Messages

1

Reel to Reel Tape Machines / Re: Studer A80 - horizontal or vertical mount?

« on: April 10, 2010, 08:15:50 AM »

And the wow and flutter performance is better in horizontal than vertical orientation. This is true of most tape machines.

Yeah, who needs gravity accentuating the wobbles in the rotating transport parts?

Cheers,

Otto

2

Reel to Reel Tape Machines / Re: How do you measure tape tension

« on: February 19, 2010, 02:25:38 PM »

It seems like the 3M designers were acutely aware of the factors that tape tension and the tape path contribute to. I would imagine that the calibration procedures for those machines are far more comprehensive and exact than just using any tension device would be.

Yes, 3M did pay attention to this.  The Isoloop is a capstan-driven transport, so setting the incoming and outgoing capstan/pinch roller pressures pretty much gets things working as they should.  The reel motor torque is just there to keep the tape from going slack.  The tape tension is applied to the tape within the loop (by the differential radii of the tape passing by the two sides of the capstan) and it is slightly stretched, so it actually moves faster than the tape outside the loop. 

It's been my observation that the 2" diameter capstan seems to handle differences in tape thickness more readily than standard style transports with small capstans.  Certainly, the adjustment is far easier to do on the 3M than adjusting capstan/pinch roller pressure on the Otari, since you just need to pull off the top transport cover and you can easily do everything from the top with a single screwdriver, versus having to pull the bottom cover, swinging out the transport card and reaching way inside to try to adjust the two nuts that set the pressure on the Otari (and then having to right the machine to test the thing after each tweak).

Cheers,

Otto

3

Reel to Reel Tape Machines / Re: How do you measure tape tension

« on: February 19, 2010, 11:07:34 AM »

Hi Dave,

I use a device called a Tentelometer. You can find them on eBay for pretty cheap but it's kinda hit and miss as far as accuracy goes.
There are many different models and I prefer the ones with the rolling probes (you'll see what I mean when you visit their site).
Also, you need to get one that's made for the right tape width and tension range. When you get it, you should calibrate it to the range you're going to be measuring. There's instructions for this on their site also. I use some cheap weights I got from Edmund Scientific for this.

http://www.tentel.com/Default.htm

I'm pretty sure that this is covered in the " Beginners Guide" located in a sticky above the General forum.

Interesting! I've never used a tentelometer, nor measured tape tension per se.  My tape machines (3M and Otari)don't have specs for tape tension, nor do the manuals include a tape tension measurement as part of the transport alignment process nor do they spec a tentelometer as part of the maintenance kit.  I'm not really sure what I would do with the data.

I do use spring scales in the spec'ed ranges  for reel motor torque and for capstan/pnch roller pressure adjustment on the Otari.  On the 3M machines, the capstan/pinch roller pressures are set by a cailbrated procedure, not by pressure measurement and corresponding adjustment.   

Any idea how long the tentelometer has been around?  It may not have been an option back in the early '60s, when 3M designed the Isoloop transport for their audio recorders.

Cheers,

Otto

4

Tape Tech / Re: Oscilloscope for RTR Alignment.

« on: January 08, 2010, 04:55:00 PM »

I remembered correctly.  Dale says he will no longer sell the direct-drive servo kits for the 3M transport because he doesn't want to have to support them.  Too bad.

Cheers,

Otto

That's a beautiful M23 Otto! Fantastic work there.

Perhaps you could give us a little detail regarding the servo upgrade you mentioned.

I seem to remember that Dale was working on a way to do away with the stepped capstan also.

I just sent him an email to ask if he still has the kits and if he will sell them.

Here's the link:

http://www.manquen.net/audio/index.php?page=4

Cheers,

Otto

5

Tape Tech / Re: Oscilloscope for RTR Alignment.

« on: January 08, 2010, 03:05:24 PM »

That's a beautiful M23 Otto! Fantastic work there.

Perhaps you could give us a little detail regarding the servo upgrade you mentioned.

I seem to remember that Dale was working on a way to do away with the stepped capstan also.

I just sent him an email to ask if he still has the kits and if he will sell them.

Here's the link:

http://www.manquen.net/audio/index.php?page=4

Cheers,

Otto

6

Tape Tech / Re: Oscilloscope for RTR Alignment.

« on: January 08, 2010, 09:02:31 AM »

Yep, of all the machines out there, I'd love to get my hands on a Stephens. I believe that John Stephens started out modifying 3M M23's until the parent company stopped selling them to him (I wonder why? yuk yuk). His machines are still considered by many to have been the best sounding of any multi track although I believe he produced a 1/2" 2 track.

For any of those who've never heard of them, here's a link to a Stephens brochure;

http://www.dvq.com/hifi/images/stephens.pdf

I'm working on picking up a certain Stephens 2" 16-track machine some time this year.  We've agreed on a price, but the seller is in no hurry, which is just as well, since it seems to be taking me a long time to get the funds together.  The most compelling feature for me is actually the portability of the machine.  The guts (transport/meter panel/PSU) weigh a total of about 65 pounds and work nicely in two portable cases.

