Otari MTR-90 MkII alignment

[Sput]

Hi Folks!

I've being recording on tape for a year now, using RMG900 at 30ips. I have my machine calibrated at 0, with a MRL 250 nanowebbers tape.
It sounds good to me, but sometimes I feel that I want to push it a little harder to get rid of some hiss or to get that great electric gtr sound or with room mikes and other stuff.
Sometimes I'm recording to PT after tape so I can't go too wild without cliping the input of my converters.

I was about to realign my Otari at +3, and some friend told my that it might be too much for it to handle (referering to the bass). I had heard of this before, but never actually experienced it with my machine. I'm aware it also depends on the kind of tape that I'm using.

Can you guys share your experiences on this?
Are RMG911 or ATR tapes a better choice to address this?
Should I just leave it at 0 and recalibrate my converter inputs?

Thanks very much in advance! thumbsup

[Sput]

Maybe my question wasn't very clear. I'll try again:
Is the Otari MTR90mkII well suited for high output tape?
I've read in some threads that Studer and Ampex are better suited for those.
They even call Otari "prosumer" tape machines.

Of course I have to decide myself on the sound that I prefer, but I don't want to buy every high output tape I can lay my hands on only to discover that I should have spend my time and money on another kind of tape.

Thanks again!!

[Fletcher]

Originally Posted by Sput

I've being recording on tape for a year now, using RMG900 at 30ips. I have my machine calibrated at 0, with a MRL 250 nanowebbers tape.

Yes, you can easily go to -3 or -6 on the meter when you're using a 250nWb/m reproducer test tape... it'll push the tape a little harder [so you'll want to watch the level at which you're printing] but will indeed drive the overall noise floor down by a fair measure.

At -3 you will have a 3db>250nWb/m alignment [often called +6] and at -6 on the meter you'll have a 6db>250nWb/m alignment [often called +9] which RMGi 900 can handle easily.

Again, be conscious of the levels at which you're printing and the "MOL" (maximum operating level) of the tape as otherwise you can get the transients to crap out... you should also probably work with some kind of PPM (peak program meter) for a while so you can figure out just how hot you're printing signal from transient heavy instruments [like drums].

Often you can see a kik drum register at -10 on a VU meter [which stands for "volume units", which is an average of the level of the signal] when in fact you're printing the front end transient at like +15... with a PPM meter you can get an idea of the actual level of the transient and record appropriately.

BTW, get your machine's tape path checked by a professional (like every 6 months)... this is one of the most common causes of machines not sounding good.

Peace.

[dbbubba]

I have run a MTR 90 II at +6 and +9 over 185 nWpm for years without any problems.
As long as your tape is the correct type you will have no problems.

I would not call an OTARI "pro-sumer" but they do have a more "Japanese" sound due to the electronics.
They just are not as robust sounding as an Ampex or MCI and don't have the sound of a Studer either.
I have done many good recordings on OTARI MTR90 IIs.
They handle tape very well when the transport is functioning 100%.

As far as running at +3 over 185 nWpm goes...
Elevated level tapes like 456 that allowed everyone to push levels up to +6 over 185 nWpm came out in the late '70s.
In the days before +6 tapes people ran Dolby A to keep +3 recordings quiet enough to be useful.
So, if you are running at +3 you are basically using a FORTY YEAR-OLD tape level standard!
I have tapes from other studios that presumably had staff that knew their stuff that were recorded at +3 over 185 nWpm in as late as '93, but they were banging the tape pretty hard.

The issue of tape machine levels causing the inputs to digital interfaces is a whole different topic.
No... the manufacturers of A/D manufactures absolutely missed the boat in this area.
I am not completely sure if it relates to the A/D chip sets that they use or what.
With a Pro Tool HD interface you can use the trim pots.

I just dial back the output of any offending channels on my JH-24.
It isn't that big of a deal.
With digital it is all much less critical than when recording to a medium like tape where the recording level and how hard you are hitting tape effects so many things.

