Preserving the stories of significant individuals in sound recording generally and magnetic recording specifically is a major project of MOMSR. The Museum’s goal is to document the stories of those persons who contributed significant inventions, manufactured equipment and who engineered and produced audio recordings, especially in the areas of music, broadcast, film/video and science. These interviews will be available on MOMSR’s web site and in the permanent facility when it is created. These interviews have also been made available to the Audio Engineering Society (AES) and the National Academy of Recording Arts and Sciences (Grammy’s).
Remy David talks about her recording history
The Museum of Magnetic Sound Recording greatly appreciates Mx. Remy Ann David/Crow Mobile providing us with the following information on her recording history.
I would love to contribute yet more information regarding the history of magnetic recording and some other recording studio and brought just trivia I've had through my over 50 years.
Heck, my first production system at nine years of age was a Western Electric 23 C, radio production console from 1943. A Viking NAB custom-built cartridge recorder. REK-O-KUT transcription turntable, Bogen variable speed turntable. Magnacord 10.5 inch real capacity studio record or the P-6 as I recall? Not that other popular smaller recorder that only accepted 7 inch reels which I think was that P-60? Maybe mine was the PT-6? I'd have to dig out the picture of information to get that straight. And an Akai, tube, one quarter track stereo recorder. This recorder had an adjustable playback head mechanism allowing for the playback of 1/4 inch, 1/2 track stereo recordings. And it was pretty funny with both side recorded, 1/4 track stereo recordings. With their heads in the wrong position, you would get one forward channel on side one and one backward channel from side two, which was always good for a laugh.
My microphone was a Electro-Voice, 636 Slimair, Omni directional dynamic microphone. the 2 turntables were pre-amplified by a SHURE, stereo tube preamp, with switch selectable function variations. It could be switched as a flat high impedance, fixed again microphone preamp, NAB 7.5 IPS playback curve, RIAA phono curve and special. Where special, sounded like a lot more high-frequency boost, beyond what the high impedance microphone selection would provide. And today, I still have that preamp which was recently rebuilt, restored and that same microphone in my rather extensive and esoteric collection of valued microphones. My headphones were a pair of, like, B-17, Flying Fortress, radio communication headphones. Of which I modified to be my first pair of stereo headphones. Which of course changed my life, forever! LMAO. And I actually have one picture of myself at age 9, headphones on, mouth open and doing my DJ thing, in 1964. I went on to produce radio commercials for my fathers advertising agency with a professional announcer and copywriter he had employed. Prior to that, he was cutting all of his commercials down at United Sound Systems, in Detroit. Which I have often gone down to, with him, on a Saturday afternoon when he was either cutting commercials with other announcers or a kid for a local car dealer. Otherwise he was often hired as a session violinist for many of the early R&B acts coming out of Detroit in the 1960s.
I did this for my father between the ages of nine and 12. By the time I was 12, the advertising agency started to falter and dad had to give up his, private, personal and luxurious office building. The equipment all ended up in the basement of our house. And dad went back to producing commercials at United Sound Systems. Until one day...
I already knew from my multiple visits to all of the major radio and TV stations in the Detroit market, along with the recording studios, I knew by age 7, this was what I was put on the planet to do. And that lump of equipment in the basement... was begging me to reconnect it all. Well... since I was already the Capt. of the Audio Visual department at my elementary school, I better get to work on this equipment, sitting in the basement. And later that evening... I was up and running. And promptly went back to cutting commercials for dad. He would bring the announcer into our basement, set him on the other side of the room and I would use headphones cutting dry tracks of the announcer. I would later go back, edit the announcer tracks and then mix him with music and/or the jingle. I then make the necessary copies for the distribution to the radio stations and/or TV sound for commercials. I continued to do that for dad until the eventual divorce and my mother's move of us to the Baltimore/Washington DC area.
Those last two years of mine at 14 & 15 years of age, were some of my most progressive early times of my career. At 14, I acquired my NOVICE ham license. I had purchased a new Radio Shaft DX-150 A, international shortwave receiver. I also acquired a Knight Kit T-150, CW/AM, crystal controlled/VfO, ham transmitter. And I had also learn how to directly couple the output of my Western Electric radio console into our telephone lines. I had to modify a desk telephone with a jack and a switch. And in a sense, I created a very rudimentary telephone hybrid at 12 LOL. Of course you probably can imagine, I also did something slightly illegal as a stupid teenager. I, detuned the VFO, in that transmitter. It allowed me to shift my broadcast frequencies over to the international shortwave broadcast frequencies. Whoops! LOL. Loaded into a 50 foot inverted L, dipole antenna, with a 20 foot height at about the highest altitude in the northern Detroit suburbs, probably gave me a fair amount of effective ERP of the 150 W amplitude modulated output from this transmitter LOL?
Now I knew that I was playing with fire with what I was doing. So my broadcasts were usually under three hours long and never on the same frequency twice. One day, I disconnected my dipole antenna and connected my output load, 150 W light bulb. I then proceeded to connect a pair of parallel wired 9 V batteries to my transistorized DX-150 shortwave receiver. I than bungee corded that my bicycle handlebars. I artfully threaded some zip cord around the frame of my bicycle and connected it to the antenna terminals. I plugged in my headphones (with the world's first Walkman) and started riding my bicycle down Woodward Avenue and 11 mile road. And about 1/2 mile past 9 mile Road, I lost my signal. OMG! And that was without an antenna connected to the transmitter! So I hightailed at home. Then I connected the antenna and repeated my ride. By the time I got down to the same location 1 1/2 miles away, signal strength still indicated 9 out of 10 on the RF meter in the DX 150. Holy cow! OMG! Better knockoff is nonsense before I get caught. And do it the right way.
A few months later... I had my FCC, Third Class, Radio Telephone License. Which I had studied for, for all of four days. And two days later, I was on the air at WOAK, 88.9, the Voice of Royal Oak, Michigan, at Dondero High School.
Now the progression up to this point, is rather fascinating. I was diagnosed with HA-ADD, in fifth grade. And while I was tested because I was thought to be retarded, of the multitude of IQ tests I was given, they all kept coming back in the most decidedly, genius level. I was absolutely miserable in school, scholastically. I was like Bart Simpson, an underachiever and proud of it. Well not really proud. Honestly it was quite befuddled with the slow boring nature of schooling. I was already quite aware of my own talents. In junior high school, many of the papers we were assigned to hand in as homework, I never did. Instead, I presented it as a multi-person radio show production. It didn't matter if it was English or history or science. And for the science productions, I frequently leaned towards the environment because the god damned pollution was so horrific with Detroit in its heyday. And I did that throughout junior high.