Cheers,

Otto

7

General Discussion / Re: Building a Music Room

« on: January 01, 2010, 10:07:22 PM »

I am toying with the idea of adding a music room on to my house. It will be for 2 channel only SET amp power and 110db efficent horns without any subs. With the speakers in the conners what are considered to be the best dimensions for such a room? Any advice or ideas will be appreciated!!!

Jay

FWIW:

1) Generally, it is not usually a good practice to have speakers in the corner. That tends to maximize the coupling of the bass drivers to vertical modes and horizontal modes in both directions and doesn't make for the best distribution of bass in the listening region.  Many mastering folk just use two subs or two full-range speakers placed symmetrically left and right but spaced from the floor, side walls and back walls.  If you want to go that far, there is also research by a fellow at Harman who works with Pascal Sigen, a thoughtful fellow who works now with A Blue Sky monitors, indicating that the best bass response comes from a carefully arranged array of mono subwoofers.  More can theoretically be better, but four mono subs on the floor, one at the mid-point of the floor edge along each wall is about as good as you can do. 

2) Probably the best advice regarding room dimensions is: as large as possible, especially the ceiling height and use one of the cited sets of ratios to space the room modes as well as may be.

3) Regardless of dimensions, the quality of sound is mostly dependent upon proper installation of bass trapping to tame the room modes along with broadband absorbers to kill off first-order reflections and proper diffusers in the rear to create a sense of spaciousness.  You want a minimum of 20 milliseconds after the direct sound before the first reflected sound hits your ears, which is why you want larger dimensions and absorption of first-order reflections (ceiling, back wall, side walls, floor).  The bass traps help shorten the relaxation time of the room modes.

4) One simple example of a system that produces a high quality listening space is the ASC Attack Wall, which is basically a simple, portable system to produce a quality, repeatable mixdown listening space for audio production.  I have the pleasure of using such a system in my studio to mix and monitor playback of my studio recordings and it is really a wonderful thing.  The Studio Traps used to make up the Attack Wall aren't cheap, but apparently there are thousands of audiophiles around the planet content to spend far more on esoteric electronics (and high quality source material, such as the TP provides) without first ensuring they have a listening space that meets the specs we know are required for quality audio.  That's a shame! 

Cheers,

Otto

8

Reel to Reel Tape Machines / Re: Interesting machines from the past

« on: December 31, 2009, 09:10:21 PM »

Wow,.. that's gorgeous Otto!

Thanks for sharing this and all your other posts lately.

Steve:

You're welcome.  I'm new to this forum, though I've known of it for a little bit.  I started recording my music back in the early 80s when just about everything was done on tape and I'm just too stubborn to quit.  I figured I'd just dive right in.  I'm not much for lurking, unfortunately.  :)

Cheers,

Otto

9

Reel to Reel Tape Machines / Re: Interesting machines from the past

« on: December 31, 2009, 03:52:03 PM »

I would love pictures and descriptions here of interesting machines we now own or have owned. Also the characteristics that you find endearing, quirky etc.

This is my 3M M-23 1/4" machine that I finally got up and going this summer.  It took many years for me to get around to putting it all together.  Once I sold my M-79 2-track, the M-23 restoration became more urgent.

It has a rack mount transport that I suspect came from a film sync machine and two electronics channels I got from JRF's M-23 machine, all housed in a little console I put together.  The transport has a pretty low serial number (248, IIRC) so it's probably pretty close to the start of production in 1965.

http://i203.photobucket.com/albums/aa115/ofajen/IMG_8196.jpg

Aside from the huge open sound at 15 ips, I love the big 4.5" Simpson VU meters and the shiny chrome parts around the tape path.  I think the M-23s are prettier than the M-79s.  It's also got the old rim drive with a rubber tire around a 7" flywheel.  I just wish I could locate original M-23 style reel hubs.  Right now I'm using VIF hubs, so I had to steal spindles from an M-79 and install them in the reel tables.

Cheers,

Otto

10

Tape Tech / Re: Oscilloscope for RTR Alignment.

« on: December 31, 2009, 01:20:49 PM »

Keith Johnson first turned me on to the capstan refinishing thing. There was a shop in the Bay Area that resurfaced the capstan motors for the Ampex AG350's. It was some sort of bead blast finish. Rule 1 on AG350s, use the Bodine motors. The Ashland motors had design problems that limited their performance. Something about fields or heat, I don't remember what.

Keith also didn't like the stepped capstan. When I built up a 3M M23 for Reference Recordings (25 years ago now) he insisted that the pinch rollers be replaced with flat ones to defeat the differential drive. I'm not going to argue even though I'm not convinced. I would love to build a Steven's clone and ditch the pinch rollers completely. Or a machine like this: http://www.labguysworld.com/ChesterNewell_2.htm with no loop. But I have a real world to deal with.

If I get the 3M running well I'll invest in Manquen's servo upgrade for the drive.

