'56 Magnavox
 

I just bought this '56 Magnavox record player at the flea market. One unusual thing that I see is that it uses a VM changer. I've only seen one other VM changer in a Magnavox and it was in a lower end portable from the late '50's. I thought the medium and higher end stuff used Collaro and Webster-Chicago changers.

The amp uses a power transformer and uses the following tubes: 12AX7, 5Y3, and 6AQ5 x 2. There are controls for bass, volume, and treble. Upon power up, I find that the changer is gummed up (no surprise) and the amp is totally dead (no tube filaments). Overall, the case is in decent shape and should only need cleaning and polishing.

http://i538.photobucket.com/albums/f...GNAVOX0003.jpg

http://i538.photobucket.com/albums/f...GNAVOX0002.jpg

http://i538.photobucket.com/albums/f...GNAVOX0001.jpg

Well, I have bad news. The reason it's dead is because the power transformer is burnt to a crisp. Hopefully, I can find something in my junk that will work. I certainly don't want to shell out for a new transformer, if I can help it.

How about repairing the transformer?

I think it's past repairing. When I opened it up, it looks like it actually caught on fire. And, the chassis is black in the area surrounding the transformer. I think someone let this one smoke and burn until the primary winding opened up.

It's perhaps possible to gut the transformer and use the core to rewind a new one. Less work, of course, to find a substitute. Especially in this case, where there is really nothing special about the unit and nearly anything close will work.

It points out the cheapness with which these things were made. Cost was the important factor. Times haven't changed at all.

These things cost $129.50 in 1956 and were not cheaply made at all. I just finished recapping an amp from one and the amp and the dual 6x9 oval bass drivers and five inch mid range sound fantastic. 1956 tubes work as good as new.

Filter caps dry out and short and if you plug the amp in the transformer will catch on fire. Now, as to why they didn't put in a fuse, you got me.

sounds like someone let it run with a shorted lytic and bye bye transformer.

I'm amazed Magnavox didn't put a fuse in the power supply, to protect the transformer against shorted electrolytics or even a short in the rectifier tube. However, I have to wonder why the house fuse or circuit breaker didn't trip open as soon as the filter cap shorted; after all, these caps are in a position to short the AC line directly to ground when they fail. Another thing: Didn't the set's owner notice that the sound had a 60-Hz hum when the filter cap started to go bad, long before it shorted?

As much as these Magnavox phonographs cost when they were new, I don't think it would have added that much to the price to include a line fuse. Magnavox was a top-of-the-line manufacturer in the 1950s, not one to cut corners, which makes it difficult for me to understand why they would leave the transformer unprotected. The only other thing I can come up with is that there may well have been a line fuse in the set, but the owner foolishly bypassed it. Again, I wonder why the owner didn't get the hint when the sound became distorted from 60-Hz AC hum when the filter cap was just starting to fail. Why the person would just leave the thing on when the cap eventually shorted, leading of course to the transformer burning up, is far beyond me. :scratch2:

I really wished more manufacturers would have put a fuse in the power supply but almost none did (but I always do when repairing). The only Magnavox tube type radio or phono I have ever seen with a factory fuse is a 1946 large radio/phono console I have.


I bet you can replace that transformer pretty easily, you might have to go to a silicon bridge rectifier or silicon diodes or a 6X5 tube if you can't find one with a rectifier filament winding. Just as long as you don't go over the voltage of the original supply I would think a somewhat lower voltage output unit would do too. You could use a bridge rectifier off the center tap and outer lead of a higher-voltage output unit.

i can tell you that the VM turntable that is on your unit is NOT the original, the original was a brittish made Collaro. the reason i know this is because i have the exact same identical model here. mine, however is fully functional & in working condition. it even has a really good quality sound to it.
if you can find the original turntable for it at a low cost or free, then it would make it worth restoring. otherwise, being that the transformer was burnt to a crisp, & the original turntable missing, as well as the modifications that was done to the deck that holds the turntable in order to make that VM fit, it just leads up to being a piece of junk.

not necessaraly, i personally witnessed one of these failing on their own accord due to a winding that has a shorted turn. that usually happens with no warning & ends up burning up pretty quickly.

I thought the same thing, until someone on ARF chimed in, with the same machine, that uses the exact same VM changer. And, I did find out that Magnavox used some VM changers during the '50's. If this changer is indeed non-original, someone did a good job as most of the conversions I've seen were very sloppy. Of course, I'd rather have the Collaro version; but, at least someone didn't stick some plastic '70's BSR changer in there (I've seen that done more than a few times).

Magnavox used V-M changers in some models at least through the early 1970's.

