Tape Machine Calibration Questions

Matt C.

New member
Hi, i have a couple quick questions about calibrating/aligning a tape machine (in my case a Revox B77 mk2):

- i know i need some kind of tone generator to feed into the tape machine. if i use my computer, do i still need another seperate device to confirm that the tone is being sent at the proper level? or is there some trickery around this that would allow me not to buy another piece of testing gear?

- how does my choice of tape affect how i calibrate the machine? is it only a matter of changing the bias, or are other parts of the calibration affected by the type of tape?

thanks very much for any help!
 
i know. but don't i also need a way to feed tones to the machine from an external source?

You must calibrate the playback side before doing the record side. To do this you need:

1. a proper test tape
2. a metering device that is accurate throughout the frequency range
3. an oscilloscope set for "x/y" display
Add tone generator to the above only when calibrating the record electronics.
 
i do have the service manual for the deck.

i will be calibrating both the playback and record electronics, so i DO need either a stand alone tone generator, or an accurate meter put between my computer (being used as a tone generator) and the tape machine to confirm the tones are at a proper level?

where would i get such a meter?

also, in an older thread someone recommended using a program called WinScope (i think) instead of buying an actual oscilloscope. anything to watch our for when doing this?
 
i do have the service manual for the deck.

i will be calibrating both the playback and record electronics, so i DO need either a stand alone tone generator, or an accurate meter put between my computer (being used as a tone generator) and the tape machine to confirm the tones are at a proper level?

where would i get such a meter?

You need the meter either way. The meter is put on the output of the deck so you can make certain the "O" is accurate @ all frequencies. Many machine meters are notoriously inaccurate in this regard. TASCAM meters are particularly useless.

I use a TEAC/TASCAM MB-20 meter unit which is accurate throughout the spectrum @ 0.


also, in an older thread someone recommended using a program called WinScope (i think) instead of buying an actual oscilloscope. anything to watch our for when doing this?

Anything that will do an x/y display will work. You need that to set azimuth on the play & record heads.
 
would it work to run the tones through the meter bridge on my Mackie 8 bus? or are those meters not accurate enough?
 
Are they segmented LED meters? If so, they won't work, at least not if you want to be accuurate...if they are analog then you need to borrow a multimeter like a Fluke 83/85/87 or some reasonably accurate true RMS multimeter that will handle 20Hz ~ 20kHz bandwidth and calibrate/document the Mackie meter response at key frequency points...that's the only way to know unless you call Mackie and talk to a tech and they actually know what it is that you are trying to do/know and their standards coincide...
 
thanks for the help everyone. i think i have the whole process pretty much figured out now, i just wanted to make sure i didn't end up throwing down a bunch of cash for testing equipment i didn't absolutely need.
 
After you learn how to do it. Do it. And do it often. At least, when ever you change tapes.

Put a record pad on each tape and dial in you stuff.

On a side note. While I love the analog compression that tape puts on lower frequencies. I find that I need to get it off the tape and in the computer as quickly as possible. By morning, I'll notice a loss in sound mass. Small, but it's there. Magnetic tape looses is magnetism in a constant stream. And my work is sitting there amongst that magnetism. Little bits of my music going off into space. By morning, I can notice it.


:cool:
 
On a side note. While I love the analog compression that tape puts on lower frequencies. I find that I need to get it off the tape and in the computer as quickly as possible. By morning, I'll notice a high frequency loss. Small, but it's there. Magnetic tape looses is magnetism in a constant stream. And my work is sitting there amongst that magnetism. Little bits of my music going off into space. By morning, I can notice it.


:cool:

Dang. You gotta be joking !! You are, right ?
 

You might consider getting some ear muffs and putting your ears to bed. . permanently. And maybe take up reading really quiet books. Otherwise, I can guarangintee that in 10 years you'll be just like every other musican and even most people I have ever known. Partially deef.

I guess you must hate MP3's.
 
Back
Top