Magnavox 2ST653 console stereo evaluation

[electra225]

This is my smallest, cheapest Magnavox console stereo. This was/is the wife's daily driver for eons. The only thing I have ever done to it is to replace the half-dead 6EU7 in the tuner. It has most of the factory dust and cobwebs still intact. It has an unknown/un-remembered model number tuner, but it is one of the 6-tube models, typically referred to as the Series 100 tuner. This little stereo is an extremely late, mostly coded the 31st week of 1963, 1963 model. It is as close to an Astro-Sonic as you can get and still have tubes. It has an 88-03-00 amp chassis, equipped with a uniquely configured Molex connector. The amount of terminals are the same and in the same order as the older models, but the connector itself is smaller and has round terminals instead of rectangular. So it requires what is probably a late-1963 model-only Multiplex adapter. I may have to find a proper Molex connector and terminals, then modify an older MPX adapter to work. The speakers are coded Chicago Telephone Supply, the 31st week of 1963. It has a 12" and two 4" speakers per channel. It is your typically robust performer typical of the little Magnavox instruments. It suffers from horribly dirty tube socket contacts, dirty controls, and wonky FM performance at the top end of the dial. It pulls 59 watts, is rated for 150 watts. Somebody before I got it replaced the original Collaro changer with a foreign-made two speed belt drive changer with a magnetic cartridge. Volume has to be run fairly advanced to get adequate volume. Of course, they hacked the Molex connector for the changer, so I need to find one of those. I have a suitable late Collaro changer to replace the one in there now.

Compared in size to the Stereo Theater

Unique knobs with Astro-Sonic trim and the aftermarket changer.

Magnavox emblem

Amp chassis and dangling wiring. The tuner has connections on top of the chassis rather than on the rear apron.

Magnavox finally put the external speaker and antenna connections in a spot not connected to the rear cover.

It was fixed in 1971. Wonder what the trouble was?

Tubes aglow....

Speakers

The tubes are marked "Japan" allegedly by Siemens. Dated weeks 23 and 25 of 1963. All the tubes in the amp appear to be factory.

[William]

It has the same speakers as my Columbia/Magnavox, but mine is single ended 6BQ5's. I do not have the tuner; my controls are on the front of the unit. One of these days I should look up what the Magnavox model number is. I just looked it up. It was called the Aristocrat, model 1-SC268F and sold for $199.50 in 1959.

Bill

[electra225]

I think this one was a touch under $300 new. It has the coolest-running power transformer of any of my Magnavox stereos. I ran it for about three hours at 125 volts on the line and it was barely warm. I think I'll add a fuse and do a tune-up on it. Whomever replaced the original changer, also tossed the shelf between the amp and the changer. It's only Masonite, so I should be able to make another one. I need to remove the changer that's there now and find out if they hacked the plinth. If not, the swap should be straightforward. The amp has a 6CA4 rectifier that does not set right on top of the PT, so that may help the transformer run cooler.

[TC Chris]

It's a good looker. Did the prev.owner add a preamp for the replacement cartridge?

I've got the same Philco as I see over the top of your ST. a '41 or '42? Can't recall.

Chris Campbell

[electra225]

No pre-amp. It works, just not very loud. That's why I want to put a correct changer back in.

[Hi-Fi-Mogul]

I also really like the cabinet styling.

[walyfd]

That's a clean style. Also like the lighter pecan color.

[Firedome]

looks like the audio version of the "aircraft carrier" behind it, nice style.

[TC Chris]

No pre-amp. It works, just not very loud. That's why I want to put a correct changer back in.

Or maybe add a little one-transistor preamp? I recall seeing a schematic somewhere for that and have been meaning to track one down for the older devices that have defunct cartridges, or for running good-quality audio into the many old radios that have a "phono" or "TV" input.

Chris Campbell

[electra225]

The sticker says the finish is "LT WAL". I reckon that to mean light walnut. I'd say pecan, but whatever.

I may have come up with a possible solution to the weird Molex connector situation. My thinking is I'll never find a Molex connector new. My thought is to buy an MPX, then rob the Molex connectors off it. There are two MPX adapters on ebay right now. One has the connectors cut off already. I can use them both for parts. I will change out the Molex connectors on both ends. I'll have to replace the one in the amp chassis and the one on the end of the wiring harness. I'll wire it like it is now, in case there is a difference. Then I'll have to follow each wire to its termination to make sure the MPX adapter will still work. It will be a tedious job, but I don't see any way around it, if I want stereo FM.

The sharp eyes on this forum have not mentioned that the cabinet on this little stereo is a dead ringer for the 20" longer and 3" higher cabinet on the Stereo Theater.