Here's the specs on that power transformer:
Primary: 117vac @ .37a
Sec. 1: 475vct @ .064a
Sec. 2: 6.3vac @ 1.8a
Magnavox 300068-1, Halldorson P9205, Merit P-3048, Stancor PM-8419, Triad R-8B

I have the Sams if you need me to scan it.

Actually, I did find a transformer. I just have not had time to finish installing it. Thanks for the diagram offer; but, I have the schematic on this amp.

I have the exact unit that radiotvnut has and the vm changer is original. There are no modifications to the deck and it fits perfectly. :nono:

FYI,

The use of a V-M changer in a Magnavox was unusual. But as pointed out, some units were originally fitted with one. With stereo compacts, there wasn't a suitable Collaro mini changer model to fit in them, so usually they had Philips changers or had BSR factory fitted in them. I think with this one, there might have been a delay getting Collaros or similar reasoning.

There was one real POS full size Magnavox changer from the early '70's. I don't know who made it; but, they should have forgot about it. This changer was all plastic, had a very short record spindle, and had silver function selector buttons. I've never seen one of those that worked right and they'd make a '70's plastic BSR look high end. I once knew a Magnavox service technician and he told me that he called Magnavox to let them know how ashamed they should be over using such a junky record changer. Their reason was that they had to keep up with their competition.

Magnavox Mini changer from VM, Magnavox Automatics
 

Magnavox did not use VM changers because Collaro wasn't available, it was more for use in their less costly sets. Around 1966-67, they made their own budget changer for the cheapest mono portable to the tiny consoles and budget component sets. When they came out with the really small three piece stereo radio, they used a VM mini changer as an option for record playing, and later put that mini in some sets that were sold all together. The wretched pushbutton plastic atrocity with the tuning fork overarm seems to have been introduced on component sets, drum tables, and some of the cheaper armoire configurations. I believe they worked as fast as they could to retrofit customer sets with these failures, using the Magnavox Automatic, and then the next model year had the Automatics in place of these "Mark I" plasticrap bomb. Magnavox techs and experts, please correct me if I'm wrong, or add your take on this line of reasoning.

In my humble opinion, Magnavox never made anything really good. Yes, they were driven by competition, just as everyone else in the business was. Many tried to uphold a shred of dignity but by and large, it's a money driven society.

Now and then a small outfit would spring up that made really nice stuff but nearly all of them went belly up or lowered their standards.

Virtually all the big companies sold out to Asian or European outfits. It's not limited to electronics of course; I have a Mexican saxophone with an American brand name, for instance. RCA is European. Fisher is Japanese. The list goes on.

I had a similar model with a VM changer. The only difference was the knobs were on the front instead of on the top. The front of the unit pulled forward like a drawer to reveal the amp. Really a neat little machine. I sold it about a year ago..

The VM changers being used in less costly sets using full size changers is sensible and I think correct. Talked to a ex retiree Magnavox dealer, he told me the economy mono consolettes were fitted with a VM 1200 family changer, the Collaros were used in the model up from the economy model. The 1966 and later economy changers were spot on as far as magnasonic66 is concerned. The Mark 1 plasticrap bomb changer was a very badly made and engineered unreliable nightmare (Maestro built these failures under license or bought the tooling, this and the last RCA changer design tied for the worst USA built changers of the era). The Automatic 400 was a very decent changer for a economy changer.

Interesting....I never saw a Magnavox of that vintage with anything other than a Collaro changer. I wonder if the ones with the VM changer sold for a lower price, as the VM's certainly cost less.

As long as we are doing a bump, I MUST comment that Magnavox tried to make something for everyone's budget and did some things extremely well from the very beginning such as speakers and cabinets. A record machine with a low-power tube or SS amp in a cheap cabinet was in the back of their brochures for years. Yet even a mini-console still had a decent Collaro or Micromatic changer. You have to give them props for that!

But of course, Mag's flagship pieces like the Concert Grand, Imperial and Astrosonic 100 made the front pages of their 1947 thru 1971 catalogs and sales brochures.
Magnavox outlasted many manufacturers of record machines that built world-class consoles like Fisher, Motorola, Admiral, Sylvania and others who chose to exit by the 1970s.

If the declining quality of their offerings made Magnavox a mediocre brand, it only became SO later such as the decline of Zenith and RCA in the middle 70s when consoles became obsolete and cassette tapes bested records before CD's turned it all upside down:sigh:.

These same manufacturers migrated from better quality V-M, RCA and Collaro changers to BSR changers and another one I forget, which like them or not, was the token changer offered in component combos and consoles then. I also had to fix those too.