You might get a kick out of this.  This is my M-23 that I finally got up and going this summer.  A rack mount transport that I suspect came from a film sync machine and two electronics channels I got from JRF's machine, all housed in a little console I put together.  Once I sold my M-79 2-track, the M-23 restoration became more urgent.

http://i203.photobucket.com/albums/aa115/ofajen/IMG_8196.jpg

BTW, will Dale actually sell you the servo upgrade for the M-23 drive?  He's helped me a ton over the years in keeping my other 3Ms going and in getting this M-23 together, but when I asked about the servo upgrade, he said he'd got most of them back (mainly from the Rochester School of Music) and didn't want to sell any more because he didn't want to be responsible for supporting them.

Cheers,

Otto

11

Reel to Reel Tape Machines / Re: Stephens Tape Decks

« on: December 31, 2009, 12:22:51 PM »

Folks:

Probably the most legendary of the rare decks out there, they are also quite difficult/expensive to repair since they are based on unique potted plugins -- which are have not gone back into production and, after John Stephens death, may never again be available.  So existing machines are now being consumed as donors.

Mark:

Next time I talk to Brian Roth, I'll see if there are other machines he's aware of.  I think Brian mentioned recently that the folks in Calgary who are big into the Stephens machines are now making more of the plug-in modules.  That would be good news, eh?

Cheers,

Otto

12

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

« on: December 31, 2009, 12:14:37 PM »

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

13

Reel to Reel Tape Machines / Re: Lyrec TR-55

« on: December 31, 2009, 12:04:04 PM »

I've wanted one of these since I first became aware of them last year. I doubt if there is even one or two in the US. Any group members spot one or have used one? Harold and I both use the Frida decks on a daily basis. I suspect the TR-55 would be better for studio use, as the Fridas were really meant for field recording and are somewhat finicky and lightweight.

Rich Brown

I recall that Mitch Easter used to have two of them.  I emailed him last night to see if they were still around.  One got fixed up a few years ago and then he traded it for an SVT for his studio.  The spare machine disappeared in the "Otho Vortex" and resurfaced when Matt Allen found our stuff while on a job for Randy Blevins.  I got my Auditronics console back, and Mitch got back his MCI console, the M-23 I traded to him and the spare Lyrec.  He still has the spare Lyrec but it is no longer complete and all the recorders are kinda worse for having been stored in an unconditioned space for many years.  He said his impression was that the machine was top notch, but that the servo system on his older machines wasn't quite perfected (hence the need for repairs) and that later models were better in that regard.

Cheers,

Otto

14

Reel to Reel Tape Machines / Re: Transports and tape handling

« on: December 31, 2009, 11:54:46 AM »

A Stephens! I know someone who was involved in building a couple of those way back. Light portables for mobile use.
An interesting and unique optical method was used to ensure speed stability I understand.

Brian.

The earlier machines actually used 3M transports, but eventually 3M got tired of him stealing their recorder business using their own transports.  His later transports are capstanless and completely driven by servo-controlled reel motors.  You can even spool tape directly from one reel to the other.  Same basic size and layout as your basic 3M transport, but with the tiny channel electronics installed right on the front face of the transport.  No transformers on I/O which saves a lot of size, weight and cost.  Basically, the whole machine is that little transport, a power supply and a sync/meter panel. The 16-track weighs 102 pounds in a console.  The pieces only weigh about 65 pounds.

Cheers,

Otto

15

Reel to Reel Tape Machines / Re: Buying an Otari MX5050! Hooray

« on: December 31, 2009, 11:03:24 AM »

Hi there

I recently discovered a store selling two otari reel decks, a mx 5050 bII 2 and a mx 5050 mkIII 8. I'm trying to build a good recording setup for my music and tape is the only way I'm going to do it. Currently I have the mk 5050 mkIII 8 getting looked over by a service man but sadly I't doesn't come with any reel nabs and he doesn't have any tape to test the play back (although on first inspection he liked the look of the heads)... As soon as he gives me a report on its condition I will post the findings. My main reason for this thread is to ask what difference in recording would the 1/2" tape on a mkIII 8 be compared to 1/4" on a BII 2. Any type of advice I welcome..

I believe all those machines will be 15/7.5 ips, so both should be able to give flat response up to 20K and perhaps beyond at 15 ips (my mkIII is only down about 1 dB at 25K).  The BII 2 will be able to do both NAB and IEC eq, while the mkIII-8 will probably be IEC only, as that is far more common.  The mkIII-8 channel cards don't switch EQ, so you just have to pull the back/top cover and see which kind they are. 

The 2-track does have wider tracks, but in practice it is a reasonable combo for tracking and mixing, since you can reduce noise from the 8-track via track muting, gating/expansion, careful fader control or the dreaded noise reduction (ick).

Since you are wanting to do a bunch of tracks to tape and then port to PT, the 8-track would probably be more convenient, since you can track stuff in sync and then port over together to PT.  The 2-track would not be very handy for that, unless two tracks is enough.

Cheers,

Otto