Dumb Tape Questions

Discussion in 'Tape Recorders' started by Jeemy, Jul 8, 2006.

  1. Jeemy

    Jeemy Well-Known Member

    Sep 19, 2003

    Some of you may remember I bought an Otari MX5050, ASC Centretrack and Adams-Smith Zeta 3 with 2 Dolby A 361s.

    Well I cabled it into the patch bay, worked out from some pictures how to thread the tape and got it running, and I recorded a session of a singer songwriter - suffice to say I was sufficiently with the impression of the tape mix which I ran as a split from my monitor feeds to wish to continue developing.

    I have got some basic questions which I am sure a veteran using these machines could answer....please help.....:

    1) How do I fix the tape to the empty reel? I have just been thumbing it onto the reel until the next turn came round, and once it held itself down, ran it onto the reel. My plastic reel has little circular fittings which you could attach the tape to, but I cant see how....

    2) When you reach the end of the tape, it obviously just runs free and flaps about. Do you just watch your time (I am getting about 30 mins out of the BASF metal reels I got with it) and ensure you don't reach the end? Any tips? Is letting it run off one reel likely to cause problems?

    3) I have the ASC timecode centretrack unit, any tips for using this?

    4) I have 2 dolby 361s, should I bother using them when tracking, or on playback? Surely they are only of use if going to cassette tape? Can I just ignore them?

    I realize I am going to have to persevere alone for much of this, but any help would be appreciated,

  2. RemyRAD

    RemyRAD Member

    Sep 26, 2005
    Jeemy, I don't recall you saying anything about it?? I hope you got it for a song??

    1) Most of us pros never used the " the little threading circle slot" toward the center of any reel. Just wrap the tape around the core of the reel and let friction do the job after a rotation or two. So you're doing it correctly it sounds to me?

    2) If you have threaded machine properly and the tape runs out, the mechanism should disengage and the reel should come to a stop, within a very short period of time, unless you are in a fast shuttling speed such as fast forward or rewind, in which case it could take many more rotations before it comes to stop. Generally there is no problem with that other than the ends of the tape or leader tape may start looking a little ragged. Hopefully you have allowed more than just a couple of seconds of leader tape, whether it is the magnetic tape itself or a colored paper or plastic without any recording oxide on it before you start to record? The very beginning and the very end's of analog magnetic tape frequently have a greater amount of dropout and slight oxide inconsistencies.

    3) The center track time code device you have was originally intended to synchronize your recorder to a videotape machine. I don't see any purpose in using it if you are simply making stereo or 2 separate mono track recordings? If anything there is risk of time code center track noise crosstalk. Time code does not sound pretty! Now if your intention is to synchronize this analog machine to your computer's multitrack audio program, so as to be able to use it for multi-track recording, so to be able to have that groovy analog sound, you would need an interface that would convert the SMPTE time code output from the synchronizer to something the computer could understand. This may only be possible with some type of computer MIDI interface that have some provisions for reading standard SMPTE time code that can then be synchronized to your software? Mark Of The Unicorn may have something like that?

    4) Your Dolby 361 units are " A " type noise reduction and generally required that you encode to tape, subsequently decoding the tape upon playback. They are not what we would refer to as a " single ended noise reduction unit". There are other units made by other companies that can do just that and require no encoding but these aren't those. These particular units are not designed to be used with cassette decks. THEY ARE DESIGNED TO BE USED WITH YOUR REEL TO REEL MACHINE. They should not be ignored. They provide from 10 to 15 DB of noise reduction in 4 separate spectral bands. So the noise reduction of these professional devices are broadband. In the sense that they are reducing the inherent noise of the tape throughout the entire frequency range. This is in contrast to the Dolby button found on most cassette recorders. That is a consumer version knock off, referred to as " Dolby B and/or C and S" and those only worked primarily in the highest couple of octaves, specifically to reduce only HISS. The " C " made an attempt to also somewhat increase the dynamic range and the " S " version was an attempt to create a consumer imitation of the professional later " SR " or " Spectral Reduction ". That was Dolby's attempt to improve the objectionable qualities to the original " A " version. That version actually sounded considerably better but that is not a reason NOT to use the versions you have. Unfortunately, it must be properly calibrated to the recorder, otherwise you will get "Miss" tracking and she'll make it sound awful. So if you do not know how to calibrate them to the recorder, you should put them on eBay and deal with all the HISS analog recording has to offer. Barefoot analog is still quite lovely sounding and I never used or had any professional Dolby units in any of the studios that I have been directly involved in. 16 and 24 track machines could get pretty noisy if you're recording and mixing techniques were not up to snuff and even if they were, we still live with that little bit of HISS and continued to make lovely recordings that everybody loved.