I knew that Dondero was one of the few high schools in the country to have an FM educational radio station. My folks had already separated and I knew that divorce and the move was imminent. The impending situation made me realize I was only going to have one half of my freshman year at that high school in which to take broadcasting. So I informed my counselor when designing my curricula that I did not care what other courses or classes they put me in but that I must absolutely have, broadcasting, my first year, my first semester. I was assured no problems because I was going to be one of the first whose schedule would be taken care of with this newfangled computer thingy the Royal Oak Board of Education had just installed.
Upon my first day, I can hardly wait to receive my schedule. Of course everyone else was equally excited about their own selections. When I got my schedule, I was completely dumbfounded, shocked out of my mind, WTF with this?! Yeah, the computer did a great job... I had this course that I apparently selected that started with a B and ended with a G. Back then, they called it Baking. And that year it was later changed to Home economics. The only problem was... the class was full. To which they informed me, I would have to take it in my sophomore year. I was completely outraged! I informed them they had broken a contract with me a binding contract. I demanded that they fulfill the contract. They could not. They can only give me a study hall.
So that's when I went to the Broadcast Teacher, Sheila Bickol. She said I needed that license and to just simply order it from the FCC. Which I did but never received. So I went to Lafayette or Olson's and picked up a third party study guide. I studied it Monday through Thursday. I cut school on Friday to go take the test. The nice lady told me I passed. I never did good on tests of any kind. So I asked her what my score was? She told me they don't tell people their scores only whether they passed or failed. Well the look of a 15-year-old's face must've done it? She leaned down and whispered to me that my score was 100%. Oh my gosh golly wow! So how long until I get it? She indicated about 10 days to two weeks. Well sure... but that's like a year to a 15-year-old.
When I awoke Saturday morning, I was still quite proud of myself. Then mom lets me know I have received some e-mail from the FCC. Well God dammit...that must be the stupid FCC study guide? I was disgusted and going to just tear it in half. But then curiosity got the better of me as to how different their study guide was from the third party study guide? I was in complete disbelief as to what I extracted from the envelope. It was my license. How is that possible? It wasn't even 24 hours later! This lovely federal FCC employee Lady, a Federal Government employee, must have immediately printed up my license upon my departure at 3:30 PM the previous day? She must've then, simply walked into the back door at the Detroit Post Office and perhaps asked a friend to send this license out the next day? Mail service faster than today's was unheard of back then.
So on Monday back to school, I traipse on into Mrs. Bickol's and proudly hand or my license. It was only the previous week I had asked how to obtain one. She knew immediately this was a forgery! And she became quite upset. She told me it took the kids the entire first half of the school year before they were ready to even take the test for the license. Upon passing the test, it would always take between 10 days in two weeks. She was ready to call the authorities on me. I told her I knew that's how it was supposed to go but it didn't. I told her this was the real deal honest to God. So she picked up her phone and called the FCC office in quite a huff. And then her expression changed into a smile and a thank you. She looked at me and asked me if I wanted to sign off. And I was the only kid in that school to have ever gone on the air without ever taking the class, within the first two weeks of school. So everyone was quite buzzed about me. And I was given pretty much free reign to do whatever I wanted to do. And I've of course wanted to be one of the music DJs, of which I was granted. And everyone else had to come up with those kinds of shows I had done in junior high school.
In the middle of the school year, it was time to move to Baltimore and all of that radio station equipment had to go into the trash. OMG all that was going to go was this lousy pair of Sony tape recorders. A 250 deck and a 630 recorder with the integrated amplifier and full range six-inch pair of speakers. Along with that Bogan turntable, preamp and microphone. I also had the Presto 800 that my grandfather had owned now in my possession.
Of course as I went to the new high school in Baltimore, I inquired about the possibility if it had any radio station. I was told they did. I was so happy! And they probably gave me a tour of the closet that the janitor used at the back of the lunchroom. A Bogan industrial PA amplifier in a wall mounted rack and a Radio Shaft record changer with a push to talk base station CB microphone. That ain't a radio station I told them. And it only broadcast during the lunch hour anyhow. It was then I knew, I had to build a real radio station for the high school.
I took that Presto 800. I junked the transport. I looked at the schematic for the electronics. This thing had three microphone inputs and a line level input. So I set out to modify this thing. I removed all of the pre-emphasis and de-emphasis networks. I installed center off, double throw switches for program, off and audition/cue. To microphone inputs. Two turntable inputs and an auxiliary line/tape recorder input. School Electro-Voice 664 uni-directional dynamic microphone and a pair of decent cheap manual modified turntables. And this new radio station suddenly became a big hit of its own. Everybody wanted to be on the high school radio station. 30-50 students became involved. We were then granted the use of the space of the large projection booth at the back of the auditorium. We had a separate record library in the HVAC blower room. One half of the room was the news department and associated microphone. And the disc jockey position that also included an interview microphone. The broadcast day began from the moment the school doors were unlocked and throughout the entire day in the lunchroom that also serves as the central study hall. Broadcast sometimes continued throughout the after school hours during sporting events and other social school events such as plays, musicals, baking fund raisers, etc. And quite a few people went on to broadcast careers because of what I had done. Upon my departure, the local AM rock station donated all of their broadcast equipment after upgrading their own studios.
Not that same point in time, because it was not a real broadcast facility, I was also the youngest engineer who had a regular two day per week schedule at the Community College of Baltimore's, WBJC-FM, 91.5 NPR affiliate station. I had an Opera show on Thursday evenings and jazz on Saturday afternoons. I also produced educational talk programs from their production studio, all in 1971-73.
My heart really was in music and productions in recording studios. In 1972 the Yellow Pages only had one half dozen studios in Baltimore. Only three of them could be considered music production oriented studios on a contemporary level. The biggest in town was Flight Three Recordings Inc.. It was a spin-off of a previous Recordings Inc. that consisted of Louis R. Mills Junior, Joe Bradley, Burgess McNeil and his young engineer they hired by the name of George Massenburg who was enrolled at Hopkins for electrical engineering. For whatever reasons, those folks parted company. Joe Bradley opened his own place with a Spectra Sonics console and Scully 100-16. Flight Three had three rooms. The money maker was Louis Mills, the president. He was one of the premier radio/TV voiceover commercial producers on the East Coast. His partner and VP, Craig Kenney broad enough to the table for a second voiceover production studio and a rather large music studio featuring a beautiful API console and this brand-new MCI JH-10-24, making this studio complex the first and largest 24 track complex, south of New York City. Not even Sigma Sound in Philadelphia was like this new breed of studio. And in my searching for a studio job at 16 years of age, Craig offered me the position of chief maintenance engineer at Flight Three. I declined his offer because I knew I was talented enough to do the job but informed Craig that at 16 years of age, that was far too much responsibility for 16-year-old. So I suggested he hire my mentor Thomas M. Bray which he did. The following year, I got that production job I wanted.