[Fletcher]

Originally Posted by dbbubba

As far as running at +3 over 185 nWpm goes...

If you read the original post, he's already running a tick (like 1 or 2 10ths of a db] under 3db>185nWb/m as he's using a 250nWb/m reproducer test tape.

[kats]

The point being is that he is running his tape machine soft and the advice of his friend is dead wrong. He's operating at 250 nanowebers at 30 IPS. He can EASILY go +3/250 (I'd go higher personally).

PS on the OTARI. I have one in perfect order sitting beside an A827 in perfect order - I don't think the Otari sounds any worse than the Studer. Both are pretty much vanilla to me. I've never used a JH24, but out of all the above, don't they have the least flattest response (with an exceptional low end boost)? Maybe that accounts for the extra girth you notice?

Oh and PS on the Otari, do not use the "auto low frequency alignment". Do it manually, and better yet send a lower tone in there besides 100hz (I was once recommended 63Hz).

[theatomicgarden]

ive been running tape for a year, too. also on an mtr-90 ii. im using rmg 911 at 15ips and then dumping to pro tools.

i was having the same issue (not being able to hit the tape hard enough due to the hot converter inputs), so i trimmed my 192 inputs by 3 db and it gave me the headroom i needed to hit the tape as hard as i want and get a reasonable level in pro tools.

and, like fletcher said, learning the relationship between the pro tools meters and the machine's meters has been a huge help in gauging whats actually coming in.

[Sput]

Tons of great info for me here! Thanks very much!!

Fletcher, I usually use the meters in PT as my peak meters. Actually I track at VU levels based on a post that you wrote here in GS, and go from there. That post pretty much saved the first record that I did on tape. Thanks again in retrospect!
One more question, RMG900 and ATR have high output levels, right? Does that mean that I can push them harder? And go lighter with something like a RMG911? Please excuse my ignorance.

dbbubba, I use apogee and RME converters, not Digi. But I can certainly trim back whatever channel is clipping. I just rather find a way to work at nice levels without to much concern.

Kats, I'm very glad you think the Otari is a good machine. I have used other machines (Otari MX80, Studer A800, A820) but never at my studio. When you compare recordings made in different enviroments there are just too many variables. The room itself certainly plays a more important role than the recorder. That being said, the best recording that I remember was made in a A820, but that's probably because I didn't engineer it!!!

Ok, so tomorrow I'll go +3 on the rec gain and -3 on the rep gain and let you guys know my impressions.

Good night fellows!

[Sput]

I finished a recording at +6 (3db>250nWb/m). It sounds same good and I seem to still have headroom for days. Actually I'm considering going +7. Well, not a great difference probably, but I don't wanna clip my converters.
You know, I recorded drums at a modest voltage and the transients are perfect. My only problem (not really) is with my selfmade NS10 outkick and bass amp mics. The go wild in the VUmeters, but peak really low in PT.

Thanks very much for your advice, mates!

[kats]

Originally Posted by Sput

Ok, so tomorrow I'll go +3 on the rec gain and -3 on the rep gain and let you guys know my impressions.

Good night fellows!

Unless I missed something, shouldn't you go -3 dB on the repro (you have a 250 nWbr/m MRL) and 0 on the record gain (as opposed to +3)? That would yield you a a +3/250 nWbr/m alignment (or approx. +6/185)

[stellar]

an important question in this equation is whether or not you are using noise reduction

[Sput]

Originally Posted by kats

Unless I missed something, shouldn't you go -3 dB on the repro (you have a 250 nWbr/m MRL) and 0 on the record gain (as opposed to +3)? That would yield you a a +3/250 nWbr/m alignment (or approx. +6/185)

Yeah, totally. My bad.

[Sput]

Originally Posted by stellar

an important question in this equation is whether or not you are using noise reduction

No, I'm not. And that's one of the concerns for going +6. To be completely honest, I don't really mind a bit of hiss, but some clients do.

