Just been thinking about MRL tapes........what have I missed?

[altruistica]

I've just been thinking about MRL tapes as I need two to set up my MS16 and MSR16.

If someone's machine is all set up using an existing MRL tape, and they recorded tones like the ones on an official MRL tape, what's to stop another user using that tape as if it were an MRL tape? Where have I gone wrong with this thinking? Suffice to say, the 're-created' tape would only be as good as the original machine's setup, but if that wasn't within spec, then what's the use of having a standard (or two, or three....)? I can see that if you did this a few times, any errors creeping in would be additive and would render the thing pretty useless, but from a 'one generation' perspective, what would the error rate look like?

Cheers
Al

 

[miroslav]

Suffice to say, the 're-created' tape would only be as good as the original machine's setup...

That's really it.

MRL tapes are made on precisely calibrated machines, checked for consistency/quality etc.

When you set up your machine, you are attempting to match the spec of the tape, and many old/sued machines will only come so close.
Making tones after you calibrate YOUR machine is good for YOUR machines....but it's still not the same spec as an MRL tape which can be used to calibrate other machines.
You would be introducing whatever anomalies your machine added to the tape.

 

[mdainsd]

And MRL tapes are recorded full track, not individual, which would introduce even more issues...

 

[Beck]

Suffice to say, the 're-created' tape would only be as good as the original machine's setup.

As miroslav said, that's really it... but it is possible to make a cal tape from a perfectly aligned and functioning machine... if that machine was setup expertly using an MRL cal tape.

The problem boils down to quality control. Would you bet your machine's performance on a homemade tape of dubious origin? There are tapes like this being sold on eBay, but the makers/sellers know just enough to be dangerous. Even though it seems costly it is a wise investment to stick with MRL and other professionally made cal tapes from STL, BASF, TEAC, Fostex, etc.

So yes, technically speaking you can (and in time past could a lot easier) walk into a professional studio and have them make a cal tape for you at low cost using your own blank tape, but in practice, especially now days there are a lot of potential gotchas!

And as mdainsd pointed out MRL and other brands of cal tapes are recorded full-track. They don't always have to be, but only if the heads from machine to machine are the same.

TEAC actually made a special tape that was used in the head height phase of setup for new 1/2" 8-track machines that was recorded as individual tracks, but normally you want to use full-track. That special tape would work for the Tascam 38, 48, 58, TSR-8, and Otari MX5050-8 because those machines use the same track spacing. But it wouldn't work on 1/2" 16-track of course.

 

[altruistica]

What exactly does 'full track' mean?

 

[Beck]

What exactly does 'full track' mean?

It means there is one wide track across the whole width of the head. So MRL and others have special heads on the machines they use to make the cal tapes. There are no breaks between tracks no matter what size the head. This why the same tape can be used on 4-track, 8-track, or 16-track machines of the same tape width. So for example, The correct tape for the Tascam TSR-8 is also correct for the MSR-16.

 

[altruistica]

Cheers Beck, Got it now.
Al

 

[miroslav]

Once you calibrate your machine with an MRL tape....by all means, get a fresh reel of tape, and then print tones on it same as the ones on the MRL tape, across all tracks (you can't do full track, so just record it on all tracks)....then save/use that tape when you want to do spot-checks, and save the MRL tape for those full calibration times.

 

[Beck]

Once you calibrate your machine with an MRL tape....by all means, get a fresh reel of tape, and then print tones on it same as the ones on the MRL tape, across all tracks (you can't do full track, so just record it on all tracks)....then save/use that tape when you want to do spot-checks, and save the MRL tape for those full calibration times.

Yep exactly, and that is a tried and true way to gauge wear and drifting on that one machine from one full calibration to the next.

 

[chronicle]

Yep exactly, and that is a tried and true way to gauge wear and drifting on that one machine from one full calibration to the next.

Ok guys. Total ignoramus here when it comes to this calibration stuff. Guys, I have lot's of questions regarding this calibration thing. But I'll ask them on my own thread which I'll post later today. Look for it. I really need help.
Thanks.