At the same time this was going on, George Massenburg had also split off and had also dropped out of Hopkins after three years. He teamed up with Burgess McNeil. And with another backer, ITI was founded. Burgess was the actual electrical engineer behind George's concepts and requests, specifications. And the ITI parametric equalizer ME-230 was born. George quickly designed and built his own custom console. He also became known as the hottest music engineer in the Baltimore-Washington market area. I met him when I was 15 at his then, brand-new studio, ITI. My high school band director took us on a tour there. And none of those kids knew what was in that control room except for me. 3M M-56 and Dolby A, rack. A couple of two track Scully's, his custom ITI console, JBL L-100's (4311 consumer version that looked nice). Neumann KM-84's all about the studio.
I am actually starting to prepare to write a book that actually quite possibly produce a documentary film about my life in the broadcast and music recording field. Numerous people keep making this request of me to do this. And for other reasons of which I will not go into detail here about. So anything that helps to preserve this unique history we've all had the incredible pleasure and experience of being a part of, I'm all for. I consider myself one of the last of the great engineers of the Golden age of the broadcasting and recording arts and sciences.
Today at 57 years of age and having recovered from a deadly health condition that slapped me down for a few years and really screwed my business, I am still attempting something of a comeback.
The remote truck I built 23 years ago may also be of some interest to you? You of course I've heard of this new movie produced by Dave Grohl formally of the famous Nirvana and founder of the Foo Fighters, movie? The movie is entitled Sound City. Most of the movie surrounds that console and control room that produced so many hits from these now legendary stars. And while they talk and laugh about that 1970s control room with the beige carpeting on the control room walls, with historic pictures and film of that control room, you are looking right at the identical, and I mean identical, control room sitting inside my truck on six tires for the past 23 years. And it's my www.crowmobile.com. All vintage, American, British, discrete transistor, legendary equipment stuff (of course with the exception of the multiple digital effects devices which have also been present in analog control rooms since the early 1970s).
And my first machine was the MCI, JH-10-16 that was purchased used from Curtis Mayfield's studio before his accident and paralysis. Followed by my Ampex MM 1200-24 that was pieced together. I mean this thing did not even have a transport wiring harness much less the transport logic control cards or full function remote control. And missing eight channels of electronics and the chassis to those 17-24. Then it sure wasn't fun, in spite of the fact that I wasn't authorized and factory trained Ampex service technician, when the wiring documentation has typos in them. One in particular was the motion sensing was indicated backwards in the documentation. Of course the machine wouldn't run correctly because ya know ya thought it was going in the opposite direction it was going in LOL. It wasn't funny at the time. There were also reversals in LED polarity indications.
Now about some of that MCI stuff. For almost 2 years I lived three blocks away from the factory. He was on the other side of the playground behind my apartment's. I worked for Golnick advertising. It was Leon Golnick was a innovator in syndicated advertising. And it was Leon who funded Louis to also help open Flight Three since they were Lou's biggest customer and benefactor. It was Leon that paid for all of Control Room A. That control room is equipped with a custom Suburban Sound Inc./SSI, Neil Muncey console. Love which was based upon Melcor, 1731 operational amplifiers created by Saul Walker before that company went bust and he started the API company with the 2520 which was his original 1731. And I still have in my possession, most of that operational console minus the 8, API's 550's, which I sold to a friend of mine who is starting a business and needed them. Paul Wolff had just acquired API from DataTronix.
Now my history of magnetic recording goes well beyond that of most. It's not every day you trump world authorities manufacturing analog reference calibration tapes like J. McKnight of MRL as I have. LOL and that's more funny stuff about magnetic recording you should know about. But you won't get any other place than from me
As you can tell I can go on and on and I have much to contribute. And the in-depth situations in the manufacturing side of legendary magnetic audio recorders like the Scully's whom I was the Quality Control Manager and Final Test Technician, in their last days.
Well I think that's enough of a book for your history of magnetic recording? I've got more. One recorder you didn't mention that I currently still have in my possession and need to unfortunately sell is my Lesher 7.5/15 IPS, 1/2 track tube recorder from the mid-1950s. This machine has never been used but a few hours in its entire existence. It was purchased new in the Detroit area. Lesher, to the best of my knowledge, was a professor of electrical engineering, at the University of Michigan, Ann Arbor. He and other colleagues, from what I understand, built quite a number of these recorders. I even most recently heard from someone that knew who had purchased quite a few of those recorders which they had over at Motown studios. The electronics were reminiscent of the Ampex 351 small glass envelope dual triode design. Similar 350/351 transport design. And I actually purchased this machine from the original owner (a friend of the family and a musician) when I was 15. But it was a little too much and so he took it back. Along with the pair of SyncRon CU-7 a.k.a. Fairchild F-22, first United States built large diaphragm condenser microphone utilizing an FET. And that's a piece of American magnetic recording industry. I'd really love to donate this stuff but I really need the money badly though I'll consider all offers. I also have the original manual to that Lesher recorder with what appears to be some possibly factory hand written information may be by Prof. Lesher himself? And I have all of that information and that machine for ya.
If it took you a long time to read through this, I can tell ya, it's taken me eight hours to write it. Or is that 10? Oy vey.
Mx. Remy Ann David/Crow Mobile
I don't think I was the one that told folks to put their stereo tracks on tracks 1 3, with the vocal soloist on track 2? As the crosstalk in this instance, shouldn't be a factor.
Where this application was pertinent, was when dealing with SMPTE timecode. It is so nasty sounding, being of frequency shifting square waves. It always easily cross talked to the next adjacent channel. This is why you would put it on the extreme channels such as track 8, 16, 24. And you wouldn't really want anything else of any importance or solo nature, next to that. Usually folks would just leave a track empty as a guard band. Such as 7, 15, 23.
