Tape Project Forum
Tape Machines => Reel to Reel Tape Machines => Topic started by: ironbut on September 04, 2009, 02:32:03 PM
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I know this subject has come up before here and on other reel to reel forums but after looking at the membership numbers here I'm beginning to get that ole' itch again.
Disclaimer time,..
This is something that's entirely out of thin air and there's nothing that I've heard or seen that leads me to believe there is a machine being devised. But maybe if we all hold hands and click our heels together?
So, I'd like the members to say what they'd like to see in a machine. What features and spec's are a must and what should just be options.
To start out, I think that there's no question that this would be a hand built machine so just having a nice heavy deck plate milled, motors and motor control units (of whatever design), an exchangeable headblock (or do we want that?) and a system for moving the tape (or heads) into contact we're probably already talking in the $10k neighborhood. For such a machine to be worth this kind of price, it has to be capable of a least competing with the likes of an A820 or ATR102.
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For such a machine to be worth this kind of price, it has to be capable of a least competing with the likes of an A820 or ATR102.
Precisely.
At one time there was a fear that we might run out of good ATR's or 820's. That doesn't seem to be the case anymore. So the machine would have to offer something that the ATR or 820 doesn't offer too, or what's the point.
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Steve:
Paul is right. There appear to be enough of the last generation of studio mastering decks out there -- Ampex ATR-102/4, Studer A820, Otari MTR-20/15, Stellavox TD-9, Nagra T-Audio, Sony APR-5003 -- at $1000-$5000 prices with spare parts and technicians available, to satisfy the 100's of people who are interested.
What was missing in these machines that we should add today? Then, would it make sense to start with one-or-more of these existing "platforms" and add those features?
Mark Stahlman
New York City
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Steve:
Paul is right. There appear to be enough of the last generation of studio mastering decks out there -- Ampex ATR-102/4, Studer A820, Otari MTR-20/15, Stellavox TD-9, Nagra T-Audio, Sony APR-5003 -- at $1000-$5000 prices with spare parts and technicians available, to satisfy the 100's of people who are interested.
What was missing in these machines that we should add today? Then, would it make sense to start with one-or-more of these existing "platforms" and add those features?
Mark Stahlman
New York City
That is what is being done as of now.
I think this was supposed to be more of a "what if" exercise.
But, one wish I might have along the lines of new hardware would be for Bottlehead to build a companion set of recording electronics to their playback ones.
Then, if some machinist among us would care to make a beautiful transport of some sort, all that would be left is to integrate the pieces.
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You guys are right of course. I guess I'm just hoping to stir up a little brainstorming and see what kinds of ideas other members have daydreamed about.
I have a couple of ideas about ways to move the tape a little more precisely. They may well have been tried at one point but the limits on materials and/or manufacturing tolerances may have prevented them from working at the time.
The first one is a possible way to eliminate the influence of scrap flutter at the head rather than trying to get rid of every bit of it in the tape path. The idea is to mount the heads inside of a capstan/idler. The capstan/idler would need to be large in diameter (I'm guessing 4" or so) and would control the tape speed as it rotated past the fixed heads inside. I'm guessing that the tape would need to lay on a couple of inches of the outside rim of this petri dish shaped idler. A couple of guides before and after would wrap the tape on the idler. The outside rim would have a path of highly permeable material that would need to be extremely thin to maximize flux density transfer to the head inside. Of course, any wow and flutter as well as rumble from the capstan/idler would need to be vanishingly low so maybe a magnetic/air bearing combination could be employed.
All of this won't be practical unless a head could be devised which is sensitive enough to read everything that's imprinted on the tape from what would be a relatively long distance compared to a head which is in intimate contact with the tape surface.
I would guess that if this has been attempted before that this was a major stumbling block. The reason I think this could work today is the advances in the read/write heads on hard drives. I haven't really looked into this very far but I do know that some no longer contact the disk surface at all now. And it would seem that the "heads inside the idler" would remove the need for the heads to be in the least bit robust.
Idea 2 this one's somewhat linked to the one above
This is an idea for playback only. It's based so heavily on Jamie Howarth's Plangent Process that it could well be an infringement on his patent. For those who don't know, here's a link;
http://www.plangentprocesses.com/
The Plangent Process is a speed correction hardware/software package for digital transfers of magnetic tape. It employs the imprinted recording bias as a time constant. Fantastic idea IMHO! It's particularly useful when old tapes which are damaged or were recorded at speeds that either varied or were outside of the normal standards (ie. Kind of Blue). Corrections in speed are done in the digital domain.
