In the 1980's I worked at a studio that had two MX5050s. It was my job to align them, replace heads (we used them a lot), and generally make sure they were meeting spec. I also maintained Ampex 350s, Ampex 440s, and even an old MR70 (huge!).
The 5050s did a great job on location recording, and were a go-to machine for voice-over original recordings (we did a lot of radio spots). I recall they had a switchable playback head, usually used for 1/4 track playback. We used the 440s for in-studio high-quality mastering.
It was a lot of fun working there (while a grad student in EE). Glad to see someone using them. Good job getting them running! I hope you can get tape!
Tom
How amazingly nostalgic for me >
In the 80's I worked in the technical/service dept. of the sole importer-distributor of all Otari products in Australia.
I was the guy that aligned & calibrated machines to any tape / SRL & EQ requirements. We had some big orders for the ABC.
I was also replacing worn heads + alignment. ( height, wrap, zenith, azimuth )
The 2 Ch. MX 5050's were indeed an industry 'work hoarse', always a pleasure to work on due to good Japanese quality.
After passing years, in a mastering position it became apparent that for old-decaying-shedding master tapes there was
one definite shortcoming of the MX machines, and that was the lack of rotating tape guides. Except for the 'counter wheel'
they are all fixed guides. This played havoc for tape-shed and is also why machines like the Studer A80 is superior for the
purpose of archival transfer re-mastering. I found it interesting that regarding age, two of the very best tapes were >
3M Scotch tape and EMI tape. (good luck for the Beatles) There was a very bad period of time for Ampex tape.
Years later I was the service & maintenance technician for a high-speed tape duplication plant > also Otari machines.
I was always a little amazed that tape bias frequencies were full-on radio frequency > The 32 X speed was 1 Mhz.
From memory, the 64 X speed was 4 Mhz. ( can you imagine the head-gap required for 15Khz becoming 960Khz ? )
Once again, the Master-drive and slave recorders were a pleasure to work on due to great Japanese quality & parts.
Anyway, this is a highly nostalgic thread for me