[Jim Williams]

Originally Posted by dbbubba

I would not call an OTARI "pro-sumer" but they do have a more "Japanese" sound due to the electronics.

Otari uses RC4558 dual opamps, a 1 v/us slew rate. With the massive amount of HF boost EQ needed to record to analog tape, those opamps run out of loop gain real fast. Therefore the top end is both cloudy and dirty. Running higher levels makes it even worse are the opamps run out of steam even faster. Replace those with opamps with higher loop gain, lower noise and THD and those problems are gone. The LME49860NA is a great swap.

Jim Williams
Audio Upgrades

[Sput]

Originally Posted by Jim Williams

Otari uses RC4558 dual opamps, a 1 v/us slew rate. With the massive amount of HF boost EQ needed to record to analog tape, those opamps run out of loop gain real fast. Therefore the top end is both cloudy and dirty. Running higher levels makes it even worse are the opamps run out of steam even faster. Replace those with opamps with higher loop gain, lower noise and THD and those problems are gone. The LME49860NA is a great swap.

Jim Williams
Audio Upgrades

Hey, thanks! That's sounds like a great advice! Is it just a question of replacing one for the other or do I have to do something else?
I guess I can replace that myself, even though the most difficult task I've been able to do so far is soldering mic cables! Thanks god the other guys at the studio are McGyver-like!!

[Jim Williams]

Some opamps will require some feedback phase lag caps added. Some will also need .1 uf local psu bypass caps from pin's 4 and 8 to ground. You need a scope to check the work. Have McGyver do it for you. Then replace all those green chicklets mylar EQ caps with Wima polypropylene film and it will sound very pro.

Jim Williams
Audio Upgrades

[Sput]

That sounds like a job for McGyver for sure!
Me no comprendo...

Thanks for your kind advice, Jim! Be sure that if there wasn't some thousand miles between us, you would be the one updating my machine!

[superburtm]

Hey gang I recently bought an mtr 90 mrk2. Anybody know where i can get a manual an alignment instructions? I'm going to be using Atr tape and I got an Mrl for +6 15ips IEC @355nwb
and 30ips aes. I have the remote but no autolocator, I'd like to get one if anyone knows where I can get one. Thanks!!

[Fletcher]

No locator? Wow - that's gonna suck... you'll probably need to hire a "tape op"!!

There is no secret to aligning an MTR-90 mkII... unless you're totally new to doing alignments in which case you're going to need to hire a tech to make sure the transport is set up correctly [this is absolutely imperative with an MTR-90 mkII as its a "capstanless transport" which is far more critical in terms of tape path tensions (which are still very important) than machines with capstans].

When you hire that tech to set up your transport - have them teach you how to do an electronic alignment [its not hard, just tedious... especially without a locator!!].

Peace

[Jim Williams]

Originally Posted by Sput

That sounds like a job for McGyver for sure!
Me no comprendo...

Thanks for your kind advice, Jim! Be sure that if there wasn't some thousand miles between us, you would be the one updating my machine!

I sent out an MX80 card a couple of weeks ago. I used 22 volt National LME49860NA opamps as the power rails are + - 20 volts, only a few opamps will run that hot. Another benefit was I removed most of the bipolar el coupling caps for a much clearer top end and fatter low end. Even the playback head is direct coupled, nice and clear, no more Japanesey sounds...

I find most of these analog decks begin to sound much more alike when they are rebuilt like that. The sonic differences are reduced so it's all tape you hear.

[superburtm]

Hey guys...I have a tech friend named Marko Fox helping me install my console and tape deck. He said he aligned the otari MTR 90's aa bunch back in the day( I have an MTR 90 mrk 2) but isn't sure how to switch it to CCIR. Can anyone shed any light on that? I'm assuming it's on the master bias card labeled 7. Thanks!

[15ips]

Super -

I think you are right, take a look at the master card for your machine. There should be a NAB/IEC dip switch, I know there is on the main card of the MX80.