Otari 4-track Working!

analogkid

I Bleed Analog!
I did it! I found the damned trouble with Channel 4 on my MX-5050 QHXD. If you missed the earlier story, I was lucky enough to get some free analog decks a while back, including this Otari 1/4" 4-track. The only bust was when I got it home, channel 4 would record but was distorted and cut in and out. After cleaning and demagnetizing it still didn't clear up, and I began attempting to trace the problem. The heads appear to be in quite good shape - no gaps or abnormal wear, so I began looking in the preamp. This unit has the preamps and all the level and bias adjustments in an outboard unit. Pardon my lousy photography skills here:






You can see in that first picture, if you look closely, that on teh far left is the playback head, and you can clearly see that each wire is soldered to the contact on the head. Looking to the right at the record head you will notice that instead of being soldered, each wire actually clips on! Turns out (and no suprise really) that the wires connecting channel 4 on the record head were making intermittent contact due to oxidation - likely the other heads were soldered on as a mod by the original owner, as I suspect the clip on wiring was how they came from Otari.

The next two blurry pictures are of the transport section and the preamp section - you can see all the calibrations available on the front of the preamp.

My plan at this point is to go back and solder each of the wires to the head so this issue doesn't crop up again. Now, off to calibrate this bad boy!

AK
 

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