When you needed more tracks. You could put something like the bass guitar next to the SMPTE track. But then you would also roll off the high-end, to keep from hearing that screeching of the timecode. As you really didn't need much high-end on the bass guitar. (Although I like the high-end on bass guitar LOL.)
When it comes to azimuth error. Every multi-track head, has some gap scatter. And what that means is that the gap, from one channel to the next, could not all be perfectly aligned vertically. So if you were to find that the gap scatter between, say, channels 1 2 was too great? But found that you had less gap scatter on channel 3, when referenced to channel 1. You might want your stereo pair on 1 3. Then putting your soloist on channel 2. Since even with gap scatter on channel 2, that really wouldn't make much difference in reference to the instrumental tracks versus the vocal track. Most of the time none of this really mattered.
Certain signals have the tendency to create more crosstalk than other signals. For instance, drums. You wouldn't necessarily want to put a quiet solo instrument or voice on an adjacent track to say, the bass drum, snare drum, overheads. As you might likely hear those drums cross talking onto your vocal track, for instance. But where it may make less problems if you put the electric guitar adjacent to the drum tracks. Though crosstalk was never really that big an issue, most of the time.
The small amount of crosstalk between left and right channels, is not generally audible. As what is in the left is basically the same as what's in the right. When you have different contrasting sounds between tracks. That's where the crosstalk might be more noticeable and audible. But again, rarely a problem.
There was more problems with print through than with crosstalk. Once print through happens. It can't be undone. This is another reason for storing your masters, tails out. It puts that print through Echo, after the primary sound and not before it. It sounds bizarre when it happens before the primary sound. Like the extremely exaggerated type on that Led Zeppelin song. Iconic now, sure. Not something though you generally want to hear that way, with other content.
With your stereo ribbon microphone. I would generally print most of my stereo stuff on a pair of tracks together. Like Trax 1 2 or seven eight. I wouldn't necessarily separate them. It's going to be in sync and match the other drum microphones, anyhow. So if there was any crosstalk? You'd never know it anyhow.
I think you maybe interpreted what you read, a little off? Crosstalk should only be a problem, with two disparagingly different sources next to each other. Like a flute solo next to the snare drum track. You wouldn't want that. You might want the flute solo track, next to, say, the keyboard track. Then place the keyboard track next to that snare drum track. The crosstalk will be far less noticeable if it's noticeable at all. Between the keyboard and the snare drum. Protecting that solo flute from the crosstalk of the drum track.
When it came to 1/4 inch wide tape, running 4 tracks. Such as on a TEAC 3340. Your stereo pair should be printed to Trax 1 3. Since, 1 3, is left right, on a consumer, 1/4 inch, 1/4 track machine. Since track 2 4, were the other side of the tape. Once you flipped the reels over. As that format, allowing you to record stereo in one direction. At the end of the tape, you would turn it over and record on side 2.
But when using a TEAC 3340. And you've got two channels of stereo drum mix. You could print that on Trax 1 2. With your vocalist on 3. But when played on a consumer 2 track, 1/4 inch, 1/4 track machine. You would get left channel drums and right channel vocal. Since the consumer machine is using channel 1 as the left and channel three, as the right.
By doing it that way, you could play your drums and stereo on the consumer machine. Then you would have to flip the tape over to capture what was on channels 2 4. But it will be backwards, if it had been recorded on a TEAC 3340. At least that way, you could then reverse it. And then you wouldn't have to worry about the azimuth error between your drum tracks. Meaning that the azimuth error between nonrelated tracks, wouldn't cause a problem.
I know this must be completely confusing. I'm just confused trying to write this LOL. This is only pertinent regarding 4 track machines. Whether they are 1/2 inch or 1/4 inch. I've got both 1/2 inch 4 track heads for my Scully and 1/4 inch 4 track heads, also for my Scully. So that gives me the versatility, to be able to produce, 1/4 inch, 1/4 track, stereo consumer recordings and playbacks. On the Scully. As if it was a TEAC 3340. Or if it was like a consumer Sony 630. Which is only to be able to record and play channels 1 3 on side 1 of the tape. And channels 1 3 on side two of the tape. Which is actually the backwards, channels 2 4 when played on a 1/4 inch, 1/4 track stereo machine. Only being able to hear those tracks on the consumer stereo machine, with the tape flipped over for side 2. It will play backwards. On the consumer machine.
So the professional 4 track machines (which also includes the TEAC 3340's), can have tracks printed that will be more compatible with playback on stereo, consumer four track machines. Which are really just two pairs of stereo. One on side one and one on side two.
Not that any of this makes total sense. It doesn't. It's consumer versus professional. Apples and oranges in a sense. Even though they are related. So one can do things, on a professional machine, to make it more compatible with playback, to a certain degree, on a consumer machine that may not have 4 channels of electronics. Given that they are all 1/4 inch machines. Not that this matters to most other professionals. It doesn't. I only mentioned this, since in my younger years, I only had consumer Sony's that were four tracks but only stereo. On 1/4 inch tape.
When it comes to 1 half-inch tape. None of this makes any difference. One half-inch tape can't be played on a 1/4 inch machine. So it's all moot. But ya see, today, I'm archiving plenty of 1/4 inch tape. Some from consumer machines. Some from TEAC 3340's. I'll playback on my Scully with four track, 1/4 inch tape heads. Making my Scully seem like a very expensive TEAC 3340 and sounding way better. Much flatter. Much less distortion. And where the stereo tracks will appear on channels 1 3 forward. While channels 2 4 will play backwards on the 4 track, 4 channel Scully.
Here's an interesting bit of analog tape copying trivia.
When making tape copies of other tapes. When you can... you want to make them backwards. By doing this, you get better transient response when the tape is then played forward. Since impulse sounds, will not start as an impulse but as the trail leading up to the impulse. Which actually makes those transient sounds, sound better.
High-speed reel to reel duplication machines, duplicated everything backwards. When the tape ran out. You didn't have to rewind it. You would just load it up on a machine and play it forwards. No rewinding necessary. This made for faster duplication and better transient response. Since every transient is then ramped up to the transient and not starting with the iimpulse transient. Allowing the electronics to respond more quickly. It's goofy, I know but you can hear the difference. Try it sometime for yourselves.
Just like there is more than one way to skin a cat. There is more than one way to make a tape copy. And make that copy sound better, than it normally would, if you had done it forwards. So we don't want to skin the cat. We want to put the fur, back on the cat. That's a little trickier LMAO.