This little stereo was on its way to the landfill when we rescued it. The wife was the one who noticed it. I had gone to a home in New Franklin, MO to buy some car parts. This stereo was on the curb with junk stacked all over it. I asked if they would sell it. They said it didn't work, but that they would help load it. They even dusted it off so we wouldn't get our rig dirty hauling it. They were as glad to get rid of it and I was to get it. I took it home, plugged it in, turned it on and it worked just fine, still does.

[Firedome]

"The sharp eyes on this forum have not mentioned that the cabinet on this little stereo is a dead ringer for the 20" longer and 3" higher cabinet on the Stereo Theater."

Ummm... look 2 posts above!

"looks like the audio version of the "aircraft carrier" behind it, nice style."

[electra225]

Perhaps it is I who should get some sharp eyes? Sorry Roger. That aircraft carrier is something I put more time in than I typically did restoring a car. It is only 60" long, so it's fairly compact by aircraft carrier standards.

[electra225]

The tuner in this thing has model number 7608-10. I haven't looked yet in Sams to see if they have a schematic for it. I need to know if this is wired like the older models. If it is, I'll change the Molex connectors so I can use a MPX adapter. If it's not, this stereo won't get stereo FM capability. I hadn't planned to get this deep into this stereo at this time, but here I am again, another job out of sequence.

[electra225]

The model 7608-10 tuner in this little stereo is different from any tuner I have worked with dealing with Magnavox. The design and workings are basically the same as the other "Series 100" tuners, but the connections are completely different. I discovered something else even more interesting. There is an outlet on the rear apron of the tuner chassis, a line-voltage outlet. I don't know yet whether it is switched, but I'm guessing it is. If this outlet is switched, that may be the answer for installing a Multiplex adapter with a minimum of fuss. Just obtain an aftermarket Multiplex adapter and use it. I won't have to rewire Molex connectors or any of that. Seeing that outlet causes me to wonder if Magnavox built Multiplex adapters specific to this tuner. They may have intended using aftermarket units rather than having to come up with one specifically for this one-year only tuner chassis. The only other Magnavox tuner chassis I have with a power outlet on it is the Stereo Theater, used to power up the TV chassis.

[electra225]

With the exception of installing a fuse in the amp chassis, I'm done with the electronics. The outlet on the rear apron of the tuner chassis is switched, both from the main power switch on the treble control and the switch on the record changer. I have the replacement changer setting in the cabinet. The original plinth was not hacked, a new one sat on top of the original. I need a Molex connector for the changer power and some suspension springs. I thought I had those, but, alas, I don't. I will try to find a stand-alone Multiplex adapter. Surely somebody has one they aren't using. I also still need to go thru the changer. I don't remember if it works or not. It's pretty nice cosmetically. I believe it has an EV 132 cartridge, but don't quote me on that just yet.

All the guts spread out on the bench.

Adjusting the balance to get both channels set right. I even used identical VTVM's...

Test drive after setting the cathode bias.

Power outlet on rear apron of the tuner chassis to power a Multiplex adapter, switched.

75 watts power consumption, give or take, not including the changer motor.

I believe a 1-amp fuse should be about right.

[William]

It looks good, Greg. You got a lot done today way more than I did.

Bill

[electra225]

I took a two-year hiatus, if you remember. I am so behind I may never get caught up. My problem is working on stuff out of sequence. I'm supposed to be working on my TV Analyst so I can finish the Stereo Theater. I've only had it six years (!), so how much more time do I need to dink around before I get it done? I trip over something, then it gets moved to the front of the line.

Another problem I have is something that I thought I had fixed breaks, then it gets to the front of the line. I didn't have the energy to fix it right the first time, but I have the energy to do it again.

[electra225]

I have everything back in the cabinet with the exception of the amp. I need to get to Tempe to get some fuse holders yet. This week will be table refinishing then car washing/waxing and the community-wide yard sale on Saturday. Next week, maybe, I can get the fuse holder. The parts I need for the changer are on their way. After that is all done, I need to do a baseline on the changer to see what it needs otherwise. I have no idea, or don't remember, what it needs if anything.

[electra225]

Whatever I did to this little stereo sure helped it. The bass is as good as the Symphony in most material. I used the CD player I had on the Concert Grand and played it all afternoon. I'm impressed. I set the bias on the output tubes at no signal. I believe the next stereo I am going to do the balance routine to is the Imperial. I also would like to try using the 1000hz audio note generated by the TV Analyzer rather than the 400 hz tone in the signal generator. I had always just used a mono signal to set the balance in the past. I don't believe that's as accurate as using a generator of some kind. You also want to clean both the hum and balance controls well before making the adjustment so you don't work thru a dead spot in the controls. If that happens, you think you are getting an accurate setting, then it changes. I am also going to make a better RCA jack setup so I can inject a mono signal into both stereo channels.