Author Topic: 1962 Magnavox Astrosonic Stereo Theatre  (Read 3439 times)

PanAm

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1962 Magnavox Astrosonic Stereo Theatre
« on: July 26, 2017, 12:07:31 PM »
Hello, 
I recently aquired a Magnavox stereo theater for $90. It seems to be in immaculate condition and it was originally owned by a couple with no children. When they died, all their furniture was sold with their house. I got the stereo from the people who bought the house. It had been sitting in their garage for 5 years and was unused for a while when it was still in the living room. Everything works like it should except the right side speakers. On radio and stereo phono I get nothing out of them. Same when it is on TV. Already tried tinkering with the balance and was able to get the left side louder but still not sound out of the right. I do not want to rip this thing apart trying to figure out the problem and I am not good with electronics let alone vintage stereo consoles. Now if it was a tube that needs replaced I am capable of doing that. I also wanted to know some background info on this console. I have googled and I can't find another like it. The only reason I know it is from 1962 is because it was in the 1962 Magnavox Catalog in the downloads center. It is the Scandinavia one. It seems to be quite rare. Any info about the stereo or the speaker issue is greatly appreciated. I will include some pictures if someone could help me figure out how to post them. Thank you!

amglow

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #1 on: July 26, 2017, 12:12:30 PM »
Pictures, please. We like to see lots of pictures! :)
Paul

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #2 on: July 26, 2017, 12:27:33 PM »
I'm unsure of how to post pictures. Can you help me? I just joined.

electra225

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #3 on: July 26, 2017, 06:25:09 PM »
Congratulations on your Stereo Theater.  I have been looking for one for two years now.

I would respectfully suggest that if your instrument says "Astro-Sonic" on it anywhere, it is neither an all-tube model nor a 1962 model.  Astro-Sonic is Magnavox nomenclature for their new line of solid state instruments introduced in mid-1963.  They were sold along side certain left-over tube models, many times in the same or similar cabinets.  A genuine 1962 Stereo Theater would have an all-tube stereo with a 23", 24", or 27" all-tube black and white TV chassis.  An Astro-Sonic model would have a solid state stereo with a tube TV.  Color TV was available in a Stereo Theater for the first time in 1963. 

If you have an Astro-Sonic model, and you are experiencing a problem with a channel, I would suggest you clean the controls, particularly the function switch and external speaker switches.  It is possible you need to replace certain electrolytic capacitors in the amplifier to restore function to the dead channel.  Good luck with your Stereo Theater.
I'm great at multi-tasking.  I can listen, ignore, and forget all at the same time.

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #4 on: July 26, 2017, 07:04:55 PM »
Congratulations on your Stereo Theater.  I have been looking for one for two years now.

I would respectfully suggest that if your instrument says "Astro-Sonic" on it anywhere, it is neither an all-tube model nor a 1962 model.  Astro-Sonic is Magnavox nomenclature for their new line of solid state instruments introduced in mid-1963.  They were sold along side certain left-over tube models, many times in the same or similar cabinets.  A genuine 1962 Stereo Theater would have an all-tube stereo with a 23", 24", or 27" all-tube black and white TV chassis.  An Astro-Sonic model would have a solid state stereo with a tube TV.  Color TV was available in a Stereo Theater for the first time in 1963. 

If you have an Astro-Sonic model, and you are experiencing a problem with a channel, I would suggest you clean the controls, particularly the function switch and external speaker switches.  It is possible you need to replace certain electrolytic capacitors in the amplifier to restore function to the dead channel.  Good luck with your Stereo Theater.

You are correct. I forgot that Astro-Sonic was used starting with solid state in 63. It is all tibe with a black and white television. I haven't pulled the back off yet to see what the problem is with the balance. The balance screw in the bottom of the bass knob only seems to make the left speaker louder, and does not bring in the right side. Would it need a new tube? Keep in mind this is my first stereo and am very unfamiliar with the electronics.

TC Chris

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #5 on: July 26, 2017, 07:39:01 PM »
We all hope for the quick fix of a new tube.  However, tubes are actually fairly durable, and it's often something else.  You have already seen the suggestion of cleaning controls, especially speakers.  That's a first step. Caig makes their DeOxit line of cleaners that are generally admired for being effective.   http://caig.com/

Sometimes you can get an oxidized switch to work--a little, and intermittently--by just working it back and forth.  And the same thing goes for tubes.  Their pins can make bad contact wit the socket.  Try wiggling them in the sockets.  Don't get ham-handed and break anything.  Just wiggle some.  Or better still, use some DeOxit on the tube pins and sockets.

If you don't have access to a tube tester, you can sometimes test by moving the right-channel tubes to the left channel and vice-versa.  If the problem follows the tubes, it's a tube.  If not, it's something else.  It's in the amplifier that you'll find discrete right and left tubes.  And the amplifier is probably most likely the place to make no noise from one channel.

