Discussion:
1964 Magnavox Astro-Sonic Schematic?
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g***@gmail.com
2007-08-21 19:27:08 UTC
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Any clue where to locate the schematics for a 1964 Magnavox Astro-
Sonic solid state (ugh!) console stereo? Model number is 2ST631,
Chassis R20507-00. Does a schematic exist? I've looked in all the
usual places I know of online...

Gerry
g***@gmail.com
2007-08-23 10:30:40 UTC
Permalink
Post by g***@gmail.com
Any clue where to locate the schematics for a 1964 Magnavox Astro-
Sonic solid state (ugh!) console stereo? Model number is 2ST631,
Chassis R20507-00. Does a schematic exist? I've looked in all the
usual places I know of online...
Gerry
I take it from the lack of replies that there are no schematics
available anywhere? I couldn't even find this beast on Sams
Photofacts....
vey
2007-08-23 12:12:03 UTC
Permalink
Post by g***@gmail.com
Post by g***@gmail.com
Any clue where to locate the schematics for a 1964 Magnavox Astro-
Sonic solid state (ugh!) console stereo? Model number is 2ST631,
Chassis R20507-00. Does a schematic exist? I've looked in all the
usual places I know of online...
Gerry
I take it from the lack of replies that there are no schematics
available anywhere? I couldn't even find this beast on Sams
Photofacts....
"on Sams Photofacts...."

You mean online? Not much there. In a different thread Robert Casey said:

Sam's has made a small side business of creating pdf's of old folders
for us hobbyists who want to fix that old vacuum tube TV set. You
basically ask for a specific folder from their database of model
numbers, then someone pulls the paper folder and scans it in to create
the pdf. It cost a bit, but not too outragiously expensive.
Michael A. Terrell
2007-08-23 13:33:32 UTC
Permalink
Post by g***@gmail.com
Post by g***@gmail.com
Any clue where to locate the schematics for a 1964 Magnavox Astro-
Sonic solid state (ugh!) console stereo? Model number is 2ST631,
Chassis R20507-00. Does a schematic exist? I've looked in all the
usual places I know of online...
Gerry
I take it from the lack of replies that there are no schematics
available anywhere? I couldn't even find this beast on Sams
Photofacts....
Look for the chassis number in the Sams index.
--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
g***@gmail.com
2007-08-23 17:12:26 UTC
Permalink
Post by Michael A. Terrell
Look for the chassis number in the Sams index.
I did. Tried several variations on the chassis number. It's not
there. :-( Just using the main chassis number alone, 20507, only
brought up one Emerson and several RCAs - 17 listings in all, but none
were Magnavox.
Scott W. Harvey
2007-08-24 04:35:07 UTC
Permalink
Post by g***@gmail.com
Post by Michael A. Terrell
Look for the chassis number in the Sams index.
I did. Tried several variations on the chassis number. It's not
there. :-( Just using the main chassis number alone, 20507, only
brought up one Emerson and several RCAs - 17 listings in all, but none
were Magnavox.
The Universal Schematic Locator finds a few Magnavox chassis numbers if
you enter the first three digits, but none of them are yours. This beast
is apparently one of those rare birds that Sams elected not to dissect
and make a schematic package for.

-Scott
Ken G.
2007-08-25 07:07:50 UTC
Permalink
Why do you need a schematic ? is there parts missing , burned or missing
numbers ?
What does it do when you plug it in and turn it on ?
If its all there and nothing is missing or burned it probably needs some
capacitors and cleaning .
g***@gmail.com
2007-08-25 12:56:54 UTC
Permalink
Post by Ken G.
Why do you need a schematic ? is there parts missing , burned or missing
numbers ?
What does it do when you plug it in and turn it on ?
If its all there and nothing is missing or burned it probably needs some
capacitors and cleaning .
The tone is rather bland. Not much bass for a Magnavox. There are
some composite components (resistors and caps all in one little
postage stamp-sized element) and I don't know what values are
contained inside. I'm also not 100% certain which sections are
strictly for the amplifier. There are also some components (mounted
on PC boards - ugh!) that I'm not familiar with. If I had the
schematic, I can probably replace them with more conventional parts if
I knew what they were. I can make out the regular paper caps there
and the resistors, but I'd like to know what the other components on
that board are before I start replacing them, so I can do them all at
once. I've already replaced all the piece-to-piece components, except
for the main electrolytic caps in the can. They are an unusually high
value: 1,000 mfd and 500 mfd. Not sure where to find those. They
seem to be fine for now, so I'll just leave them alone.

Just replacing the components I had on hand brought the left channel
back to life, as it didn't play at all when I first bought the console
for $1.29. I'm hoping I can get a little better tone from it before I
give it to a friend of mine.

I previously had purchased one of these consoles that was a few years
newer, but had a mostly plastic and particle board cabinet. Paid
$12.50 for that one and parted it out on eBay, clearing about $70
profit on the amp and turntable. That one had pretty good tone - much
better than this one which is just three years older - and more like I
expected from a Magnavox. Great bass, although the high frequencies
had a bit of fuzzy distortion that seems typical of most solid-state
units from that era.

I have a feeling that the tone problem in the $1.29 console may be
with the output transformers not having a low enough frequency
response. However, it's cheaper to try replacing the resistors and
caps first before replacing the output transformers and hear how it
sounds then. Might even be the non-polarized electrolyitics in the
crossovers, but they're a little harder to find and/or make because
they're odd values like 8 mfd. I don't want to dump a ton of money
into it, since I'm giving it away, but if I can, i'll try and squeeze
some better bass out of it.

Gerry

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