So, if we're just talking about playback here, why not use it instead of a crystal oscillator to control tape speed variations? The process does require a special head to read the bias frequency. This would introduce more scrap flutter in a normal arrangement since this head needs to be before and close to the playback head (the distance and time delay is compensated digitally in the Plangent Process). But, if this head were located inside of the capstan/idler this wouldn't present itself as a problem. It could even serve as the guide that precedes the capstan/idler.
Well, those are my two whacky ideas for today. Please feel free to hack away at them.
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Since reel to reel machines exist and one could be retro engineered in order to produce a new one (if such a demand arose) a newly built one off reel to reel while an elegant concept I don't see it as having a practical use.
However this does not rule out the possibility of an entirely new style tape recording device. Along with my recent reel to reel excursions I've also investigated recording into a hi fi stereo VCR and with excellent results. Results that perhaps exceed my TEAC A 2300 SD. I'd like to see a purely audio recording device based on the VHS format but with perhaps 6-8 tracks. Such a machine with on board effects like a modern digital work station and a USB interface for communication with digital sources would be an interesting device.
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Steve,
Thanks for the discussion topic. Interesting as a thought piece, but unless you have a really good friend who is a master mechanic I'd forget about ever seeing a new deck appear.
Also; nowhere do I see what to me is one of my most important considerations - size! I want to see the "ideal" deck in a case about the size of a shoebox, LOL. I don't have or want to take up the space a studio deck requires - ever tried to move/pick up an A80! Like to have my "decks" relatively portable, for location recordings and demos at shows/meetings.
If you really want to I think you could put together an "ideal" deck from currently available machines. Let's look at very good "portable" transport candidates; Nagra S and T (much better), Lyrec Frieda (can become noisy), Stellavox Sp (large reel takeup a problem). Many studio transports seem to handle tape just fine. Apparently the Studer A8XX series are a VERY good machines. Nothing wrong with the Technics 1500 series that I can determine.
Then there is the electronics issue. As I've mentioned before, heads sound (vastly) different- and I only talking about playback - never tried "listening" to record heads. Have heard very few decent stock playback electronics. Suggest that this is the area where the most sonic improvements may be achieved.
Charles
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I think we can all agree that this thread is more of a "think piece" as has already been mentioned. My hopes for it would be for something practical to come out of it at some point. Furthermore, I think that discussion of the challenges of magnetic tape recording and playback will help myself and others to better understand the breed in general.
I agree with you regarding machine size and weight. Although you'd be hard pressed to find a machine that's much "cooler looking" than an A80, you could probably fit 2 ATR100 or Nagra T's into the same footprint. In fact, after seeing Doc's beautiful integration of his Repro and Nagra T in person, it's really between that and an ATR for me (this month at least!).
I'm really interested in hearing about your findings regarding heads. As far as I know, there's no limit other than physical size on the playback heads that can be used on any given machine. Keep us posted on that one.
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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
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an A80, you could probably fit 2 ATR100 or Nagra T's into the same footprint.
More like 2-1/2 Nagras in an A80 or maybe 1-1/3 ATRs. The Nagra T is much smaller and MUCH lighter than an ATR 102, probably 40 lbs. vs. 120 lbs. For the absolute best performance I'd rather have an ATR. But to fit in my listening room I'd rather have a Nagra. But probably the cleanest and neatest looking of the three in a larger home listening room is the A80 - or A820. I hope to compare my Nagra/Repro with Shunyata's Spitz ATR/Repro soon.
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probably the cleanest and neatest looking of the three in a larger home listening room is the A80 - or A820
Wait 'till you see my Spitz ATR in a vertical rack dressed in Tzalam!
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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
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Yikes!
I'm beginning to wonder what machines you haven't had? I looked at instrumentation recorders for a while and emailed Richard Hess a bit regarding his Racal Store. He convinced me that it was an audio dead end but I still wouldn't mind looking over a few to see what made them tick (just figuratively).
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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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Speaking of instrumentation transports, if anyone ever comes across an Ampex FR-1400 transport looking for a home, I would be interested. I know they are gigantic, but I have a particular app in mind that it might work well for.
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From a quick google, I stumbled across this guy. He's in Oakland but you'd have to check to see if the Ampex is there.
http://www.artichokepro.com/pages/stuff.html
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Thanks, talked to him a while ago and it is long since gone. Couple years ago I wavered over one on ebay for $99 that was in the South Bay. Lucky you, I prolly woulda asked you to pick it up...two 6' tall racks...
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He he,.. a couple of years ago I would've had use of a flat bed, a fork lift and a warehouse with nothing but a couple of wooden boats and a spray booth. For a six pack I probably could've gotten away without getting my fingernails dirty (or bloody).
