Can I make my own 30 IPS alignment tape?

[Benmrx]

Here's my idea.

I have an MRL for 15 IPS, but I really want to record at 30 IPS for a project coming up.

If I align my machine (Otari MTR90mkII) with the 15 IPS MRL, then record tones on a new reel, but record all the tones at 1/2 value, they'll be the tones I need when I switch the machine to 30 IPS.

For example. The common 1K tone. Once the machine is aligned at 15 IPS, and I record a 500Hz tone, it would (I think) play back as a 1K tone at 30 IPS, because I've just doubled the speed of the tape and therefore speeding the 500Hz tone up to 1K.

So, could I do this for my 1K, 10K and 100hz tones to create my own 30 IPS MRL?
Or am I wayyy off?

EDIT: My plan was to use Pro Tools as a tone generator (I have 24 outs) to create the 30 IPS MRL, anyone see that as being an issue?

[Mattct]

i am sure there is a studio in Seattle who will loan you a proper 30ips MRL. Once you align the machine from the MRL print the tones you just aligned on a new tape and you have a fairly accurate 30ips MRL to align from in the future.

PM me for studios that may loan/rent their MRL for a day.

[3rd world order]

scary.

i wouldn't go there.

[Benmrx]

Pretty quick replys. I guess that's a big

Thanks

[brianroth]

Jay McKnight (owner of Magnetic Reference Labs) is a good friend of mine, and I would say "buy the correct tape from him!"

We gotta support the folks who actually help us with things such as analog recorders.

However, if you read:

http://home.flash.net/~mrltapes/choo&u.pdf

...Jay tells you all you need to know in order to use a "wrong" MRL alignment tape.

If you're on a tight budget, I suggest the "short" alignment tape with a chromatic sweep.

Bri

[dbbubba]

You can use an improper speed MRL tape if you use Jay's table.
It'll be close enough, but you need to buy a proper tape.

You can't make your own tape because any inherent probelems with your machine will just multuply.
It is called a reference STANDARD because you are referencing to a standard set by MRL which is a very controlled set of parameters.
You can't really use the machine that you are aligning as a it's own standard.

Also, all you really need is a short alignment tape with 10k, 1k and 100hz to align almost ANY analog deck. It is nice to have middle freqs. like 2.5k and 5k when aligning decks like an Ampex ATR102, but most decks just require those three. A short tape should cost under $350.00 new from MRL.

A sweep tape is kinda' difficult to use on a mutitrack.

Also, the longer the sections with tones are, the longer the tape will last and be accurate. If you have to keep hitting autolocate to go to the beginning of a freq. section then you are running the tape that many times! You can't just say that you used it once... no, you ran the tape over the heads more than once!

Soes STL still exist?

Danny Brown

[Jim Williams]

Can you record a full track alignment tape with fringing compensation?

Jim Williams
Audio Upgrades

[Bob Olhsson]

I had an interesting experience with this issue when we bought a new 24 track machine for the Quicksilver Messenger Service studio.

I insisted that one of the former Wally Heider technicians perform the initial tape path alignment on the machine. We quickly determined from the level of instability that tape had been run on the new heads without them being properly aligned. (This is equivalent to running brand new tires on a car without a steering alignment or wheel balance. The dealer got to eat most of their profit paying for the replacement set of heads.)

Now that we finally had a new machine that was working properly, something the tech from the dealer had never seen before, we made ourselves a set of tones for 15 and 30.

We had a number of projects in from the major LA rooms and I was pleased to see their tones almost perfectly matched our tones. Unfortunately this wasn't the case with the local mid level San Francisco rooms. Virtually every set of tones we got in no matter which local studio it came from had the very same tracks all screwed up and this tone "virus" continued for years without anybody noticing or, obviously owning an alignment tape!

[Norman Lindsey]

So, could I do this for my 1K, 10K and 100hz tones to create my own 30 IPS MRL?
Or am I wayyy off?

yeah i think it might just be fine. there's no harm in trying , and if the tones are ok at the higher speed you know it's all been trimmed.
look at the edge tracks the most. i.e tracks one and twenty four.

[Benmrx]

Originally Posted by Jim Williams

Can you record a full track alignment tape with fringing compensation?

Jim Williams
Audio Upgrades

Please excuse my lack of knowledge here, but what is "fringing compensation"

And thanks for everyones input.

BTW, when I use my 15 IPS MRL everything seems fine. I've had tapes start at my place and go somewhere else and the tones always seem fine.

I'm thinking about taking Mattct's advice and borrowing or renting a 30 IPS reel from a local studio, and just get my own when I have some extra cash.

[brianroth]

Originally Posted by dbbubba

You can use an improper speed MRL tape if you use Jay's table.
It'll be close enough, but you need to buy a proper tape.

You can't make your own tape because any inherent probelems with your machine will just multuply.
It is called a reference STANDARD because you are referencing to a standard set by MRL which is a very controlled set of parameters.
You can't really use the machine that you are aligning as a it's own standard.

Also, all you really need is a short alignment tape with 10k, 1k and 100hz to align almost ANY analog deck. It is nice to have middle freqs. like 2.5k and 5k when aligning decks like an Ampex ATR102, but most decks just require those three. A short tape should cost under $350.00 new from MRL.

A sweep tape is kinda' difficult to use on a mutitrack.

Also, the longer the sections with tones are, the longer the tape will last and be accurate. If you have to keep hitting autolocate to go to the beginning of a freq. section then you are running the tape that many times! You can't just say that you used it once... no, you ran the tape over the heads more than once!

Soes STL still exist?

Danny Brown

On the high end, I would want to have 5k, 10k, 15k and 20k as a minimum. 100 Hz on an alignment tape is often useless if the tape isn't compensated for fringing. For that matter, I never even use any tones below 1k on an alignment tape (except sometimes to search out a failure, and here a flux loop can be an even better tool) and instead do the LF EQ tweaks during the record step, per the procedure that Jay McKnight outlines in his various papers at the MRL website. That is how I was taught to do it back in 1972, and Jay still concurs! <g>

What I referred to as a "chromatic sweep" tape has a series of "do re mi..." tone steps versus fixed steps at 1k, 2k, 4k, etc. I like the chromatic sweeps.

Once a given machine "has been dragged kicking and screaming" into an original decent alignment condition (THAT is where the ful- length tapes come in handy), then the shorter tapes will work just fine.

Bri

[brianroth]

Originally Posted by Benmrx

Please excuse my lack of knowledge here, but what is "fringing compensation"

And thanks for everyones input.

BTW, when I use my 15 IPS MRL everything seems fine. I've had tapes start at my place and go somewhere else and the tones always seem fine.

I'm thinking about taking Mattct's advice and borrowing or renting a 30 IPS reel from a local studio, and just get my own when I have some extra cash.

Read through Jay's papers at the MRL website, particularly:

http://home.flash.net/~mrltapes/choo&u.pdf

Amongst other things, it describes the fringing effect.

Bri