    Now there is one other purpose oriented use one can use those old Dolby 361 units for. They can make for interesting spectral compressor/processors. They provide both compression and downward expansion in 4 different frequency bands whose thresholds and levels can be independently adjusted from behind the front panel cover. Once you start playing with those controls the units will be useless as noise reduction units but can make for interesting vocal and instrumental processors as they can be used for a type of dynamic equalization and all sorts of cool things if you can't find anybody to buy them on eBay.

    Now I didn't mention about how to calibrate the recorder. To do that you should have a specially produced calibrate a test tape only unavailable from a very few remaining companies. Old used test tape's might get you close but won't get you spot on. Now that's just for playback calibration.

    For recording, you generally had to calibrate the machine to the specific manufacturers different kinds of recording tapes, that was different for all manufacturers and within their differences of product lines. That process requires the use of a sinewave oscillator that can reproduce the full frequency spectrum. You can get into the ballpark by utilizing the tape recorders own volume meters but it was always best to utilize an external test device such as a "VTVM" or vacuum tube volt meter, digital meter and/or oscilloscope, distortion analyzer etc.. That was the only way to obtain a truly calibrated flat response. If you don't calibrate the machine properly it will not give you a faithful recording and reproduction of what you are attempting to record.

    If you are using the large 10 inch aluminum and/or plastic reels in the tape happens to be 1.5 mil in thickness and you are recording at 15 inches per second, then one half hour is what you get. Those are generally 2500 foot reels. There is also a version that is only 1.0 mil. That would yield 45 minutes at an increase of " Print Through", which were faint pre-and post echoes that you could hear during a quiet portion of a louder previous or later section of sound. It was quite annoying and was less a problem with the thicker but shorter running time tapes. The thinner tapes were 3600 foot reels.

    Proper head alignment is a whole other issue but I would rather not go into here.

    Grease pencil and razor blades along with a specific splicing tape and not Scotch tape was also a necessity along with something referred to as a " splicing block" which that machine, depending on the age, may have built in?

    Analog editing is fun!
    Ms. Remy Ann David
  3. Jeemy

    Jeemy Well-Known Member

    Sep 19, 2003
    Sounds like I've been pretty lucky. Yup I am running it at the highest speed possible with the 10 inch metal reels, wound correctly by luck (or flaw) and getting 1/2 hour with plenty (2-3cm) of spare tape at the front and end which I expect to be a little slow/fast so to be avoided - and you mentioned dropouts etc, I concur.

    I paid £300 for this, the Dolbys and the other stuff you mention - the Ampex calibration tape which appears just to need a peak voltage reading to calibrate, watching out for fake peaks, and what is called an Adams-Smith Zeta Three which does the syncing up to DAW or other machines.

    Unfortuntately, although I got the full manual which is hard to find, the Zeta appears to be faulty and a system reset doesn't help. It may just be unhappy at not receiving timecode so next jobs are to:

    1) cable in timecode to the Zeta and find out if it works. If not, I have a guy and although they are rare, they are cheap.

    2) Start running snare hits from the multitrack out to the tape and trying to re-import them, see how they sync without and with timecode.

    3) Learn how to calibrate the Dolbys to the recorder. Why not? It is possible they were already calibrated and therefore I dont need to touch them, but doubtless they will have slipped out.

    Anyhow, once I find out if the timecode works then I can work on syncong to DAW.

    Although I have a suspicion, the only reason I wouldn't sync is tape slippage/speed variation right? And any amount of smpte isnt going to sort that. So why dont I just track to tape (I want to use this on guitars and mix bus work), import back to DAW and do some editing in there - thats what DAW is for, right?

    Thanks for your help Remy, thats superb.

    FYI I had the front panels off the dolbys and only saw 2 trim pots from memory, but i will check.

    Also FYI, the machine does indeed have the splicing block, I hope never to have to use it as I am simply using this machine as an effects processor when all is said and done......
  4. JoeH

    JoeH Well-Known Member

    Jun 22, 2004
    Philadelphia, PA/ Greenville, DE
    Home Page:
    Remy, you'd better be writing all this down yourself for that book someday! (And before you forget it! hahaha)

    I was going to answer parts of this one, but you more than covered it all.

