Strange Molex

[eacolaianni]

I acquired a 1962 Magnavox console that had been in a barn for a while. I was able to get it working, but the FM stereo decoder has a broken Molex connector. The pins are the same kind that the connector that is on the 9300 power supply/power output uses to connect to the tuner/pre-amp chassis. I haven't been able to find that style of Molex connector anywhere. Do any of you know of a source for these, or were they Magnavox proprietary?

[electra225]

As far as I know, it was a proprietary Magnavox part. I don't know of a source you can buy them currently. About your only option is to find one from a parts unit.

Welcome to the forum! We hope you will enjoy the forum and will join us often......

Edit. I dug thru my junk box and found the ends of a couple of MPX to amp/tuner cables. If you would be good enough to post a picture of what you need, I'll be happy to check to see if something I have will help you.

[Hydrolastic]

Hello guys, I had run into this before. I had a MPX unit I went to put onto a AMP 175 and the plug was slightly different it was perplexing since it fit in another AMP 175 that was just one year newer. Then on my CG I went to remove the MPX since I never use the radio I didn't think it needed to be on every time I wanted to listen to the stereo (on Blue tooth) I quickly realized that the in plug on the MPX unit has a slightly different plug from the amp side so it was kind of acting as an adapter. One thing I want to do on the CG is make all the molex plugs the same. If you want I can take photo's.? They look very close to the same plug.

[William]

Hydro, please share a photo I am sure it will help everyone to see any differences on these plugs.

Welcome to the forum, eacolaianni, and thank you for sharing your Magnavox project with us.

Bill

[TC Chris]

I haven't checked Mouser or the other wholesalers, but I am wondering what other kinds of multi-conductor connectors are available. There used to be "Miller plugs" in various configurations. The Molex devices seem to be cheap, fragile, and unreliable. Replacing them with better devices would seem to make sense unless the electronic device is of museum quality.

Chris Campbell

[Hydrolastic]

Hello guys, So here is a photo of the plugs for the MPX on the CG. The round pin one is the output of the mpx the flat pin is the input to the mpx from the preamp. I can't find the mpx unit that had the different pin connector right now. Idk it could just be a replacement.

[electra225]

All the Molex connectors I am familiar with have flat pins like in the top connector. Perhaps the lower one is a replacement. The Multiplex adapter on my CG is mounted across the opening for the tuner, right above the tuner power supply chassis. I think factory placement is on the back. What a pain that would be to remove the back with the MPX hanging off it, along with the bazillion other speaker and antenna connections.

[eacolaianni]

The Molex connectors on almost all of my Magnavox equipment looks like the one in the top photo from Hydrolastic. I'm also betting that it was proprietary to their tube-type equipment.

[electra225]

I have a 2ST253 from 1963 that uses the round pins like the lower picture. It also has a differently oriented Molex connector that won't let you use MPX adapters from earlier models. You have to use a proprietary stereo decoder, They even put a plug on the back of the apron of the chassis to plug one in.

What kind of Magnavox instruments do you have? I have six, including a Concert Grand, Imperial, Stereo Theater, Symphony, Contemporary and the little 1963 model that really doesn't have a name. I have the most expensive models to the cheapest with P-P amplifiers.

[eacolaianni]

I'm just starting out my new hobby with the 1962 console.

[electra225]

1962 was an interesting year for Magnavox. So was 1963. 1961 did away with eye tubes and introduced the S-600 Collaro changer. The 93-series amp came out in the 1961 models. The 1962 model Magnavox instruments are hard to document. The only 1962 Magnavox I have is a Stereo Theater. You can read about it on the Console Tales board. You might post a picture of yours and tell us more about it. I found a MPX to tuner harness that I used for parts. It still have both Molex plugs on it if that would help you.

[eacolaianni]

Hello Electra: I have a 1962 2ST661 with a 57-10-10 tuner/preamplifier and a 9302 power supply and audio output chassis. I have learned that the Molex connector on models like mine was proprietary to Magnavox. The only capacitors that were bad were to two in the crossover network, for some reason. I updated it with new ones with about the same characteristics. I installed a Bluetooth receiver and my next project is to get the R-600 working. Right now, the unit is sounding great with the BT, but my outside FM antenna overloads the front end of the 62 year-old. I'll use the one that is stapled to the rear cover.

[electra225]

I'd recommend that you also change the capacitors and check the resistors in the amp chassis at least, preferably the amp chassis and the tuner. You have what is referred to as the "little" Imperial. Basically a souped-up Symphony series. That is the one model left on my bucket list. The capacitors in Magnavox amplifiers are really not very good. The 220K ohm grid resistors tend to drift really high. You need to check the bias components in the output tubes, then check the bias on them. This all should be done to preserve its life, and also make it sound its best. The original output tubes are made in Japan and are not that good. You can get reproduction, modern 6BQ5's that will handle more plate voltage than the originals and you can even buy a matched quad for maximum performance. You own one of the better series of Magnavox stereos ever built. I hope you enjoy it for many more years.

[William]

And don't forget to install a fuse.

Bill

[electra225]

Good catch, Bill.....

[Hydrolastic]

Hello guys, so when I took the photo of the strange molex plug, on reassembly I could not get the CG to turn on. I took it as a sign to replace it so today I put my alternate power supply in and removed the MPX. The preamp then plugged directly into the power supply. Using the correct terminals. The CG is running again! So next question "whats the fuse I need to install ?"

[William]

Hydro. The installation of a fuse, because it is rare that console manufacturers used them, is to protect the power transformer in case the electrolytic filter capacitors failed. EFC failure can quickly wipe out a power transformer.

Bill

[electra225]

On your CG, you want to put a fuse in each amplifier, then one in the power supply chassis for the tuner. I used a 1 1/2 amp fuse in each on mine. Mine also has the MPX, which is protected by the fuse in the tuner power supply chassis. I have never had the remote control chassis on in my CG, but if you use it, it needs a fuse as well. You can calculate the value of the fuse "down and dirty" by connecting your Kill-A-Watt in series with the remote control chassis, get the wattage, then calculate what size fuse you need. As a practical matter, the fuse more protects your house than the PT, but that is probably just a matter of how you look at the matter. The best protection is to fuse both the primary and the secondary of the PT, but nobody ever does that. Consoles didn't have fuses from the factory because it would have cost a few pennies more per unit (they had to keep the bean counters happy, you know) and they were not supposed to be being used 60+ years down the road......