Magnavox stereo repair

[jfalberti]

Good morning/afternoon all.  I have an early 70's  Magnavox Astro Sonic console stereo that needs the amp/tuner repaired.  The changer works great, and it plays, but the left channel is weak, and I think it is about time to just have it completely re-capped.  Does anyone repair vintage electronics like this or know of someone that does?  I'd be more than happy to remove it from the cabinet and ship it to someone to fix it, and pay them to repair it.  Any suggestions and advice is greatly appreciated.   I've attached a photo of the amplifier/tuner in my stereo so you can gauge how old it is.


 


Joe

 

[jfalberti]

Also

Here is a picture of the record changer.  This is when I first got it and it is pretty dirty in the picture, but it has since been cleaned up and it works flawlessly.  I also stock piled several new stylus for it.

 

[vacosaurus]

You might inquire even though this unit is probably solid state on antique radio forum or antique tube forum for someone in your area for repairs or advice. You might try getting some electronic tuner/ control cleaner in the spray can and with the small plastic tube that comes with the tuner cleaner spray some in the Left - Right balance control and then work control back and forth. You would have to do this from the inside of the unit there is usually a terminal or some kind of small hole on the control to shoot the cleaner inside of control. Don't be afraid to shoot cleaner into control it evaporates very quickly. Flood it if you can and then work it back and forth then let it dry for about a half hour before trying it. It might correct your problem with the balance. Also if your volume control is erratic or scratchy when you change volume it might need a shot of tuner cleaner/ lubricant too. I would try this first as capacitors from this era last a really long time and it is usually dirty controls causing problems. These old stereos sounded great but have little collector value if any. But if you personally like and it brings you enjoyment go for repairing it. You can buy tuner cleaner/lubricant at Radio Shack. Bill,

 

[arh1953]

Joe, your set looks suspiciously like one of the armoire styled models, it came with and without the color TV. You can try switching the speaker switch around, that's what I had to do with my 1966 console that seemed dead on the sales floor. You will want to leave it on the INT setting if that is the case or not, at any rate. Also, I'll recommend you join the Yahoo group Magnavoxfriends, if you want anymore feedback. And Vacosaurus has some great information.

 

[jfalberti]

Thanks guys

and right you are Alan,  It is <a name="start_24179.270560">one of the armoire styled models.  It didn't have the TV.  A found a Magnavox reel to reel deck, and that is installed in it.  It is solid state, and I'll try both of you guys suggestions.  Thanks again.</a>


 


Joe

 

[arh1953]

You're welcome!

I bought a Magnavox (Panasonic) reel to reel deck for my armoire, but I can't put it in the set because I don't have any holes for the patch cords, and I'm not drilling any. I might just hook it to one of the Magnavox component sets I have instead. And, here's hoping yours is an easy fix!

 

[Anachronism]

Electronic nostalgia

I used to design, build & repair sound systems in the '60s, then in '69 I got drafted into McNamara's Band. At the end of my enlistment everything had become transistorized & my days in electronics were over, however, I do remember spending a lot of time with reel to reel recorders by Magnacord, Ampex & Wollensak, and my parents had one of those Magnavox units with a tube-color T.V. - NOT my favorite unit to service!

 

[arh1953]

Magnavox television wasn't a particularly reliable product, unfortunately. Their strong suit were console radio phonographs, and then stereo consoles. And then they had components and modulars for people who didn't like the big space suckers. I'll bet your electronics career was fascinating!

 

[Anachronism]

One of the best radio audio sections I encountered was the Magnavox 6v6 push-pull used in late '40s sets-- I copied that circuit many times

 

[tolivac]

I used to deal with Ampex,Scully,Studer,Magnecord RR machines-they USED to be workhorses in the broadcast industry-any radio station large or small had several RR recorders.Loved the tubed machines-not only easier and faster to repair-but sound quality was better-esp over the early SS circuit designs.PP 6V6 amps-annother workhorse.I have found 6V6 tubes in lots of things-even used as oscillator tubes in Gates AM transmitters.A Signal Corps Army surplus record player-PA system I have has a PP 6V6 amp-if you watch Hogans Heros-this player "stars" in the show-the funny announcements the show charactors made on it.Necomb,Califone "school" record players-older ones had the 6V6 amps.Magnavox Concert Grand models had power amps in them that are Bi-amped-4 6V6 in PP parallel for the LF speaker,and a pair for the tweeter.Nice amps!!!!In their days 6V6 is a workhorse-smaller cousin to the 6L6-and VERY popular today-not just Hi-Fi gear-both of those tubes made for "G" fiddle amps!

 

[Anachronism]

I built many a "G" box amp around 6L6s, and a few using 807 & 1625. My favorite source of preamp parts was the Silverstein Surplus store in Detroit, not only much Korean & WWII com equipment, but plug-in panels from Borroughs computers that could be used as pre made chassis and loaded with high tolerance parts. Can't repurpose modern computers that way! Of course, my house couldn't hold one of those, and my service drop couldn't handle the heater draw-----------

 

[paulg]

I have the same unit

And it had a similar problem. Before ripping it apart, check for an internal/external speaker switch on the rear of the unit. Flip it back and forth a few times. Mine oxidized and one channel would go weak.

 

[tolivac]

I used to make various amps from surplus parts-now the "tube" surplus parts have dried up or become outlandishly expensive as in the "hi end" Hi-fi.So remember a surplus store a couple decades ago that had boxes of JAN 300 tubes for like a buck each-can you imagine what you could make from those today-some Hi end Hi-Fi folks pay $300 for a 300 tube!And to think originally the WE300 was used in amplifiers in their telephone networks.The tube days were fun!And so easy to breadboard-new stuff is difficult or IMPOSSIBLE to breadboard.
Oh yes,for Magnavox and some other console Hi-Fis-the forgotten int-ext speaker switches cause a lot of greif when they are just that forgotten and not moved now and then to wipe contacts clean.