Multivox Tape Echo (just like Roland 201) has low output distorted echo

[eurekaiv]

Hi all, it looks like there are some folks around here familiar with these old tape echo machines. I have a Multivox MX-201 unit (nearly identical to the Rolands) that has a very distorted echo and low output. The reverb works fine and passes cleanly. I had it repaired for the same thing years ago but I've no idea what the tech did and I live all the way across the country now anyway. I got a schematic and attempted to audio probe the thing but the printing was so bad I could barely follow not to mention that keeping the unit on while apart and able to reach inside was nearly impossible. I also cleaned the heads to no avail. Any ideas? Or maybe someone can recommend a shop for repair in the LA/OC area?

[Gtr_tech]

Sounds like a bias problem to me....providing the playback head and assocoaited circuits are ok.

[52 Bill]

First things that I check are the tape and the heads.

How old and what condition is the tape in?

Have you cleaned and demagnetized the heads recently?

[jrfrond]

What 52BILL said: Clean and demag the heads, replace the tape and recheck. If you STILL have a problem, then you need a tech. This is the first thing any (good) tech would do.

I've done a good number of these units, and they sound much better when you replace the tape with GOOD audio tape like Ampex/Quantegy 499, BASF SM900, or something similar. If you CAN find a replacement tape for that, it is pretty ratty by now.

BTW- This is the ONLY way I fly if an echo unit uses 1/4" tape, no matter who made the unit. Most of the original tapes were garbage anyway.

[eurekaiv]

Cool... I'll try replacing the tape and doing a clean/demag and then report back. Thanks!

[eurekaiv]

Demag, clean, and replacing tape did nothing really. The echoes are still very distorted and it's not passing any dry signal at all actually. It's purely wet and very nasty. So I need a tech for it, preferably in the LA area. Anyone have any suggestions?

[jrfrond]

Look up Advanced Musical Electronics on Vanowen Street. Super shop! Ask for Ruth and tell her I sent you.

[eurekaiv]

Thanks for the tip! This place is even in a great location for me.

[Mars Amp Repair]

Agreed on all the first things to check ie:cleaning & such.

FYI, find an old 8-track tape at your local thrift store & use that to replace the existing old tape. It works just fine w/o spending too much dough. Be certain that the brown (oxide) side of the 8-track you find is not all worn out. Pick one that is a consistent brown & has no lines etched in it (that indicates it's probably very worn out).

Also the RE-201's had issues like most old electronics with the little electrolytic coupling & emitter bypass capacitors either shorting or opening or just degrading in value.

Signal tracing will usually ferret those things out. glen

[rf7]

Check out Valley Sound on Cahuenga Blvd. in No. Hollywood. We've fixed about 4 of those (tape echo machines) so far this year.