Otari 5050 8-Track: Noise, Static, HELP!

[sethl]

Hi Folks,

I own an early-model (two "suitcases") Otari 5050 1/2" 8-track. My understanding is that the machine was used regularly as recently as 10 -
15 years ago, but has been pretty much dormant since then. I cleaned and
de-magged, and aligned and calibrated it for +6 (I understand Otari
recommends +4). All in all, the machine set up very easily and needed very
little adjustment. For the most part, everything works just as it should.

However, after tracking a couple of songs, I'm noticing a disturbing static. It's audible on some tracks while monitoring in "source" (some worse than others) and worst of all, it's occasionally making its way to tape.

Seems like there's two issues: The random static during monitoring, and
then a harsh kind of clipping distortion (definitely dependent on the source material) during playback. This would suggest that the repro circuitry is simply being overloaded, and I'm going to re-align the deck to make sure I didn't screw something up. (I'm not an expert, but I've aligned a few decks successfully before.)

I've ruled out my mics, cables, and pres. I've thoroughly sprayed out all
the pots and card slots.

Aside from that, any suggestions? I really can't tell if the caps on the cards are original; some people on other forums have suggested that the popping noises / static may be due to bad transistors on the rec / repro cards, but honestly I wouldn't even know how to test them. (Just checking for voltage on all three legs?)

Anyway, I'm pulling out what's left of my hair and I'm open to any
suggestions or advice!

Thanks,
Seth

[Afunk]

The suit case Otari's are from the early 1980's You can tell from the serial number the first few numbers give the year of production. Basically a machine of that age capacitors need to be replaced and or transistors, not sure if that machines is from the IC era. It would have to be trouble shot by a service tech.

[sethl]

Hey, thanks for the info! As it stands now, all tracks have an intermittent static during tape playback. Also, track 8 has a harsh buzz (and no signal) if I monitor from tape. Swapping cards doesn't change a thing.

I've talked with a tech, but anyone in town who will even look at decks is slammed. So for the time I'll use my primitive troubleshooting tools and see what I come up with.

[aurelialuz]

replace the relays.

[klangtone]

hmmm... I've had similar static issues with my Otari machine. They always seemed to be somewhere in the path of the signal going to tape, but not in the input monitoring section. So I would never hear the intermittent static until playback. But if I put my alignment real on, there was never any static.

Some of the channels seemed to improve by replacing the rec/eq cards from another machine I was using for parts. But some didn't seem to improve until I de-oxited the connector that connects the headstack to the other electronics. And there is one that still does it sometimes... heh.

I'm not sure if mine has relays... but that's a good thought.

Well, I hope there are some ideas in there for you...

Roy

[mr. nick]

this was the issue i had, i replaced the relay, and all was fine.

mouser part # 653-G5V-2-DC5

n.

[sethl]

Thanks for all the tips everyone, I am planning on replacing all the relays. Seems like the consensus is that Omron G5V-2 24V relays are the correct replacement, but I note that there are two types of relays on the motherboard: One kind for sel-rep switching and the other kind to engage "record." Does this Omron part replace both?

Thanks,
Seth