Messages

1

Reel to Reel Tape Machines / Otari MTR-20 -- Keep or Sell?

« on: June 12, 2012, 09:47:34 AM »

Folks:

Can anyone report their experiences with the Otari MTR-20?  I'm trying to figure out what to do with the one I have -- put it to good use or sell it?

This machine represents the industry's *final* push for studio mastering decks, sometimes compared with the Ampex ATR-102/4 or the Studer A820 (or maybe the Nagra TA, which is 1/4" only.)

It is sophisticated and robust 1/2" machine with 4-channels of electronics and can handle 14" reels but , alas, typically appears on the market with only its 4T 1/2" headblock.  (For my machine, I've got new 2T 1/2", 4T 1/2" and CTTC 1/4" headblocks -- where today's $10K Nagra TAs only have the CTTC setup.)

I'm told that only 200+ were ever made (which is why I have the essential parts of a 2nd machine as spares), so experience using them is probably limited.

Should I keep it or let it go into someone's studio where they can really use the 2-track 1/2" heads and auto-calibration capabilities?

If you'd rather discuss than post, call me at 212-699-0755.

Thanks,

Mark Stahlman
Brooklyn NY

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Reel to Reel Tape Machines / Re: The R2R machine used by the Fine's for your collection

« on: February 10, 2010, 08:39:06 PM »

Rich:

Mark Levinson told me that he used standard 1/2" B&K 4163 capsules w/ 200V polarization and "modified' 2804 battery powered supplies.  So, no RF circuitry was involved in that setup.  These are omni-patterned, like the DPA mics many prefer, and lend themselves to widely spaced placement for recording ensembles.  Kostas Metaxas famously used 1/4" instrumentation capsules for many of his Stellamaster recordings, sacrificing S/N (i.e. self-noise) for the "speed" he got with 100kHz frequency response.

Of course microphone choice/placement is an art and there are many who do not enjoy the results from these omnis.  I happen to like the open sound of the 1" instrumentation capsules myself and have long wished that mic selections would be more carefully documented for commercial releases.

Here's what one of your links had to say --

Nunn tried many different microphones. In the early days, he used condenser microphones from Stephens Tru-Sonic, Neumanns from Germany, and others. He tried modifying commercially-built equipment. He was never entirely satisfied with the results and finally, around 1960, he built his own condenser microphones. They had small diaphragms to keep the system resonant frequency well above the range of audibility. The vibrating diaphragm frequency-modulated an RF signal, with the cables of a fixed length as part of an RF tuned circuit. After Nunn's death they were sold.

In addition to the DPA and various B&K (and other instrumentation mics) out there, Josephson makes the Series 6 microphone body that uses the 1/2" capsules and is 48V phantom powered.  It would be interesting to make some recordings with the various sorts of microphones using these capsules to see if there are any notable differences.

Mark Stahlman
New York City

3

Tape Tech / Re: Dolby 361 Schematics anyone?

« on: February 09, 2010, 04:40:06 PM »

Charles:

I have the Model 361 Instruction Manual -- which has Section 9 (Interface circuit description) and Section 11 (Interface servicing) -- with various drawings but nothing that resembles a real schematic for the chassis.

Lots of I/O signal paths, however.  Glad to send you the PDF if you'd like.

Mark Stahlman
New York City

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Reel to Reel Tape Machines / Re: The R2R machine used by the Fine's for your collection

« on: February 09, 2010, 10:51:15 AM »

Charles:

Interesting about the RF-based mics -- might you have a schematic (even hand-drawn)?  The MKH series schemos are online (or I have them) if you'd like to compare.  I wonder what the patent story is on that design principle?

Bruel & Kjaer do not build RF-based mics.  The instrumentation capsules are (mostly) high-voltage polarization (i.e. 200V) followed by impedance-matching preamps.  There is an RF-based carrier system but based on the fact that I've never seen a complete one come up on eBay, that was a highly unusual option meant for long-distances.

