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#1
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HELP: 1/4" RtR Tape Speed Problem
I am converting a 3" 1/4" 4-track reel-tape to CD. Trouble is, the
beginning is playing back fast and high-pitched (hand-in-hand), but the tail is slow and low-pitched. This implies to me it is a section from a larger reel of tape, but on a small reel. I am currently capturing at 3.75ips. Is there a way of balancing out the speed errors? I tried using a small-spool reel for takeup, but to no avail. Should I try transferring the tape to a larger spool, to simulate the suppossed former reel, or am I way off on that one? My thought about that is that it may have been from a larger, 7.5ips reel Any ideas? Thanks, Dave Schein II -----Insert "Cheesy Promo Signature"----- Dave Schein II, CSO Printergy, Inc. - www.printergy.com DOCHighway, Inc. - www.dochighway.com CDs, DVDs, Scanning, Document Management, Knowledge Sharing... ...The Future! 2066 York. Rd. Suite 205 Baltimore, MD 21093 410-561-8436 - TEL 410-561-1220 - FAX 443-803-2119 - Direct -----End "Cheesy Promo Signature"----- |
#2
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""Granma" Dave Schein II, CSO" wrote in message
news:26%te.393$al.359@trnddc07... I am converting a 3" 1/4" 4-track reel-tape to CD. Trouble is, the beginning is playing back fast and high-pitched (hand-in-hand), but the tail is slow and low-pitched. This implies to me it is a section from a larger reel of tape, but on a small reel. I am currently capturing at 3.75ips. Is there a way of balancing out the speed errors? I tried using a small-spool reel for takeup, but to no avail. Should I try transferring the tape to a larger spool, to simulate the suppossed former reel, or am I way off on that one? My thought about that is that it may have been from a larger, 7.5ips reel Yes. Transfer the tape to a reel with a larger hub. For the tape you have I would probably reach for a large hub seven inch reel. On all but some dictation machines and perhaps some older, small, portable, battery operated, tape decks the tape is driven at a constant speed from one end of the tape to another. If the hold-back and take-up tensions on the feed reel and take up reel are too high, the tape will slip between the steel capstan and the rubber idler causing speed variation. That sounds like your problem. Steve King |
#3
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In article 26%te.393$al.359@trnddc07, \"Granma\" Dave Schein II, CSO
wrote: I am converting a 3" 1/4" 4-track reel-tape to CD. Trouble is, the beginning is playing back fast and high-pitched (hand-in-hand), but the tail is slow and low-pitched. This implies to me it is a section from a larger reel of tape, but on a small reel. I am currently capturing at 3.75ips. Reel to reel tapes should maintain a consistent speed all the way through, regardless of the size of the reel. Are you sure your deck is working properly? If the tape is somehow recorded with a gradual speed change, it's possible that if you figured out the correct pitch for each end, you could find a program for you computer that would make the correction from head to tail. I used Peak, but I've never tried to do anything like that before. See ya Steve -- VIP RECORDS: Rare 78 rpm recordings on CD in great sound FREE MP3s OF COMPLETE SONGS http://www.vintageip.com/records/ *#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#* The Quest for the BEST HOTDOG in Los Angeles! http://www.hotdogspot.com/ *#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#* Rediscovering great stuff from the past! http://www.vintagetips.com/ |
#4
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\"Granma\" Dave Schein II, CSO wrote:
I am converting a 3" 1/4" 4-track reel-tape to CD. Trouble is, the beginning is playing back fast and high-pitched (hand-in-hand), but the tail is slow and low-pitched. This implies to me it is a section from a larger reel of tape, but on a small reel. I am currently capturing at 3.75ips. No, you have a tape that was made on one of the Japanese 3" recorders that drove the reel at constant speed rather than using a capstan. These were popular for dictation applications in the early seventies. The speed is not constant; the rate of rotation of the take-up reel is. These things have a lot of flutter but that was fine for the application. Most of them are half-track. Is there a way of balancing out the speed errors? Yes, you can use a piece of equipment that I designed