Looking for advice on long R-2-R tape

[WayneZworld]

Hi Tapeheads,

I have been lurking for a while; this is my first post on your board. You guys have a great forum!

I’m an old vinyl R-2-R guy that lost my way with DAT / CD’s / SACD’s / DVDAudio’s, or maybe technology in general. The good news is I’m back.

About a year ago I started to listen to some old vinyl on an old Mitsubishi LT5 vertical linear dive TT with a Shure V15 type V, that combo sounded good enough to make me realize that vinyl did things for me sonically that other sources could not so I;

A. Upgraded to my bother in laws mint (circa 1981) Oracle Delphi AC with a Blue Point cartridge.

With this combo and some better vinyl like MOFI Masters, MOFI Gain 2, and 45 RPM LP’s I realized analog rules! But I also realized the Blue Point was the limiting factor on the Oracle so I;

B. Purchased my friends Koetsu Black; that really took the sound up a notch, but at hi SPL’s the old GST-801 tone-arm oscillated and skipped.

Although the Delphi AC with the Koetsu Black sounded much better, due to limited TT locations I was not able to adjust / isolate it from SPL induced oscillations, so I did what any other nut would due;

C. Bought a new Oracle MK VI with a Thalia, and 345 tone-arm.

This combo puts a tear in my eye every time I listen to it!!

Now my dilemma; I want to make some compilation tapes but my Tandberg 64X is shot and after several failed attempts at purchasing a new “old” R-2-R I decided buying used required concessions that I was not prepared for, so again, I did what any other nut would due;

D. I purchased a brand new Otari MX-5050BIII from Otari / AheadTeK in CA.

I broke the Otari in with a few reels of RMGI 911 10.5” 2500’ tape and boy does it sound sweet, even at 7.5 ips!!!!

1. I would like to buy some longer tape like the RMGI ELP LPR 35 3600’ but is it as good?
2. Is there any other tape that is longer than 3600’ that can be used on 10.5” reels?
3. What are the down sides of thinner tape?

Wayne

[Pentium100]

...

1. I would like to buy some longer tape like the RMGI ELP LPR 35 3600’ but is it as good?
2. Is there any other tape that is longer than 3600’ that can be used on 10.5” reels?
3. What are the down sides of thinner tape?

Wayne

1. I don't know, the tape is way too expensive for me to even buy a single reel for a test.
2. Depends on the tape deck. You could fit ~2km of double play tape or ~3km triple play tape, but...
3. Thinner tape stretches and breaks easier, also it has higher print trough (though I have never heard genuine pre-echo on a triple play reel tape or C120 cassette; probably because my equipment is of lower quality and has higher noise).

[dreamsound]

According to RMGI's site, LPR35 is the long play version of 911. Meaning same magnetic formulation, but on a thinner backing, that's how you get 3600' on a reel. LPR would probably break easier when your 5 year old finds it, and feel a little lighter if you handle it with your fingers vs 911...but that's about all I think any home stereo user would notice. Should sound virtually the same.

http://www.rmgi-usa.com/rmg_studio.html

Also, not sure if you know or not, but RMGI, Emtec and BASF are supposedly all the same formulations of tape. Apparently the formulations survived through a few company name changes..I've gotten some lightly used 1/2" Emtec 911 off of ebay & it was great stuff.

I've never heard of anyone getting more than 3600' on a 10.5" reel. I have heard of 12" & 14" reels though. Don't know where you'd find them in 2010 though.

I purchased a brand new Otari MX-5050BIII from Otari / AheadTeK in CA.
*Hi5*
Very cool!!

I'm really trying not to be rude & ask what the final $ amount was, so I won't ask.....but I will let you know that I'm really curious.

todd

[Kent T]

Congratulations on your new Otari MX 5050B III. I own a MX 5050 B II myself in very excellent condition with low hours. RMGI LPR-35 is a thinner version of SM 911 to accommodate the longer playing time. It is 1 mil tape. There was in the past some 1/2 mil thick tape stock but it is delicate and has lower output and is more prone to print through. Welcome to the Otari Family! Glad to see you here on these forums! *reelspin*

[Des-Lab]

You stick with 1.0 mil tape like LPR-35 and you should do just fine. Especially in light of the fact that you shelled out for a new Otari. Last time I checked, the list price was in the USD$5500 ballpark. So cutting corners by seeing how much tape you can cram onto one reel makes little sense, financially or otherwise. Although I should point out that you still could've gotten a gorgeous plug-and-play X-2000R for probably less than half that. But no matter, You got what you wanted and that's what's important here. I can't for the life of me imagine how you could be dissatisfied with any recording made at half track on a new tape even at the "slow" 7.5 ips.

So to answer your original question, the longest possible tape on one 10" reel I can conceive of would be to try and track down some .5 mil tapes and splice them together. Maxell made a UD 18-180, which was 3600 feet of tape wound onto a seven inch reel. Quantegy made one as well. I don't positively remember the model number, but I want to say it was #661.

Splice two of those babies together and the result would be a staggering monster of a tape 7200' in length. Just under three and a half hours for one pass at 7 1/2 ips.


But the fidelity?

You won't be pleased.

The reliability?

Under no circumstances should you ever, EVER fast wind it.

[akainix]

the down sides of thinner tape

OK you are using a high output tapedeck with 320nW (or more???)
commercial recorder are build for thick tapes (Ampex 456 and so on)
If you are using thin tapes "the power/strength" of your record head "will blow the tape" - they are build for about 180nW. The THD will rise.
You have to readjust the recorder when you want best results in THD and noise. Years ago i have tryed to use a BASF LGR 50 (german broadcast tape) with an AKAI 747. I needed weeks to ajust my recorder but then it was ok.
AKAI 747 it not the best for those "special adjustment" - I heard your Otari
is able for 3 tape - adjustment at the same time. Read the instruction.

