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Old 09-19-2008, 06:46 PM
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Jeffhs Jeffhs is offline
<----Zenith C845
 
Join Date: Feb 2003
Location: Fairport Harbor, Ohio (near Lake Erie)
Posts: 4,035
The hot-chassis issue is not restricted to Magnavox as any series-string radio, TV or phono amplifier will have a hot chassis, depending on which way the plug is inserted in the wall socket. I have a Zenith MJ-1035 stereo FM radio with phonograph inputs, supposedly isolated from the line by a capacitor. However, I would not think of connecting anything to those jacks without replacing that isolation cap first, and even then I'd think at least twice before plugging any kind of modern electronic gear such as an iPod into them. As was mentioned, this is (or could very well be) a disaster waiting to happen. I wouldn't plug anything other than a stereo turntable into those jacks, even after replacing the isolation cap. The risk of shock and/or equipment damage, in that order, is too great.

BTW, the preamplifier stage in my MJ1035 is in fact a 12AX7, the output stages are 50EH5s, and the radio sounds absolutely great, except for some background hum (probably a loose or missing ground connection). Zenith obviously did not skimp on much of anything, IMHO, when they designed this set, the speaker issues (which have been discussed at length in this forum) notwithstanding. I personally cannot tell the difference in sound between the MJ1035 and my C845 (the latter has the same speaker system as the MJ), except that the MJ sounds more mellow than the C845 because of the MJ's larger cabinet. I have found, after doing some research on the MJ1035, that the radio uses the same chassis (11J01) as Zenith's console stereos of 1965 vintage. I'm not surprised. This chassis has "high fidelity" written all over it, not to mention a front end hotter than a firecracker (I was listening to CBC Radio One from London, Ontario, Canada on my MJ1035 this afternoon, and I can get stations from Windsor and other SW Ontario cities, not to mention Detroit, Toledo, Ohio and Erie, Pennsylvania on this radio as well from my apartment in northeastern Ohio, using just a six-foot length of wire as an antenna).

The only thing I wish Zenith had included on the MJ1035 is external stereo speaker jacks. If this set sounds as good as it does through its own speakers, I would think it would sound as good as any hi-fi system if it were driving high-efficiency speakers. The only problem I can see with using any other speakers with an MJ would be that the impedances are non-standard; the main speaker is 4 ohms and the HF driver is 46 ohms. While replacing the main driver with an 8-ohm speaker won't harm the output stages (it will only reduce the output volume a bit), the tweeters are a different story. Putting any type of speaker of less than 46-ohm impedance in this position in an MJ1035 (or any type of audio equipment, for that matter) is asking for trouble, as the use of a speaker of lower impedance than the original will damage the output transformer and possibly other parts of the output stages as well.
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Jeff, WB8NHV

Collecting, restoring and enjoying vintage Zenith radios since 2002

Zenith. Gone, but not forgotten.
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