and used to sell, which connects to the varispeed input on the ATR-100 and allows you to ramp speed up or down in a controlled fashion. Or you can try and find one of the Concord or Sony recorders that the tape was recorded on. I tried using a small-spool reel for takeup, but to no avail. Right. Should I try transferring the tape to a larger spool, to simulate the suppossed former reel, or am I way off on that one? My thought about that is that it may have been from a larger, 7.5ips reel No, the reel size will not change the speed. On a conventional tape machine, the tape is driven at constant speed by a capstan and so the tape speed is independant of reel size. Any ideas? Easiest thing might be to write some code to do this in software once you have acquired the signal. Do your playback with the NAB EQ bypassed, do the varispeed in software, then equalize it in software again. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#5
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I am converting a 3" 1/4" 4-track reel-tape to CD. Trouble is, the
beginning is playing back fast and high-pitched (hand-in-hand), but the tail is slow and low-pitched. This implies to me it is a section from a larger reel of tape, but on a small reel. I am currently capturing at 3.75ips. Is there a way of balancing out the speed errors? I tried using a small-spool reel for takeup, but to no avail. Should I try transferring the tape to a larger spool, to simulate the suppossed former reel, or am I way off on that one? Way, way off. The reel size has nothing whatever to do with the tape speed. Open-reel tape is constant-speed. However... What you have is a tape made on a rim-drive machine. These were fairly common in the earliest days of transistor portable tape recorders, because capstan drive was much too expensive. Instead of a capstan and pinch roller moving the tape at a steady speed, the take-up reel turns at a constant rate. The tape speeds up as the diameter of the tape on the reel increases -- hence, fast at the beginning and slow at the end, when played back at constant speed. The only thing I can think of is to copy the recording to a minicassette (NOT microcassette) dictation machine such as a Lanier (which are also rim-drive), and use the recorder's variable-speed playback to adjust. |
#6
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"Scott Dorsey" wrote in message
... \"Granma\" Dave Schein II, CSO wrote: I am converting a 3" 1/4" 4-track reel-tape to CD. Trouble is, the beginning is playing back fast and high-pitched (hand-in-hand), but the tail is slow and low-pitched. This implies to me it is a section from a larger reel of tape, but on a small reel. I am currently capturing at 3.75ips. No, you have a tape that was made on one of the Japanese 3" recorders that drove the reel at constant speed rather than using a capstan. These were popular for dictation applications in the early seventies. The speed is not constant; the rate of rotation of the take-up reel is. These things have a lot of flutter but that was fine for the application. Most of them are half-track. Is there a way of balancing out the speed errors? Yes, you can use a piece of equipment that I designed and used to sell, which connects to the varispeed input on the ATR-100 and allows you to ramp speed up or down in a controlled fashion. Or you can try and find one of the Concord or Sony recorders that the tape was recorded on. I tried using a small-spool reel for takeup, but to no avail. Right. Should I try transferring the tape to a larger spool, to simulate the suppossed former reel, or am I way off on that one? My thought about that is that it may have been from a larger, 7.5ips reel No, the reel size will not change the speed. On a conventional tape machine, the tape is driven at constant speed by a capstan and so the tape speed is independant of reel size. Any ideas? Easiest thing might be to write some code to do this in software once you have acquired the signal. Do your playback with the NAB EQ bypassed, do the varispeed in software, then equalize it in software again. Not really necessary to write your own varispeed code; DC-SIX has a function that will do it quite handily. I use it often for correcting 78s that are off-pitch. You can set the beginning of the file to a different setting than the end,. and the software will ramp between the two settings. Peace, Paul |
#7
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"Granma" Dave Schein II, CSO wrote:
I am converting a 3" 1/4" 4-track reel-tape to CD. Trouble is, the beginning is playing back fast and high-pitched (hand-in-hand), but the tail is slow and low-pitched. This implies to me it is a section from a larger reel of tape, but on a small reel. I am currently capturing at 3.75ips. Is there a way of balancing out the speed errors? This can be done in the digital domain by working with the pitch-changing features of common computer audio editing software such as Audition/CE. |
#8
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William Sommerwerck wrote:
I am converting a 3" 1/4" 4-track reel-tape to CD. Trouble is, the beginning is playing back fast and high-pitched (hand-in-hand), but the tail is slow and low-pitched. This implies to me it is a section from a larger reel of tape, but on a small reel. I am currently capturing at 3.75ips. Is there a way of balancing out the speed errors? I tried using a small-spool reel for takeup, but to no avail. Should I try transferring the tape to a larger spool, to simulate the suppossed former reel, or am I way off on that one? Way, way off. The reel size has nothing whatever to do with the tape speed. Open-reel tape is constant-speed. However... What you have is a tape made on a rim-drive machine. These were fairly common in the earliest days of transistor portable tape recorders, because capstan drive was much too expensive. Instead of a capstan and pinch roller moving the tape at a steady speed, the take-up reel turns at a constant rate. The tape speeds up as the diameter of the tape on the reel increases -- hence, fast at the beginning and slow at the end, when played back at constant speed. The only thing I can think of is to copy the recording to a minicassette (NOT microcassette) dictation machine such as a Lanier (which are also rim-drive), and use the recorder's variable-speed playback to adjust. Other methods (if you are sure it really was recorded on a spool-drive machine as opposed to a capstan-drive one): Method 1) Place the approprite sized take-up spool on a variable-speed turntable and use it to draw the tape through the playback machine. I have done this successfully using a Lenco turntable and a Ferograph 7, which has an open deck layout, allowing the tape to be easily threaded so as to by-pass the capstan. The two units must be fairly close together (or the span of tape must be supported) to prevent the loose tape from fluttering around. If you start off with an empty 'cine' take-up spool and find the speed change from end to end is too great, it means the core diameter of the spool is smaller than the one the tape was recorded on. Try partially pre-filling the take-up spool with a pile of scrap tape, then lace your tape on top of it. After a few attempts, you will find the size of pile needed to give you roughly the correct starting diameter. After that, you can use the turntable speed for fine adjustment. Method 2) ...entirely at your own risk. If the tape playback machine has a synchronous or semi-synchronous motor, feed it with variable frequency 'mains'. Only consider this method if you are electrically qualified and experienced. Use a signal generator at around 40 - 80 c/s to drive public address amplifiers giving 100 volt line output. In the UK, two amplifiers in series (or a step-up transformer) are needed, but in the US it should be possible to use only one amplifier. Connect the output of the amplifiers to the mains input of the tape playback machine and adjust the frequency to get the required playback speed. This works over only a limited range of frequency and a lot will depend on the design of the tape machine and ampifier, whether they are robust enough to take this kind of mal-treatment. Keep your wits about you and continually check for the signs or smells of overheating components. If the amplifier has a tendency to oscillate or generate strong harmonics under overload conditions, it will burn out the resistors in any switch-suppressor networks of the tape machine. I have used this method with a pair of Quad 50E amplifiers in series to get 200 volts to operate a Ferrograph 7 and an assortment of small dictating machines for various formats. http://www.poppyrecords.co.uk/other/mandela/dictabelts.htm If you have to alter the mains input adjuster to get the machine to operate on the reduced voltage, don't forget to put it back to normal mains voltage afterwards! -- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk |
#9
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Word!