Now the bit with edge tracks. Channel one and Channel 8, 16, 12 24. The edges of the tape get easily damaged. This causes problems with tracking the high frequencies consistently. So you don't necessarily want to put high-frequency rich content on those edge tracks. The edge tracks do better with more mid and low frequency content. As you won't hear the high frequencies fading in and out as the tape runs. So no solo instruments nor vocalists on those edge tracks either.
As to multi-track azimuth adjustments. You have a number of choices.
When you are calibrating playback. You can take tracks 1 8 or 2 7, into a scope or summed together into a voltmeter. Tweak the azimuth screw adjustment, for maximum output. But there could also be other errors of the azimuth, due to gap scatter with the other channels. In that case, I would recommend that you take channels one through four and summing those together. Then take tracks five through eight and sum those together. Then take both of those into your vertical and horizontal inputs on a scope. And just for peak output. This will give you the average between all channels.
In some cases, it's occasionally more helpful to have a pink noise tape, to use for your azimuth adjustments. The reason for that is that, 10 kHz by itself can look right (if incorrectly adjusted). But the azimuth can be so far off that the other frequencies are all over the place. Even if it looks good at 10 kHz. Pink noise is all frequencies simultaneously. So you can get your azimuth closer.
We also had those over at Scully/Ampro. But then we also had fast sweep calibration tapes from 500 Hz to 20,000 Hz. These sounded bizarre and just as obnoxious as SMPTE. While it could get us tighter azimuth adjustment while also looking at frequency response on a scope that had a calibrated clear plastic frequency response template to put over the scope. Still allowing us to get the average peak of the azimuth adjustment. I had more than one scope at my final test bench.. So I could do both azimuth and frequency response at the same time, to look for any anomalies. Along with distortion analyzers. Both THD and third harmonic distortion analyzers were on hand. THD to check the electronics. Third harmonic, to test record bias settings.
While we used high-end test equipment, at Scully. Most playback and record adjustments done in most studios, is simply done with the onboard VU meters on the machines. Now this is not as accurate but is good enough for rock 'n roll and government work. Sticklers wanted their test equipment. Average Joe's, just used the VU meters. One quarter or one half DB here and there, ain't no big whoop. It is to those with engineering OCD. Not me. Remember, NAB standards are ± 2 DB, 50-15,000 Hz. That's good enough. And these machines were better than that. So if using the VU? That's just fine. Remember, even the VU meters are not 100% accurate. Good enough for rock 'n roll. Good enough for Mozart.
Well... here's another reason why a lot of folks would drop the power supply off from the back of the deck plate. We would take it off then put it on the floor of the Cabinet. Doing so actually serves two useful purposes. While still allowing for the absolutely silent convection cooling, they've always used.
Plus it can also reduce whatever 60 Hz hum that exists in the system when the power supply is so close to the playback head cables and heads. It makes your machine just a tad quieter. And overall, things will run even cooler that way.
Mostly recording studios would do that. You wouldn't usually find that on broadcast station machines. They would leave the power supplies in place. Many were in vertical metal rack cabinets 5 feet up. And the cord on the power supply to the transport, wasn't that long. But on those Rus Lang studio cabinets, it was the perfect length. And you could still flip the transport on its built-in hinges.
So in many ways it was actually designed to have that done. For your option to leave it connected to the back of a transport deck plate. Nobody care how hot they got. We always had superduper shiver cold air-conditioning. And that's why they have such potent air-conditioning in both broadcast operations and recording studios. It's great in the winter time. You save on heating bills. There's nothing like snuggling up with a nice warm Scully and hot cocoa. AH
Honestly, no one likes fans in control rooms. Sure... other machines had fans. My MM-1200's had fans. I hated it! So here's the problem.
In the old days... we had our machines in the control room, with us and the mixing console. Eventually, they started moving the multitracked machines into a machine room, behind or next to the precious listening and mixing environment. Because not only did you have fans... you had tapes scraping against reel flanges. You heard the clunking and snapping of relays and solenoids. That was the multitracked music production environment where you wanted it as quiet as possible.
Jump into a commercial production facility and you need your machines right there with you. You're going to be sitting there, one with the machine, having an intimate time with that machine, editing tape for hours on end. Until you practically felt like you were married to it! And it was your bed partner! And frequently... it was. Sometimes it even looked like it was smoking a cigarette right along with you. And you want a fan?
It was good for me. Was it good for you?
Mx. Remy Ann David
It's been a long time since I have disassembled one of those DC servo capstan motors. Like 1980. Maybe 82?
As I recall... one of the first things you should do. You should carefully, gently, remove the infrared LED/LDR, tachometer sensor. Hold the small circuit board in place when removing the screws. So as not to have it touch, bump, scratch the tachometer disk.
From there... there really isn't anything else you can damage. Other than the clear plastic tachometer disk. Which is likely extremely fragile at this age. It could likely just fall apart by just being touched. Kind of like a very thin eggshell. An eggshell that you are trying to remove from a motor.
You'll take off the bottom plate on the motor to access the spring-loaded graphite wipers. You must also be very gentle with those. As is very easy to stretch and bend, the springs, abnormally. Those graphite wipers, as I recall, were originally about 3/4 inch in length. Yours might be down to less than 1/4 inch? The shorter they get with wear, the more intermittent they become until they completely fail.
You can clean that printed circuit stator, carefully with Q-tips and 91% isopropyl. Methyl alcohol, wood alcohol, I'd stay away from. Really it should be cleaned with Freon. But that's hardly available anymore. None of their replacements should be used. And no other solvents of any kind. Not even water.
Remember, Freon, was electrically inert. Things could be soaking, with Freon and wouldn't blow up when you turned on the power. This is not true nor applicable to any of the other replacement refrigerants. Most everything else, including alcohols, are electrically conductive. So thorough drying is absolutely necessary. No impatience.
The capstan shaft and the bearing/bearings can then also be easily removed. The bearings can be easily replaced. You can also have the capstan shaft re-sandblasted, to remove any shiny polishing from the tape. In fact, I think it's an easier motor to disassemble them the standard AC capstan motors?
The biggest problem used to occur, when someone reinstalled the LED/LDR, putting a little scratch into the clear plastic tachometer disk. This you need to avoid doing.
It's also possible that you can not have the printed circuit stator, completely perpendicular to the shaft. Carefully lock something down like the tip of a pencil, right near the outside edge of the printed circuit stator. Then spin the shaft, by hand. Making sure that the printed circuit stator, doesn't wobble.