A couple years ago I got a pair of RF-based mics and some 1/8" B&K capsules as well as some MKH 110/1 mics in trade for a Nagra IVS from a radio journalist in Marseilles.  These were hand-stamped "Melodium Made in France" on the case and actually use 200V capsules.  Melodium didn't make them (as were long out of business in 1976 when these components were dated) and, if French, they wouldn't be stamped in English.

I've walked around AES with them and tried to get B&K, G.R.A.S. and Aco-Pacific to help me to ID them and no one seems to have a clear idea where they came from.  An East German Cold War "scam" to get some hard currency?

Maybe you can help me to get them working!

Mark Stahlman
New York City

5

Reel to Reel Tape Machines / Re: Otari MTR-20 - worth keeping? - kind of urgent situation

« on: February 09, 2010, 10:17:17 AM »

Hello:

You never told us what the track configuration on your machine is -- 2T or 4T, 1/4" or 1/2" -- which will have a lot to do with what the machine is worth.  Did you sell it or keep it?

This is a site that is focuses on 1/4" 2T recordings and the MTR-20 would be good for that purpose, if you aren't worried about getting spare parts for a machine that is very rare. 

There is what appears to be a 1/2" 2T machine from Tennessee on eBay now with a starting price of $4500 + freight.   That sort of setup is for mastering mixdowns and not for replaying TP tapes.  As I recall, 1/2" 2T Otari headblocks often go for $1000+ (depending on test results, etc.) so this guy is unlikely to get his starting price.

If you sell the MTR-20 you are NOT likely to find another one to replace it, since maybe only 200+ were ever made.  However, there are many other decks out there which will probably meet your needs.  Btw, I own a set of spare parts and 3x headblocks for mine.

Mark Stahlman
New York City

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Reel to Reel Tape Machines / Re: Otari MTR-20 - worth keeping? - kind of urgent situation

« on: February 01, 2010, 03:42:03 PM »

Hello:

Yes your machine is worth saving and as suggested you should try to find it a temporary home while you sort this out.

This is one of the last of the Otari studio mastering decks and is capable of 2T, CTTC and 4T setups.  It has a very nice transport and will support up to 14" reels.

There weren't too many of these made (200+ ??) and it's not as famous as the Studer A820/etc that it was meant to compete with so you aren't going to get "star quality" prices but you should get enough to make it worth your while.

Depending on the head condition (and shipping costs), you could get at least $500-1000 for it.  Properly maintained (and with the right playback electronics) it would be a fine machine for TP tape listening.

Mark Stahlman
New York City

7

Reel to Reel Tape Machines / Re: Nagra TI Instrumentation Recorder

« on: January 26, 2010, 03:05:32 PM »

Max:

How can I help -- how good are you on the test bench?

Yes, I do have schematics. <g>

Mark Stahlman
New York City

P.S. We should take this private unless it's instructive for other list members.

8

Reel to Reel Tape Machines / Re: Most Ideal Stellavox model for TP tape play?

« on: January 19, 2010, 01:25:19 PM »

Giorgio:

Fancy meeting you here! <g>

Of course the headblocks/tensionometers are the really valuable part of all this, so with 16mm-only units being offered for $5000+, this does seem like the right price range for what will surely be a very unique buyer.

It was the need for more than two tracks in a portable machine that drove me away from analog recording.  I'm very interested in 3D sound and you need 4 tracks to record the space ambisonically + plus 2 more (plus?) for the "main act."  Therefore the Sound Devices 788T.

Since Kostas has long been distributing his recordings as 48kHz tracks on DVDs, I have been bugging him for years to take advantage of the medium -- which easily accommodates 6x tracks.

With the Nagra VI, he's finally got what he needs!

Mark Stahlman
New York City

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Reel to Reel Tape Machines / Re: Check out Sony studio in NYC

« on: December 30, 2009, 07:05:01 AM »

Steve:

My MTR-20 has done all that I expected of it -- excellent tape handling (from 7" to 14" reels) and I really like the ability to setup and align for many tape formulations.  I also like using the CB-120 autolocator.  This is a fully automated machine that was probably one of the last to be designed before digital took over, so it's the state-of-the-art at the end of the analog era.

