Classic Hifi Care

I had a very odd experience with an Astrosonic Magnavox player W600 series, not a mechanical issue but one of cartridge wiring. Using one of my "spare" changers in a 1ST688 I just serviced, mono record sounded great but a stereo record literally played as if the vocal was missing! A second and third stereo LP sounded "off"

In this case, I have two Magnavox Micromatic changers both with original P156 (EV150 series) carts that are presumed OK. As I service the one, I used the other to test the amp performance and was quite surprised by what I heard.

The tonearm wiring on these consists of two thin shielded cables, braided outer conductor is grounded. The polarity seems foolproof from RCA jacks to cartridge, but I suspect the two inner terminals on this cartridge are NOT both negative. The two were joined by a wire assuming both are negative. This would explain the cancellation of material common to both channels on a stereo record.

Both Pfanstiehl P226 (Varco TN4) and P192 (BSR SC8) are a larger size but can be made to fit the black tonearm with single screw mount. The Tetrad (EV5632) series carts are smaller but require a plug which has polarity marked. Normally, this is my go-to repair for these changers.

I used the Tetrad EV 5632 in my Imperial. I like how it sounds. I can understand how wires to the cartridge could get crossed and confused.

electra225 wrote: ↑Mon Jul 29, 2024 11:37 pm I used the Tetrad EV 5632 in my Imperial. I like how it sounds. I can understand how wires to the cartridge could get crossed and confused.

I have three (!!!) of the Micromatics with the original EV132-150 cartridge and YES indeed, the 5632D will work well. The two I have for sale right now have a BSR and Tetrad replacement installed. The compliances widgets in the original EV cartridges are shriveling to nothing, so eventually a repair should present itself - many styli are available for them.

A bit of fine art soldering needed here, photo via my magnifier/circle-light

That is exactly the same cartridge as I put in the Imperial. Mine is glued in place.