725
Location: Fernandina Beach, FL
I was waiting for other responses first. As I look at the bottom of the chassis, I suspect within a few minutes, you could just draw the schematic. There are not very many components in that chassis.

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Don


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 Post subject: Re: Rca? Magnavox? Ampex? Vintage Console Amplifier.
PostPosted: Jun Wed 27, 2018 9:50 pm 
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Joined: Jun Sun 14, 2009 10:44 pm
Posts: 456
That amp looks very familiar!

Though (to me) appears the output transformers have been switched out. Take a look at this post/inquiry I placed here about 2 years ago:

viewtopic.php?f=13&t=309085

Was the console you took apart similar? 'Have same issue in that there was no clear labeling. The discussion led to some possibilities but not a firm conclusion.

Good luck and 'will be watching for any new developments!

Cheers,
Grid2


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 Post subject: Re: Rca? Magnavox? Ampex? Vintage Console Amplifier.
PostPosted: Jun Thu 28, 2018 2:26 am 
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Joined: May Sat 06, 2006 4:03 am
Posts: 3450
Location: ZIP 23831 South of Richmond, VA 25 miles down the pike.
"The output transfomers are made by Triad. But not much comes up on a web search."

OK, any numbers aside from the Triad which are the end item manufacturer? Post the triad and any other numbers.

Bill J.


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 Post subject: Re: Rca? Magnavox? Ampex? Vintage Console Amplifier.
PostPosted: Jun Thu 28, 2018 5:13 pm 
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Joined: Nov Wed 27, 2013 5:59 am
Posts: 668
Location: Metzger Oregon
You could draw a schematic as Don suggests, if you know what tubes were used. Are there any markings as to the tube types? If not, you might need to measure the transformer turns ratio and make an educated guess.


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