It's a big-block studio machine, so the headblock is a prime candidate for substituting and the cabling should make it fairly easily for "wiring out" to external repro electronics . . . just as Paul has smartly done.

Plus -- much cheaper than an equivalent (?) Studer A820 and its a true 4-channel machine.  Minus -- much more rare so parts will be a problem and AFAIK there are no schematics floating around in case it breaks down.

Mark Stahlman
New York City

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Reel to Reel Tape Machines / Re: Check out Sony studio in NYC

« on: December 29, 2009, 01:23:27 PM »

Steve:

Sorry, I don't know of any comprehensive Otari now-and-then lists or websites.

I bought my MTR-20 from Fred Thal, the moderator of the (sometimes?) Studer list.

He is a collector of Studer and appears to be very knowledgeable.  He also apparently once worked at Otari and considered the MTR-20 to be the only Otari machine that was Studer "class."  You know how those Studer people are. <g>

Of course, the MTR-20 came too late to have any impact in the market and my guess is that only 200-or-so were ever made, which probably makes it even rarer than a Stephens.

I got a complete 1/2" 4-track machine plus the keys pieces of a 1/4" CTTC machine as spares plus the service manual -- without schematics which he said he never recieved. 

This all began when I bought a 1/2" 2-track headstack that was supposed to be for the much more common MTR-12 but it was really for the MTR-20.  Funny how those things happen.

There was one that recently sold on eBay in the LA area and its studio mastering cousin the 2-track MTR-15 shows up from time-to-time.  The MTR-15 would probably make a good TP machine, if you're looking for a bargain and aren't scared off by the brand.

Mark Stahlman
New York City

11

Reel to Reel Tape Machines / Re: Check out Sony studio in NYC

« on: December 29, 2009, 05:03:15 AM »

Folks:

I have one of the Cello 4-track Audio Suites from that auction.  John French and I bid together for one of the machines, having arranged that he would take the RTR w/ headblock and I would get the electronics w/ Cello head cabling (this one had no PSU).  Another fellow got 2x complete A820 units as well as an A800, while the last one went to another guy.

I'm planning to interface my unit to my Otari MTR-20 for 4-channel playback one of these days.  I have substituted 2x HP lab power supplies to replace the +/- 30VDC from the Cello PSU.  Yes, I'm still looking for a source of three-channel stereo masters. <g>

There was also a fairly complete stereo Audio Suite + PSU that sold at that classic auction for $5K (or so) and then was resold by a UK dealer for around $8K, as I recall.

Sony was a big customer for Cello back in the day.  When Sony started selling "surplus" on eBay, I bought a variety of items and woundup with a three-chassis stereo mastering Audio Suite, which had been replaced by a 7.1 Massenburg setup.  I sold that unit to a collector and mu guess is that it's sitting in his warehouse.

Mark Stahlman
New York City

12

Reel to Reel Tape Machines / Re: Most Ideal Stellavox model for TP tape play?

« on: December 29, 2009, 04:38:06 AM »

Ki:

The Stellavox equivalent of the Nagra T-Audio is the TD9.  It was a studio machine that was mainly used for playback of field recordings.  In the TA case, these were often time-coded movie dialogue from an STC-IV.  The TD9 had the unusual capability of mounting 16mm-35mm film transfer heads as well as 1/2" and 1" mag-tape.  The head blocks and tensionometers were replaceable modules and it could accomodate up to 4 channels of audio.

These machines are quite rare and only a few of them seem to have made it to the US.  The two that I have located have 16mm heads.  Your best bet for information is the Rolland Schellin book "Stellavox: Voice of the Stars" (which both Charles and I contributed to) and the current "factory," which is JP Gurtner -- [email protected] at www.audioprojpg.com.

Mark Stahlman
New York City

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Reel to Reel Tape Machines / Re: Let dream about designing a new machine!