    My only other comment was to say make sure there's no wrinkles or lumps on the take-up reel when he first threads the tape. If the tape is wound tails-out and stored long term, any bumps or lumps in the pack makes for bad mojo further down the road.

  5. RemyRAD

    RemyRAD Member

    Sep 26, 2005
    Jeemy, you really don't need the synchronizer at all! If you want that analog sound in your DAW, there are a couple of suggestions to try without the synchronizer.

    1) record everything to the computer. When you are done recording to the computer, Route a track to the output of your DAW, plug that into your analog machine and put the analog machine into record, playback monitor. Take the output of the analog machine and feed it in to the other (another) track of the computer. Since this will actually be transferring in real time with only the delay between record and play head, you will be able to later slip the computer track ahead, to bring it back in sync with the original DAW recorded track quite easily.

    2) But! You can actually record to be analog machine directly while taking the playback output from the analog machine and simultaneously recording to your DAW. To accomplish an overdub session this way, you will be dealing with the delay between record and playback head on the analog machine. This will require a very specific fudge. The delays will be difficult to deal with but not impossible thanks to the nonlinear nature of our current software capabilities. Each time you overdub, you will have to adjust the delays for each track by retarding the previous tracks on the DAW.

    Trying to deal with the synchronizer to keep the analog machine running in sync with your computer is going to be a major problem. You are certainly welcome to school around with it until you lose your mind but you would be much better off if you just purchased yourself a multitrack analog machine. I know of 2 perfectly good OTARI MTR90, 24 track machines in lovely condition for $2500 US, each. You are going to waste so much time trying to synchronize 1 analog channel at a time but it's really counterproductive and counter creative. Certainly fun if you have nothing better to do with your time?

    Besides if you are doing the transfer from analog to your computer in real-time, you will avoid all of the print through problems since it won't have the opportunity to print through.

    Let's figure out how difficult we can make something?
    Ms. Remy Ann David
  6. Rosemary

    Rosemary Guest

  7. dementedchord

    dementedchord Well-Known Member

    May 11, 2006
    $ .02

    damn she's good... btw way remy hi hows dc? i lived in reston and woodbridge for awhile...
  8. TVPostSound

    TVPostSound Well-Known Member

    Feb 15, 2006

    Dolby units need to be calibrated on at least a daily basis, along with your tape machine. I remember doing up to 5 full record alignments in a day.
    (The term "record alignment" means record, sel-sync, and repro alignment)

    Belive it or not, in the tape days, whether an intern or student, you touched nothing in the studio until you could align tape machines in your sleep.
    That and clean the mixing desk with a jar of Windex, and a big box of Q-Tips!!!!!!But thats another nightmare.

    What speed are you running??? 7.5 ips, and 15 ips benefit greatly from Dolby A.
    At 30 ips, I would not use Dolby noise reduction.
  9. TVPostSound

    TVPostSound Well-Known Member

    Feb 15, 2006
    Ill disagree with RemyRAD here, if you are only using the machine to record, and rerecord to a DAW, then skip the Dolby A.

    My brain cells from 20 years ago are coming back!!!

    The Dolby A was designed to keep noise from compounding during tape to tape transfers. As we mixed tracks to 9 through 22 on a 24 track, from a source 24 track, we then mixed and bounced them to stem pairs on 1 through 8, then those stems were combined to analog 1" video tape, Dolby noise reduction was needed.
    You can see the multiple paths there.

    It makes no sense to encode and decode only for a single transfer back to digital. Especially if the 361 is not properly calibrated.

    If you intend to do it anyway, make sure the cards are CAT22
  10. RemyRAD

    RemyRAD Member

    Sep 26, 2005
    dementedchord, Reston is a nice place still and the whole area has grown like wildfire. I don't get down to Woodbridge much but I do try to make it to Skyline Drive on the motorcycle whenever I can.

    Although TVPostSound doesn't quite agree with me regarding the Dolby's, which is OK since I wasn't doing what TVPostSound was doing. I do remember those original beasts the "A301's", when there wasn't much more than 4 tracks on 1/2" tape. Dolby really never made any thing sound better, just quieter.

    I loved tracking at 30 IPS without any noise reduction
    Ms. Remy Ann David
  11. TVPostSound

    TVPostSound Well-Known Member

    Feb 15, 2006
    Those were the days. :cool:
  12. Cucco

    Cucco Well-Known Member

    Mar 8, 2004
    Tacoma, WA
    You're not missing anything...

    There's a reason why they call it "Hoodbridge"

    The only positive thing about Woodbridge is that they're putting in a Wegmans soon.

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