There really isn't much more to that. That's shaft was only offered in that single diameter, for all speeds. Unlike the AC motors. Where the shaft was milled down for 3.75/7.5 IPS machines. Where the shaft was 50% larger in diameter for 15/30 IPS machines. Over the standard 7.5/15 IPS AC capstan motors by Ashland. Though I have seen a couple of Scully's with the same AC capstan motors as Ampex machines which used Bodine's. They just had different screw mounting holes tapped in. In fact, I think, some were made to fit both machines? As one was a three-point mount, for Scully's and the other a four-point Mount for the Ampex machines. Though they both use different connectors on the wires. As I recall? I've got all of these manuals but they are still packed away since my move to Austin, Texas.
If you want to remove the pins from Molex connectors? You need two different sized Molex pin extractors. One for the male. One for the females. The Molex nylon shell will melt very easily. So don't do that soldering to those Molex pins while they are still in the Molex connector shells. You'll regret it if you do. Not because I'll kick your ass. But because you will. Don't. A word to the wise. Molex pin extractors are not that expensive. They are easy to use and spring-loaded. None of us techs can't live without those pin extractors.
Jerking the take-up reel by hand and/or changing the speed. To make the capstan motor go into runaway. Really does not sound like a motor, an amplifier problem. Though it could be a TTL chip problem, on the circuit board? Perhaps a spike in a diode or capacitor is not properly blocking or filtering? Causing the logic in the servo to go crazy? But it stays with the motor?
So you go down to your store. Or you call up Digi-Key, Newark Electronics, et al. Then you order yourself a new set of male female pins. With a pair of Molex pin extractors. You cut the old wires and pins off. Then you can solder new pins onto the wires. Once they cool. They are easily inserted, by hand, into the Molex shell. You might have trouble with some of the pins or sleeves and accidentally damage them, installing them. In which case, you'll use your Molex pin extractor. You'll unsolder that pin. And solder on a new one.
So I'm not just talking about changing out the pins for the motor wiring Molex. I'm talking about the one you have to plug into, on the chassis, as well.
We know the reliability of these Molex pins, has little left to be desired. Gold ones. No problem. Standard alloys. All the problems. And these pins have been subjected to years and years of airborne air pollution and particulate matter. That gets glued on, cemented on, to these lousy alloy pins. And that kind of intermittency is the dirge of these Molex connectors. The old Jones style ones... not so much so. Those are relatively easy to clean and restore. You remember those MCI machines. You mentioned it yourself. You know these connectors were the scourge of those machines. Consider yourself lucky, as to how reliable they actually were for the Scully's. Probably because these were plugs and jacks. And not circuit boards on motherboards?
Fixing those MCI JH-110's was sort of like cracking your knuckles. Most of the time, when the machine started to freak out and do weird things. You would simply shut it off. Tilt the transport up. Then just start crunching those circuit boards up and down on the motherboards. One at a time. Just like cracking your knuckles. And voilà! It works again until next week... on... THE OUTER LIMITS.
We now return the control of your television back to you until next week... when the control voice says, this is The Outer Limits. We control the mail Molex pins. We control the female Molex pins. We can insert them in a haphazard way. You can try this with a soft focus, without your glasses. Or you can insert them with crystal clarity, if you put your glasses on first. You've entered THE TWILIGHT ZONE. Whoops... wrong TV show! So take a journey with me through the Molex maize. Since you'll be traveling through another dimension.
Do do, do do, do do, do do
Dave, Ha ha, glad you liked the bit of levity.
I never get upset no matter how many times people ask me the same questions, over and over again. It's how you play it safe. A smart person does that. These machines can be quite quirky. So knowing as much about these machines as one can. That's a good thing.
It's great to hear you got the other motor drive amplifier working. Those are darling Darlington's. There's plenty on the 280 B transport TTL logic card. They energize the solenoids. Tape lifters. Pinch roller. Breaks.
A word of caution regarding those Darlington's. Not sure if you're using the original GE's?. There was a serious intrinsic problem with those.
This was one of the worst problems with the B series machines. This did the most damage to those machines. Gulp. Here goes.
One of the reasons I was hired at Scully was because 30 machines were purchased and shipped to the South Korean Broadcast Network. While they are given a 24 hour burn in before shipping and before final testing. They would test fine. But those 30 flamed out, within their first week of operation. It caused an international incident where the South Korean Government contacted the US State Department. John Cyr, then VP of Ampro/Scully and an electrical engineer, was sent to South Korea. Numerous circuit boards had to be replaced as those Darlington's literally burned holes right through the TTL logic cards. Some could be repaired while others had to be replaced. Once they were repaired, the South Korean Broadcast Network, dumped all the machines. Here's what happened:
When Dictaphone owned Scully, they glued on a piece of nonconductive cardboard to the transport control chassis lid. These Darlington's were not passing enough current to require the heatsink designed to be affixed to the Darlington aluminum heatsink tab. This was also the connection to the collector of the Darlington. And if that aluminum heatsink tab were to touch the metal of the transport control chassis lid. It would cause the solenoids to energize. Whoops. So the cardboard prevented that from happening. I'm lazy so... I never thought much about just removing the transport control lid, altogether. You couldn't see the guts within the studio cabinet or even in a rack. It's not like it's shielding it from any spurious electromagnetic interference.
When Ampro took over. They didn't want to be bothered by gluing on the nonconductive cardboard on the inside of the transport control chassis lid. The lid that you would remove to gain access to the circuit board and the other support circuitry along with the pushbuttons for the transport. So to prevent the possibility of the heat sink collector tab from connecting to the transport control chassis lid. They got the bright idea to simply bend that tab over. I would have done the same thing. That's where the trouble was that caused those machines to flame out.
The company electrical engineer (not John Cyr who is also an electrical engineer) Michael Circus had instructed everybody to bend those tabs over. Since Alex Myers didn't want to use anymore cardboard shielding.
In my troubleshooting, I discovered those transistors would go into thermal runaway when the tab on the Darlington transistors were bent over. They would most definitely work for a while, correctly. It was my hypothesis that the transistor substrate, within the epoxy package, somehow was getting stressed from the bending. Michael said this couldn't happen. I told him it was happening! We certainly did not see eye to eye. So I called up GE semi conductor division. The guys at GE verified my hypothesis. So I said we should put the cardboard back on inside the transport control lid. Only to be vetoed on that, by Raphael Alexander Myers. Instead, Michael instructed everyone to take a pair of diagonal cutters and simply snip off the aluminum collector heatsink tab. I thought this also to be a bad idea.
