I recently picked up an Otari MTR 90 24 trk machine. I need to calibrate it. I need to set it up for 15ips and 30ips, I use Quantegy GP9 most of the time but also use 499 now and then. Do I need a calibration tape for each type of tape and calibrate it for ever session? Where would I find info about this? Thanks

Howdy,

You use an MRL tape to calibrate the playback levels - record levels are done with the tape you will be recording to. So, bottom line, you only need one MRL (with tones for 15 and 30 ips). You might want to do a little research on alignment procedures. I did a quick search and found this :

http://analogrules.com/align.html

You should consider having a tech do a complete alignment (including azimuth) first. Then they can make you an alignment tape and you can skip azimuth and just do levels on a session to session basis. It's better to have a real MRL tape, but you can get by like this and keep your machine in decent alignment for day to day use.