« on: September 09, 2009, 12:55:46 PM »

Steve:

Ha!  Yes, I have probably been among the most "promiscuous" of those buying (and selling) tape decks in this free-wheeling eBay era. <g>

No Studer.  No Telefunken.  No MCI.  Most other pros going back to Maggies (i.e. not consumer).  I donated my Racal's to Richard.  He knows what to do with them.  Transfer tapes.

Instrumentation electronics aren't meant for audio -- which is why most audio people don't even know they exist.

However, instrumentation mechanicals might make an interesting platform for a "new machine."  New electronics and heads, I would suspect.

It would be interesting if 50-100 of these now-useless Nagra TI-8's could be rounded up . . . presuming they aren't already in landfill.

Mark Stahlman
New York City

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Reel to Reel Tape Machines / Re: Let dream about designing a new machine!

« on: September 09, 2009, 05:38:10 AM »

Folks:

The Nagra TA was not originally meant to be an audio tape recorder.  Which is why it is "portable" (i.e can be DC-powered?)

It began life as the TI -- a four-channel 1/4" instrumentation deck with speeds from 15/16 to 60 ips.  Which is why is has double capstans.

Nagra had successfully taken the market for instrumentation recorders away from Bruel & Kjaer (and others) with the adaptation of the IV-SJ.  That recorder had preamps that directly connected to 200V instrumentation microphones (yes, with an internal step-up power supply) and step attenuators.  The competition was the B&K 7005/6/7, which also had four channel pluggins.

Instrumentation tape recorders are little known by audiophiles.  They typically cost $20K+, had multilple channels and cost-no-object engineering -- generally well above audio gear, because they were paid for by tax (or industrial) and not broadcast or studio dollars.  Since they are no longer used, they are now cheap on eBay.  I have owned B&K, HP, Racal, Stellavox and Nagra instrumentation decks.

Inputs were interchangable between FM recording (i.e. no AM-bias and recording to 0 Hz) and direct recording (i.e. capstan-speed scaled AM-bias and upper limits in the 100 KHz range).  They use different magnetic tape and since they didn't use audio pre-emphasis, the 45dB signal-to-noise ratio is generally unacceptable for audio purposes. 

Except for the Nagra IV-SJ which does use EQ.  It's sometimes used for audio recording, since it can use the cheaper 200V B&K mics (i.e. less than the DPA 130V polarization derivatives.)

Somewhere around 900 Nagra TI's were manufactured but as a 4-channel device it was past it's time as instrumentation recorders were moving to DAT and 8/16 channels.  Around 300 of these TI's were OEM'ed by a German Bell & Howell subsidiary and re-enginneering as 8-channel 1/4" machines - the TI-8.

The Nagra T-Instrumentation failed and thus was re-born as the Nagra T-Audio -- to recover the engineering costs, or so I was told.

I owned one of these TI-8's which was going to be the original platform for a tube-based Frankencorder.  Beautiful machine.

Mark Stahlman
New York City

15

Reel to Reel Tape Machines / Re: Let dream about designing a new machine!

« on: September 08, 2009, 11:34:38 AM »

Charles:

Good idea -- SMALL.  That was what John Stephens was aiming for before he died.  I great portable (i.e. under 40 pounds) 1/2" transport.

Few decent "stock" playback electronics?  Given that you have so much experience with them, do you include the Stellavox SPC/SOC on the decent side of the equation?

Have you heard Kostas Mexatas' updated version plugins?  Any significant improvement -- to your ear?

The Stellavox was (arguably) one of the few portable tape machines made for "musical" reproduction.  Based on usage, it seems plausible that the Nagra IV was designed for dialogue (i.e. voice).  The Nagra TA seems to have been most often used for studio playback of IV-STC tapes and promotes its low-level IM distortion in the sales literature, achieved with lots of op-amps.

Is there something to be learned from the Cello electronics for this purpose?  Class-A discrete electronics?

Mark Stahlman
New York City