In the end, I was right again. Even having those tabs cut off, caused the Darlington's to go into thermal runaway, once again. I told him it must be the substantial transient snap that was doing the same thing to the Darlington that happened when the tab, was bent over. Again Michael said that couldn't happen. Really? Again I put another call to GE semiconductor division. Yup. I'm right again. GE told us we needed special diagonal cutters that had a small wire like shock absorber, added to these special diagonal cutters. To cut down on the transient spike that traveled down the aluminum heatsink collector tab. Damaging the transistor substrate. So enough were purchased, to give to all of the first through, test technicians. Problem solved! I must admit... this is one of the most peculiar problems I've ever encountered. Who would have thunk?
Much of my personal education in this field, came from me, simply by calling the manufacturers. At a time when long distance calls weren't cheap and no one had unlimited long-distance calling like we see today. But if ya don't go to school.. Like I didn't. That's a great cheap education. You get the straight scoop when you talk to the company's that design and build the parts, equipment, products. I mean who needs a dumb college professor, instructing you, who didn't build these contraptions?
If any of your Darlington's have that tab bent over? Do not bend them back if they are still working. But also check and make sure they are not getting overly hot to the touch so as to burn your finger. I guess those Darlington's, even damaged, would continue to function. Unfortunately they would get so hot as to damage the circuit board without just opening and failing. Or even shorting out. So this is a serious cautionary piece of information for any of those folks out there that have any of the B series Scully's. It seems like such an innocuous thing to do, that likely other engineers that had to maintain these machines. They might bend over the tabs? Even if it wasn't done at the factory. And especially if that piece of cardboard came unglued from the lid. Which it did at times. Especially with age. Holy cow! Whoops. I mean, I would even have personally done it. Though I never did, to other B machines. Glad I didn't LOL. Probably because I'm not OCD? Ya think?
That runaway problem... have you tried swapping the motors between the two machines? Swapping them. Not just the motor drive amplifiers. The two track motor in the four track machine. The four track motor in the two track machine. And does it still runaway that way, related to that motor? There could be wiring intermittency's on that two track machine. The problem could stay with the two track machine? Even if it has the four track motor. After all, you don't even need to pull tape to check that. I'm just trying to troubleshoot through the process of elimination.
Replacing the electrolytic capacitors in all machines of this vintage, any reasonable audio equipment, most often than not, brings it back to like new operational condition. Wherever ya see electrolytic capacitors. Not just the motor drive amplifier but the audio electronics and any that you find in the transport control chassis, power supplies, et al..
No duty cycle adjustment pot? HUH? I don't remember any of those motor drive amplifiers without the duty cycle adjustment? That's an important adjustment. It varies from motor drive amplifier to motor drive amplifier. Also depending upon, the motor. There are variations in the printed circuit stators. Which is why they're usually should be a duty cycle adjustment, somewhere? So that's really strange. Do you have the schematic to that one? And what do they have in place of that duty cycle adjustment pot? A fixed resistor value? Hey... maybe it came from an Ampex 440 machine? Though, I don't remember those looking quite the same, between the Ampex and the Scully's? And those would also have a duty cycle adjustment. Are there different part numbers on the circuit boards? Any extra prefixes or suffixes? This has a lot to do with the torque and the consistency to the DC servo capstan motor. And these are adjustments that could be necessary, over time. Parts age, just like we do. Especially when you're talking about a servo.
Before you work on the capstan motor, I would first remove it from the deck plate. Put it on a surface where it will not, roll around. And then very carefully first remove the LED/LDR tachometer sensor, very very carefully. So the answer to your question is no, I wouldn't remove the bottom plate first. I mean ya can. I just wouldn't. Since the wipers did need to be changed from time to time. I would remove that sensor, first. Even though you don't have to. If by chance somehow you slip? You don't want to risk that clear tachometer disk to get any kind of scratch, from that sensor.
Sounds like no need to mess with the bearings. Slight wear to the finish of the capstan motor is no big deal as you surmised. Only when it gets polished by the tape until it gets shiny. Then you want to have it sandblasted.
Now here's the cool thing about the shiny worn capstan shafts. When it gets shiny, it has removed the bit of the surface texturing. Making the circumference ever so slightly smaller. So that sandblasted or not. The tape will now run imperceptibly slower. With the AC capstan motors. You're stuck with that. With the DC servo capstan motors. You can tweak the motor drive amplifier to bring it back up to the proper speed. When you are using a reference calibration tape for speed, from a crystal controlled, extremely accurate, oscillator. And one hell of an accurate fast, frequency counter, or other wow/flutter meter. As I recall those are 3750 Hz. And as I recall triangle wave and not sinewave? It sounds kind of buzzy. Not a nice sound. Drive ya crazy. Nasty on the ears.
Remember when cleaning the printed circuit stator, to also be very gentle. Light on the touch. You'll never get rid of the entire graphite stain on the printed circuit stator. So no OCD style cleaning of that. Just the top layer of grunge is all that's necessary.
Again also be ultra careful, not to stress the springs, of the graphite wipers. Very easy to do. Extremely delicate. Repeat. Extremely delicate. And if that happens? You might not care for the results.
Okay I just realized it's 6:41 AM and I haven't gone to sleep yet. What the...??? Time sure flies by when you're trying to refurbish and troubleshoot an antique audio recorder. Thank you for trying to help un senile myself.
I think this is me?
When these machines were first designed, they were built with GE germanium transistors in a metal can TO-3 case. They have the GE logo right on the top of the transistor. Some are silver in color. Some are black in color but still with the metal T0-3 can.
When the silicon transistors were developed. They found them to be lower in noise. Which was a real big deal back then. These are identifiable as little black epoxy packs. And are about half the size of the older GE germanium TO-3 cans. About 1/8 inch in diameter as opposed to about 1/4 inch in diameter for the TO-3, germanium's.
Germanium transistors have a different voltage drop than the silicon transistors. So the biasing resister for that transistor has to be changed with a different value. But that's it. It's a simple swap out of the transistor and the resister. I cannot recall the two different values of the resisters from memory as I am having a 60-year-old moment. I'm about 15 miles away from my Bridgeport, germanium machine and cards along with the manuals. So, in the next couple of days. I'll try to access my germanium playback cards. Then we can try and double check, the value of all of the resisters. Of course the 280 manuals, should indicate the transistor numbers so that one can ascertain, what transistor you have. And then whether it has the proper biasing resistor value.