Thank you for the input. I am using an AKAI 1722-II, which I believe to be capstan drive. The recording was made some years ago on a GE recorder, that may well be spool-driven. Thank you for all the information. I'll take a look at that DC-SIX thing. -gran "Paul Stamler" wrote in message ... "Scott Dorsey" wrote in message ... \"Granma\" Dave Schein II, CSO wrote: I am converting a 3" 1/4" 4-track reel-tape to CD. Trouble is, the beginning is playing back fast and high-pitched (hand-in-hand), but the tail is slow and low-pitched. This implies to me it is a section from a larger reel of tape, but on a small reel. I am currently capturing at 3.75ips. No, you have a tape that was made on one of the Japanese 3" recorders that drove the reel at constant speed rather than using a capstan. These were popular for dictation applications in the early seventies. The speed is not constant; the rate of rotation of the take-up reel is. These things have a lot of flutter but that was fine for the application. Most of them are half-track. Is there a way of balancing out the speed errors? Yes, you can use a piece of equipment that I designed and used to sell, which connects to the varispeed input on the ATR-100 and allows you to ramp speed up or down in a controlled fashion. Or you can try and find one of the Concord or Sony recorders that the tape was recorded on. I tried using a small-spool reel for takeup, but to no avail. Right. Should I try transferring the tape to a larger spool, to simulate the suppossed former reel, or am I way off on that one? My thought about that is that it may have been from a larger, 7.5ips reel No, the reel size will not change the speed. On a conventional tape machine, the tape is driven at constant speed by a capstan and so the tape speed is independant of reel size. Any ideas? Easiest thing might be to write some code to do this in software once you have acquired the signal. Do your playback with the NAB EQ bypassed, do the varispeed in software, then equalize it in software again. Not really necessary to write your own varispeed code; DC-SIX has a function that will do it quite handily. I use it often for correcting 78s that are off-pitch. You can set the beginning of the file to a different setting than the end,. and the software will ramp between the two settings. Peace, Paul |
#10
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""Granma" Dave Schein II, CSO" wrote in message news:0lfue.4456$Uj.1511@trnddc08... Word! Thank you for the input. I am using an AKAI 1722-II, which I believe to be capstan drive. The recording was made some years ago on a GE recorder, that may well be spool-driven. Thank you for all the information. I'll take a look at that DC-SIX thing. It's a useful program for editing and cleaning up audio if you use it with restraint and taste. The interface is kinda clunky and at least on my machine it crashes more than I'd like, but it does the job well for the price. Peace, Paul |
#11
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yeah, i just took a look at their site. For my temporary purposes, I don't
know that it's worth the $200 for this $30 job, but I will keep it in mind for the future. I use SoundForge for the other stuff, for the most part. I should really put that $200 toward the upgrade for that, I believe. Thank you for the help, Paul, Dave "Paul Stamler" wrote in message ... ""Granma" Dave Schein II, CSO" wrote in message news:0lfue.4456$Uj.1511@trnddc08... Word! Thank you for the input. I am using an AKAI 1722-II, which I believe to be capstan drive. The recording was made some years ago on a GE recorder, that may well be spool-driven. Thank you for all the information. I'll take a look at that DC-SIX thing. It's a useful program for editing and cleaning up audio if you use it with restraint and taste. The interface is kinda clunky and at least on my machine it crashes more than I'd like, but it does the job well for the price. Peace, Paul |
#12
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""Granma" Dave Schein II, CSO" wrote ...
I am converting a 3" 1/4" 4-track reel-tape to CD. Trouble is, the beginning is playing back fast and high-pitched (hand-in-hand), but the tail is slow and low-pitched. This implies to me it is a section from a larger reel of tape, but on a small reel. I am currently capturing at 3.75ips. You didn't state *how much* of a pitch change. If it is slight, it may have been due to reel/hub size and tension issues, but if large, maybe from an old hub-drive recorder? Is there a way of balancing out the speed errors? I'd capture it using CoolEdit/Audition and use the "Pitch Bender" function where you can set the beginning and ending factor and apply the change over the entire length of the capture. It even shows you a graph of change vs. time so you can set up a non- linear change if necessary. |
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