One of those boats is for sale (or was). Check it out. My ex-boss and wife were given an award in Italy for this restoration.
http://www.portcarlingboats.com/pmehus/pmehus.htm
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Since reel to reel machines exist and one could be retro engineered in order to produce a new one (if such a demand arose) a newly built one off reel to reel while an elegant concept I don't see it as having a practical use.
However this does not rule out the possibility of an entirely new style tape recording device. Along with my recent reel to reel excursions I've also investigated recording into a hi fi stereo VCR and with excellent results. Results that perhaps exceed my TEAC A 2300 SD. I'd like to see a purely audio recording device based on the VHS format but with perhaps 6-8 tracks. Such a machine with on board effects like a modern digital work station and a USB interface for communication with digital sources would be an interesting device.
Keep in mind however that VHS HiFi is not a stationary recording medium. The audio is FM modulated to 1.3mhz (left) and 1.7mhz (right) and applied to the video heads. You aren't going to record 1.3 or 1.7mhz with stationary heads running at 0.5ips such as in VHS EP mode. Also FM recording is not the holy grail. As we know the signal quality is a product of the deviation. In VHS HiFi it is rather narrrow hence they use a DBX type compander to get around that. You have the FM video carrier at roughly 3mhz and the AM chroma at 629khz there as well so intermodulation is a serious issue. But as the frequency responce is still very flat across the audio band being recorded andf played back the companding works much better than with straight analog recording but still pumps. Then we have the achiles heel of FM video recording. The head switching. The tape is only wrapped half way around the head drum so they switch between two heads to maintain continous tape contact. this produces a strong 60hz DC offset in the recovered signal due to tension differences in the tape. So to minimize that there is usally a 60hz notch filter employes.
No, VHS HiFi really isn't HiFi by our standards here.
You know they did come up with a solution to all these issues - it's called RDAT!
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Since reel to reel machines exist and one could be retro engineered in order to produce a new one (if such a demand arose) a newly built one off reel to reel while an elegant concept I don't see it as having a practical use.
However this does not rule out the possibility of an entirely new style tape recording device. Along with my recent reel to reel excursions I've also investigated recording into a hi fi stereo VCR and with excellent results. Results that perhaps exceed my TEAC A 2300 SD. I'd like to see a purely audio recording device based on the VHS format but with perhaps 6-8 tracks. Such a machine with on board effects like a modern digital work station and a USB interface for communication with digital sources would be an interesting device.
Keep in mind however that VHS HiFi is not a stationary recording medium. The audio is FM modulated to 1.3mhz (left) and 1.7mhz (right) and applied to the video heads. You aren't going to record 1.3 or 1.7mhz with stationary heads running at 0.5ips such as in VHS EP mode. Also FM recording is not the holy grail. As we know the signal quality is a product of the deviation. In VHS HiFi it is rather narrrow hence they use a DBX type compander to get around that. You have the FM video carrier at roughly 3mhz and the AM chroma at 629khz there as well so intermodulation is a serious issue. But as the frequency responce is still very flat across the audio band being recorded andf played back the companding works much better than with straight analog recording but still pumps. Then we have the achiles heel of FM video recording. The head switching. The tape is only wrapped half way around the head drum so they switch between two heads to maintain continous tape contact. this produces a strong 60hz DC offset in the recovered signal due to tension differences in the tape. So to minimize that there is usally a 60hz notch filter employes.
No, VHS HiFi really isn't HiFi by our standards here.
You know they did come up with a solution to all these issues - it's called RDAT!
When I refer to a VHS format I'm not saying that the entire audio signal chain be that of VHS format. I'm thinking more on the lines of the tape cartridge, rotating head and transport layout. The tape speed could run at a faster than VHS speed perhaps double giving 1 hour tape time per cartridge. As it would not be concerned with a video signal all of the engineering could be devoted to audio only. Considering that Hi Fi 1/8" cassettes are fairly capable devices the device I envision should be able to exceed that quite easily.
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Even though I meant it to deal with cassette tape deck, there are some points of view about open reel decks in this thread I started up on another community some time ago.
Please have a look:
http://www.tapeheads.net/showthread.php?t=1407
Just for fun.
"dolph"
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When I refer to a VHS format I'm not saying that the entire audio signal chain be that of VHS format. I'm thinking more on the lines of the tape cartridge, rotating head and transport layout. The tape speed could run at a faster than VHS speed perhaps double giving 1 hour tape time per cartridge. As it would not be concerned with a video signal all of the engineering could be devoted to audio only. Considering that Hi Fi 1/8" cassettes are fairly capable devices the device I envision should be able to exceed that quite easily.