[Pentium100]

...

OK you are using a high output tapedeck with 320nW (or more???)
commercial recorder are build for thick tapes (Ampex 456 and so on)
If you are using thin tapes "the power/strength" of your record head "will blow the tape" - they are build for about 180nW. The THD will rise.
You have to readjust the recorder when you want best results in THD and noise. ...

Can't you just record the tape at a lower level instead of adjusting the tape deck to show 0dB at 180nWb/m?

A bit unrelated question - is Akai 747 set for 320nWb/m by default?

[dreamsound]

If you are using thin tapes "the power/strength" of your record head "will blow the tape" - they are build for about 180nW. The THD will rise.

Ahhh...boy. *eyepop*
1.) Tape thickness is not indicative of it's operating level...ever. Quantegy 406 is 250nw/m and thicker than LPR35. 911, GP9 and 406 are all the same thickness, but GP9 is 520nW/m and 911 is LPR35's twin. If you want a real eye opener, research DSM 931 tape.

Thicker=higher operating level isn't true.

2.) LPR35 is a 320 nW/m reference level, not 180.
http://www.rmgi-usa.com/pdf/RMGI_LPR_35.pdf

Years ago i have tryed to use a BASF LGR 50 (german broadcast tape) with an AKAI 747. I needed weeks to ajust my recorder but then it was ok.


*headache**headache**headache*

Trying to "adjust" any recorder correctly requires an alignment tape, or a flux loop with a known magnetic strength at certain frequencies. It's that simple. No 'tinker by ear' method can EVER tell you how hot the magnetic level is at the heads, or on a tape......which is what ALL of the electronics you do hear are adjusted for. The magnetic level on the tape is the foundation of the entire machine's adjustment. Can you hear a magnet?

With an alignment tape, it would take a complete newbie 1-2 hours to get a 2 track recorder right, not 2 weeks to get way off in left field. After you get the swing of it & learn the db's & nW/m's, aligning a pro flavored 2 track machine shouldn't take longer than 15 minutes. Something like a GX747/909/X2000R might take longer because the covers could be in the way of the adjustments.

Sorry...rant over.

todd

[dreamsound]

Can't you just record the tape at a lower level instead of adjusting the tape deck to show 0dB at 180nWb/m?

If you set 0dbVU at 185, you're giving up 6db in signal to noise (with LPR35, 9db with tapes like 499) just by staying at 185. Put 0dbVU at 320 and your noise floor moves 6db down...at least that's the theory. In reality it isn't always a 6db drop, but it does drop quite a bit. What happens is the playback electronics don't have to use as much gain to get the tape level to the line level...because the tape has more signal to start with.

Recording quiet won't hurt anything, other than not having the improvement in S/N that you could have.

todd

[Pentium100]

If you set 0dbVU at 185, you're giving up 6db in signal to noise (with LPR35, 9db with tapes like 499) just by staying at 185.
...


I meant differently, that is, if my recorder is set for 320nWb/m = 0dB and I have a tape that was made for 180nWb/m, I can do one of two things:
1.Get a new alignment tape, adjust the recorder so it shows 0dB at 180nWb/m, record the blank tape with meters showing 0dB.
2.Leave the tape deck as is and just record the tape with meters showing -6dB (or whatever the equivalent would be).

In both cases the magnetic field strength on the tape should be the same, the difference would be just what the meters show me.

Or would the be some other difference I did not think about.

[dreamsound]

Oh..sorry..I got it bass ackwards.

The short answer: yes....mostly.

The only reason there's a "mostly" there is because your electronics are pushed 6db off their optimum operating range. I don't think an Otari would care a whole lot really, but I could see where that's a big issue with an old 1950's sears battery powered machine.

give it a shot, see what it does.

todd

[Pentium100]

...
give it a shot, see what it does.


My tape decks are not level aligned because I do not have the alignment tape, so I can't test it for sure. I also don't know if I have any 180nWb/m blank tape. Svema B-3715 seems to be made for 320, Zonal 844/845 probably too and Orwo 131 (triple play) sounds OK at the regular levels, so it probably means that my tape decks are set for 180, or maybe somewhere between 180 ant 320.

OCL X064P (double play tape) is probably made for 180, but it probably needs much less bias current then all the others, because it has low levels of high frequencies and very low sensitivity (around -7 compared to Svema B-3715).

[dreamsound]

I dunno where you'd score an alignment tape on another continent. However, as a 'better than nothing' idea you might give the flux loop idea a shot:
http://www.manquen.net/audio/docs/Magnetic%20Recorder%20Testing%20with%20a%20Flux%20 Loop%20w%20pictures.htm
I built one on the end of a popsicle stick with some electrical motor wire and a pair of resistors a couple years ago. Aligned the deck, built the loop, plugged the loop into the sound card & then went experimenting to find what levels made the deck go to 0VU. Worked fine & didn't require the alignment tape to reset the deck anymore.

However, without the alignment tape to get levels right in the first place, you're stuck working out the math & hoping the application of the magnetic field is perfect...which it probably won't be...but it could be relatively close. Here's a thread with the math in it:

http://www.physicsforums.com/showthread.php?t=149088

Dunno if that helps you or not...

todd

[Pentium100]

I dunno where you'd score an alignment tape on another continent.
...

ebay id 260567650632

I don't know if these tapes are of the highest possible quality, but I don't need absolute precision and the price seems kinda reasonable. Too bad they don't make cassette tapes.

I have an azimuth tape made by them, seems OK.

But I think that I should get a good oscilloscope or AF voltmeter first, since the service manuals usually specify "set the playback gain so that at the reference level the output is x mV".

But I think I should stop derailing the thread now...