Chris Campbell

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #6 on: July 26, 2017, 08:03:54 PM »
We all hope for the quick fix of a new tube.  However, tubes are actually fairly durable, and it's often something else.  You have already seen the suggestion of cleaning controls, especially speakers.  That's a first step. Caig makes their DeOxit line of cleaners that are generally admired for being effective.   http://caig.com/

Sometimes you can get an oxidized switch to work--a little, and intermittently--by just working it back and forth.  And the same thing goes for tubes.  Their pins can make bad contact wit the socket.  Try wiggling them in the sockets.  Don't get ham-handed and break anything.  Just wiggle some.  Or better still, use some DeOxit on the tube pins and sockets.

If you don't have access to a tube tester, you can sometimes test by moving the right-channel tubes to the left channel and vice-versa.  If the problem follows the tubes, it's a tube.  If not, it's something else.  It's in the amplifier that you'll find discrete right and left tubes.  And the amplifier is probably most likely the place to make no noise from one channel.

Chris Campbell

Thanks Chris for your help. I will pull the back off soon to see if there is anything visibly wrong like disconnected wires or such. In the meantime, if I were to go about the DeOxit, how would I get it into the places it is needed in? I don't want to have to rip it apart. I also need to know how much to use.

TC Chris

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #7 on: July 26, 2017, 08:24:45 PM »
You can get it in aerosol spray cans or, as I prefer, a pump-action can.  For switches, I like to use a small artist's brush.  Pump some DeOxit into a small container and use the brush to apply it to the contacts on a wafer switch.  For enclosed switches, you may have to squirt some in via whatever opening is available.  You do have to remove the chassis from the console to do most of this, although some devices have speaker selector switches mounted externally, I think.  For tubes, if wiggling produces some effect, you could try applying some DeOxit to the tube pins alone, or maybe to the socket also via a small toothpick.  That wouldn't require removing a chassis either.

Chris Campbell

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #8 on: July 26, 2017, 09:28:09 PM »
You can get it in aerosol spray cans or, as I prefer, a pump-action can.  For switches, I like to use a small artist's brush.  Pump some DeOxit into a small container and use the brush to apply it to the contacts on a wafer switch.  For enclosed switches, you may have to squirt some in via whatever opening is available.  You do have to remove the chassis from the console to do most of this, although some devices have speaker selector switches mounted externally, I think.  For tubes, if wiggling produces some effect, you could try applying some DeOxit to the tube pins alone, or maybe to the socket also via a small toothpick.  That wouldn't require removing a chassis either.

Chris Campbell

What switches are you referring to? The speaker selectors on the radio panel and the balance screw? Or are there internal switches you may be referring to?

TC Chris

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #9 on: July 26, 2017, 09:34:06 PM »
I'm not familiar with your specific unit.  Exploration is part of the fun of these things.  A dirty speaker switch, wherever it is located, can create your problem.  I have an old but nice Sherwood receiver.  The contacts in the headphone jack get crummy and one channel's speaker cuts out.  Each time it does,  I think it's an amp problem and replace the receiver with another.  Slow learner, I guess.  We always assume the worst instead of seeking the simplest solution first.

Chris Campbell

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #10 on: July 27, 2017, 05:50:54 AM »
Ok. Thank you for your help. I will soon spray the DeOxit in some of the switches and rotate the tubes.

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #11 on: July 27, 2017, 05:52:23 AM »
Pictures, please. We like to see lots of pictures! :)

I have posted the pictures in the Members Gallery section of the Phot Gallery. They are listed under 1962 Stereo Theater. Let me know if there is any trouble viewing them.

electra225

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #12 on: July 27, 2017, 07:02:11 AM »
Model 1MV357, maybe?  Magnavox lead dress in their cabinets is notoriously sloppy.  You might check to see if one of the neutral wires (black) has come off a speaker or speakers on the affected channel.  That would be easy to happen, especially during a move.  The external speaker switch for your Stereo Theater is located above the TV tuner. 
I'm great at multi-tasking.  I can listen, ignore, and forget all at the same time.

PanAm

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #13 on: July 27, 2017, 09:03:21 AM »
Electra225, you are correct about the model number. When I take off the back I will look for your suggestion. I plan to hook up extension speakers to the unit and see if the right extension speaker doesn't work. Then I know something must be wrong with the right side of the unit and the balance is off. I will post about my findings and see if you guys have any suggestions. When I pull of the back I'll take some photos of the inside and add them to the gallery and see if your trained eyes can see something wrong that I can't. In the meantime, I will continue enjoy my Maggie.

electra225

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Re: 1962 Magnavox Astrosonic Stereo Theatre
« Reply #14 on: July 27, 2017, 09:38:07 AM »
If there is a wire off the speakers, the external speakers may not work.  It depends on model series and how the set is wired.  The neutrals are typically connected together.  I have only experienced one instrument with a weak channel.  The problem turned out to be a 6EU7 in the tuner, used as an audio amplifier.  If your instrument has any 6EU7's at all they are immediate suspects.  If a neutral wire was disconnected, a channel or speakers on a channel would be totally dead.  You might want to take a close look at audio tubes in the tuner.  Subbing works well, if you have spares.  Good luck.
I'm great at multi-tasking.  I can listen, ignore, and forget all at the same time.