is there any way to adjust bias on otari 8 track?

[skullfisher]

hey y'all

so I'm still getting the hang of calibrating and aligning my new tank: otari mx-5050 mkIII, 1/2" 8 track.

is there a way to adjust the bias on this machine?

when I'm recording a 10khz tone @ 0db to each track, the REC BIAS screw doesn't affect the vu meters at all.

am I missing something? (uh, no sarcastic answers to that please!)

how does one adjust the bias levels on these beasts?

thanks

[The Ghost of FM]

I am not familiar with Otari calibration procedures as I don't own any of their equipment but, doing bias adjustments is normally a procedure of firstly turning the control down and then slowly turning it back up until you reach a reference level and then continue turning until the level drops by a specified amount of db, usually 2 or 3db.

Having a service manual for your Otari should step you through this procedure assuming that their documentation is written as well as the TASCAM service manuals are which give you a very specific step by step to work from.

If you have this documentation, read it and follow it to the letter.

If you are flying blind, consider contacting Otari for the book or a qualified technician to help you out.

Cheers!

[skullfisher]

hey ghost

I'm familiar with the bias setting process, that's how I set it when I calibrate my ampex 2 track machine... I usually drop it 3db after peak, because I'm using gp9 tape.

the problem I'm having is that REC BIAS screw on the otari doesn't affect the vu meters at all... kind of hard to find the peak level when the screw you're turning isn't causing the meters to react at all. they stay pinned at 0vu throughout the tone, while recording.

I'll try to contact otari, or fellow otari owners.

thanks!!!

[regebro]

Can it be that they are metering your in-signal while you do this? That would be normal procedure while recording, and the of course the bias wouldn't make a difference.

Hmm. It's been two years since I calibrated my Fostex. I'm rusty in the general procedure.

[skullfisher]

yes, this could be it!

I'll check it out right now, I was exhausted when I was working on it last night, I could very well have been monitoring input... d'oh!

[reel buzzer]

I have the manual for this machine if you want I can share what it says.

[skullfisher]

uh... I feel like a dolt, but I was monitoring from input instead of from repro... now the rec bias screw works.



but for otari users, do you set record calibration with SPL button engaged? or do you use the potentiometer and leave the spl button disengaged?

curious.

[reel buzzer]

Best to use the pots. I never had great signal using the SPL.