There are many people out there, much like yourself. They are fairly knowledgeable analog recording enthusiasts. But they may not know that those resisters have to be the correct one. Which could be the possible problem? Some people took their silicon-based cards. Knowing the characteristics of the germanium is to have a warmer low-end and a beautiful smooth high-end. Albeit, it's noisier. Swapping out the silicon transistors for the germanium's? Or vice versa. Some took the germanium transistors. Knowing they were noisier. And swapped them out for the silicon transistors. And in either case... didn't know to change the biasing resister for the proper transistor. And while the machine will still work. It most certainly won't work right. The precise symptoms? Even though I've run across that, years ago. I can't remember what the actual symptoms were?
The printed specifications of the Scully's frequency response, exceeds that of the NAB standard of ± 2 DB 50-15,000 Hz. Now while you should see plenty of low-end, down to 30 Hz. It would not be unusual to find that 2 DB down or 2 DB up.
Speaking of the electrolytic capacitors. They can be thought of as something akin to a rechargeable battery. While those can last a long time. We all pretty much know that they will only be accurate and useful, for about 10 years. Beyond that. While still usable. Response could vary greatly. If the electrolytic capacitors have not yet been used and are new. And have been sitting in your spare parts box for 10 years or so? Even though they are new. They may not be the right value.
In a similar scenario. I have the 8 KEPEX-1 downward expander/gates. When I acquired them used (they are from the very late 1960s, earliest of 1970s). While they were still operational. No way were they working correctly. So I had to replace all of the electrolytic capacitors. And it made these things work like new again. And they continue to work that way for about 15 years. But after that... ugh... I'm going to have to replace all of those electrolytic capacitors if I expect to use those, as I always have, once again. The only thing I enjoy about replacing those capacitors? Is that my KEPEX-1's, will again work like new. I really can't use them the way they currently are. There are's extremely inconsistent from each other. Even though all of the capacitors replaced, what were the correct ones and all at the same time from new stock. So it's rather fascinating to see how different each one of these eight now functions or dysfunctions. I have found that no two of those function the same way. Which I find to be an interesting curiosity. Why would each one be different in its functioning? Everything and everyone ages differently from each other.
So these electrolytic capacitors are a little like buying a bunch of bananas. Some of those bananas will ripen faster than the others of the same bunch. Yet they all grew together. And every electrolytic capacitor, manufactured by the numerous different companies that make them. They all sound different from each other. Even though the values might be the same. And that will greatly affect frequency response.
Sometimes the issues to these problems are completely counterintuitive. Some capacitors might have a warmer sound. While others have a clearer more open sound. Some might have a better sweeter high-frequency response. While others don't quite sound the same in the high-end. There are just so many variables here. So you might want to try a different brand, until you find the one that suits your needs? And within a single brand. They frequently have electrolytic capacitors that have similar but slightly different voltage and heat ratings. That was a famous mistake made by Siemens/Neve, with their VR consoles. A big whoops. They used to low a heat rating. So while they worked for a while. They all started to leak after a short period of time. They did monumental damage to those Neve V/VR series consoles. And even after being repaired, refurbished, restored. They never quite worked the same way again. Ouch! Because of that. A lot of studios dumped their $150,000/$250,000 Neve consoles.
We'll all help you get to the bottom of this. As we are all putting our heads together. Though... I think the gap in my head is getting a little too wide these days? I seem to be further away from my memories than I can remember? So maybe it's time to change my head? Recently I did. I got a haircut.
I'm a little PITHED.
Ahhh. So you've got one of those? Not to worry.
Some multitrack recorders. From the various manufacturers. Some had smaller than tape width wide, pinch rollers. It was felt that, it could take a better bite out of the tape to the capstan motor shaft. That when the pinch roller rubber started to age and/or wear. The full width types could go slightly concave. Letting the tape virtually slip between the pinch roller and the capstan motor shaft.
So by making it narrower than the width of the tape itself. It couldn't do that. It would also result in less tape skew. And maintain better alignment of the tape path.
Not that most machines don't have wider pinch rollers than the tape width. Most do. But you'll be replacing those pinch rollers, before the narrower ones.
So you not only get more consistent performance over a longer period of time with less maintenance. It also puts off having to shell out more dollars for new ones. So it was a win-win to make them that way. It just looks strange. It feels strange. It looks stupid. Which I think is why it fell out of favor for doing that?
So you're good. You're fine. You shouldn't worry. It's all good.
What you do have to be conscious of. Is the actual alignment of the pinch roller perpendicularly. Now this is not necessarily an adjustable item. Though, on some machines, you can and you have to. Ampex MM-1200 would be a good example of one of those that can be slightly skewed if needed. The Scully's, not so much so. Which is why they went to, a single center bearing. This would allow the pinch roller to align itself to the capstan motor shaft much better. Resulting in less tape skew. But if you have pinch rollers with bearings at the top and bottom? Sometimes one would have to slightly try and bend them. If you are having issues with tape skew due to improper perpendicularly. Which is also another reason why in later B series machines. That additional capstan motor shaft perpendicularly adjustment screws were added. Along with those self aligning pinch rollers. For an even more superb consistent tape path. Through proper alignment and adjustment procedures.
Yes, most 1/4 inch and 1/2 inch machines have a wider pinch rollers than the tape. If you wanted to do that with 1/4 inch tape? You would likely need a 1/8 inch wide pinch roller. Now how stupid would that look? Yeah... totally stupid. Like you shouldn't even be in the business LOL. And we don't want to present that image now do we?
So there ya go. Your questions answered. It's not wrong. It's smart. In a stupid kind of way. And it works. It works well.
I even remember back in 1973. When I came up on an Ampex MM-1000-8. It had a three-quarter inch wide pinch roller for 1 inch wide tape. Which was my first experience with that. When I was only 17.
If you think that's bonkers? Have you ever seen the capstan motor shafts or pinch rollers on 3M machines? No?
Now this is totally bonkers. But it also works. It's what that very compact ISO loop design that 3M used. And that was both a capstan motor shaft that was slotted. And a pair of slotted pinch rollers. Now this looks totally bonkers. The idea here was. The tape is being pulled out. Faster than it is being fed in. Which creates the tension across the heads. The tension is determined by the slots. And you have to have the heights properly adjusted. That is critical. And when your pinch rollers starts to wear out. You have to replace both. Those are fabulous machines. But they can also require more frequent pinch roller replacements. In order to maintain the integrity of the tape path and travel. Along with tape to head contact.
So thank your lucky stars. You're not dealing with one of those. You've got it easy. You own a Scully.
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