If you keep the rotating heads you have two choices: FM analog or digital technology. The digital is superior in many ways one of which is the data can be buffered to get around the head switching problem.
Again they basically have made a format on this principal, RDAT. The Sony PCM800 is a good example. Tascam made a compatable unit as well.
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Well, as long as we a putting forth a wish list for a new machine:
1. Great tape handling.....but easy/fast to thread. Maybe I need a whole bunch more practice, but I find the RS15XX series to be not fun to thread. It is an effort. If I am a little tired or have had an adult beverage, I tend to avoid my Technics RS1520. I don't have that problem with my Revox A77 which I use for 4 track tapes.
2. At least two speeds - 15 ips and 7.5 ips. And with a 4 track playback head.
3. Great electonics - I am OK with tubes. It would be great to have a tube wear indicator, like VTL has on one of its amps.
4. On board Dolby B circuit for playback of my 7.5 ips Dolby encoded tapes.
5. Switchable IEC/NAB equalization.
6. Of course, 2 track playback head optimized for Tape Project tapes.
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When I refer to a VHS format I'm not saying that the entire audio signal chain be that of VHS format. I'm thinking more on the lines of the tape cartridge, rotating head and transport layout. The tape speed could run at a faster than VHS speed perhaps double giving 1 hour tape time per cartridge. As it would not be concerned with a video signal all of the engineering could be devoted to audio only. Considering that Hi Fi 1/8" cassettes are fairly capable devices the device I envision should be able to exceed that quite easily.
If you keep the rotating heads you have two choices: FM analog or digital technology. The digital is superior in many ways one of which is the data can be buffered to get around the head switching problem.
Again they basically have made a format on this principal, RDAT. The Sony PCM800 is a good example. Tascam made a compatable unit as well.
It was another one that me suggesting anything digital in the thread I linked to.
I want to keep it stricktly analog.
"dolph"
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It was another one that me suggesting anything digital in the thread I linked to.
I want to keep it stricktly analog.
"dolph"
You mean a 1/2 inch cassette analog stationary head format? Just keep in mind there is not much tape length in a VHS cassettte for high linear tape speeds.
My we interest you in an El_Cassette? Remember that format?
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It was another one that me suggesting anything digital in the thread I linked to.
I want to keep it stricktly analog.
"dolph"
You mean a 1/2 inch cassette analog stationary head format? Just keep in mind there is not much tape length in a VHS cassettte for high linear tape speeds.
My we interest you in an El_Cassette? Remember that format?
I remember EL-Cassette.
And that's Not what I mean either.
Now; If you reread the thread I linked to and remember my nickname is the same as here, then I'm sure you will get an idea about what I mean.
"dolph"
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Use of a 1/2' VHS cassette has many issues. Not much tape so no high speed. Wrong type of tape for best analog audio performance and you cant use narrower tracks and turn the tape over like a normal audio cassette. You could double the length with some sort of special auto reverse transport but it would still be very short at a speed that would give any kind of quality with analog technology. And as was pointed out you can't use normal analog technology with spinning heads. Closest would be something like VHS HiFi FM system.
My vote for a new open reel design would be something like a cross between an updated old Ampex 350 series transport and the famous little Sony 770 that used clever electromechanical technology to provide more or less constant tape tension. Something clever and simple without a lot of microprocessor controlled complex circuitry and sensors, yet providing excellent tape handling and precise speed and tension control. More Nagra than Technics if you get my drift. And as I posted earlier, tube record electronics from Bottlehead to match their playback ones, designed for state of the art heads. All in some sort of portable case please. Preferably not much bigger than say a Revox A77.
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So, I'd like the members to say what they'd like to see in a machine. What features and spec's are a must and what should just be options.
To start out, I think that there's no question that this would be a hand built machine so just having a nice heavy deck plate milled, motors and motor control units (of whatever design), an exchangeable headblock (or do we want that?) and a system for moving the tape (or heads) into contact we're probably already talking in the $10k neighborhood. For such a machine to be worth this kind of price, it has to be capable of a least competing with the likes of an A820 or ATR102.
I was speculating about this not long ago on another list. For it to be worthwhile, I think it needs to offer something the Studers and ATRs don't offer: portability.
I'd start from the latest Stephens design and then try to make it even smaller and more reliable. A 2" 16-track that weighs 50 pounds in two portable racks with a high quality companion rack console would be very handy for folks like me who have to move gear to record in better sounding places or to where certain instruments are or to where music takes place. I'd also prefer automation for setup, i.e. a machine with built in diagnostics and automated calibration with settings for favorite tape formulations and level preferences. Robust, built in sync capability, too.
Cheers,
Otto