Teac/Tascam 80-8 deck help please

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notbananas

New Member
I just picked up another Teac-Tascam 80-8 deck and 48 1/2" tapes (Ampex, AGFA, Maxell, etc.) for $100. The heads look like it's never been used since the studio converted to all digital a long time ago. This is my second 80-8 deck.

The first one I have works like a dream. I aligned it with MRL (Magnetic Reference Laboratory) tape (cost me $150 for the 1/2" version @15ips) and aligned the heads and calibrated all 8 plug in boards for the Ampex 409 tape using a Tektronix dual trace scope, a Leader audio function generator, a digital frequency counter (to adjust speed) and a Leader RMS voltmeter and Fluke digital RMS voltmeter.

The only problem with this new deck is the capstan motor was not turning. Opening up the deck, I discovered this one has a different capstan motor than the one I have now and what the tech manual shows. It appears to be a much smaller motor with a pc board attached to it and a cable going to the back of the deck with a connector at the end. There are no other connections to this motor, so the only way it can run is with some sort of external power supply and control box.

This is totally weird because the other deck is identical to this one except for the capstan motor.

Asking the studio if they have any other pieces for the deck, obviously they didn't.

So as great of a deal this was, if nothing else but for the tapes, I hate to toss the deck because without the schematic for this deck or the control box that goes with it, it will become a salvage deck for parts.

Any help, even guesses, would be appreciated.

Teac/Tascam 80-8 deck:
teac-tascam-80-8-a.JPG





New capstan motor (note pc board attached to it and black cable going to back of deck):

new-capstan1.jpg





Here is the connector direct from the pc board to back of deck:

new-capstan5.jpg





Old deck capstan motor:

old-capstan1.jpg



old-capstan2.jpg
 
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It's a DC motor and the old, original motor is AC.

Someone (or Teac) took a DC motor (and it's driver board) from another model and adapted it to this deck. Perhaps for the option of variable speed. Trick will be to find the model the motor and especially the driver board came from. Once you find the model with the same driver board, you can just duplicate the power supply from that model.

Also, remove the driver board and post photos of it. Front and rear. Get any part #s off it.

If Teac did the mod, there may be a manual supplement for it that would have the wiring diagram.
 
You are correct, the old one is driven directly off the power transformer, so it is an AC motor. This one is a 24VDC motor. I also think you are correct about the speed control because there are two trimpots on the pc board: "Normal" and "Var1" which means the speed is adjustable on this deck and not adjustable on the older one.

But why would it be an external power supply/control box?

Now all I have to do is to find the power supply/control unit or the schematic so I can build one.

front of pc board:

capstan-pc-1.jpg




capstan-pc-2.jpg



DC motor:

capstan-dc-motor.jpg
 
It's completely broken. It'll never work again. I'll properly dispose of the machine (and those tapes) for you. My address is 200 Ros.....

Just kidding. What a score! That motor almost looks like a beefed up version of the capstan motor in my A-640 cassette deck.
 
Contact Teac and give them the board # (60505121) and see if they can search their data base to link it to a model #. Once you get a model #, then you are good to go. Order the schematic/service manual for that model and you will know what power supply you need for the motor driver board.

Also ask them if that was a special Teac version of that deck. Send them the photos. Does it look like a factory install or does it look jury-rigged?

parts@teac.com
 
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I seem to recall the 80-8 came with a variable speed option, with external controller. Maybe this could be the case here. The motor looks a lot like the DC motor in a A-3440. I suppose contacting Teac is the best option at this point.
 
As an aside, I purchased Mr. Theopolis' DVD-set last year - it's quite entertaining as he goes through the evolution of tape-recording. He has some really neat stuff. I highly recommend the DVD or online version - very cool.

He normally doesn't put up any of the good stuff for sale, however, and his current crop supports that reality. Can you say "J-U-N-Q-U-E?"
 
I know what deck that motor and controller are from, 'cause I have one! It comes from a A-6600. If you don't mind having the capstan motor turn all the time when the deck is on, all you should need to connect to the board is a
DC supply. The A-6600 is a bi-directional deck and the motor can reverse, so there is another board that controls the direction. You don't need that. I'll check my manual and see what you need.
 
Here's the schematic of the motor drive circuit. What you need to do is connect pins 1,2 and 3 to the speed switch, 12 is 24V, 13 is ground. Looking at the schematic it is obvious the motor does not reverse, and now I remember there are 2 capstans, the reverse one turns in the opposite direction. So you don't have to deal with motor direction.

TEACA-6600CapstanMotorDrive.jpg
 
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This motor is prone to the bearings drying up, so take it out of the metal case and oil both bearings.
 
tapetech said:
Turns out you are correct. Here is the 80-8 variable speed box for sale.

http://reel2reeltexas.com/vinSaleTapeRec.html

Notbananas: You might send the photos of the vari-speed unit to person that sold you the deck. May jog his memory.
Click to expand...

Wow! Thanks for all you guy's help, especially tapetech. This is exactly the box I was looking for! I checked the socket pins and the socket key and it matches the 80-8 cable pinout exactly and the label on the box said "To 80-8" at the socket!

It was still available, and I just bought it and paid with Paypal, so it should be on the way Monday.

I'm curious why have a separate box for pitch control when many of the other decks I have (Otari 5050, Tascam 34B, etc.) have it built in to the deck?
 
notbananas said:
Wow! Thanks for all you guy's help, especially tapetech. This is exactly the box I was looking for! I checked the socket pins and the socket key and it matches the 80-8 cable pinout exactly and the label on the box said "To 80-8" at the socket!

It was still available, and I just bought it and paid with Paypal, so it should be on the way Monday.

I'm curious why have a separate box for pitch control when many of the other decks I have (Otari 5050, Tascam 34B, etc.) have it built in to the deck?
Click to expand...

I'm guessing it was an afterthought for that model and they didn't have room inside for the extra circuitry or the extra DC power supplies needed. Remember the original AC motor ran off the AC, so it didn't need DC power supplies. Pretty lucky to fine the box for sale.
 
Why is it necessary to have a pitch control and to go to this extreme (redesign, external box, etc.) to provide one? If the capstan is rotating at the precise speed to provide the selected ips, then it's not necessary. If the recorded tape is off pitch, how would one know what the right pitch is when playing it back?

I have many professionally recorded tapes made for radio stations that have a tone recorded on the lead in, but without a frequency counter (which I have and use with the MRL alignment tape & scope), there's no way to adjust the pitch to be correct.
 
notbananas said:
Why is it necessary to have a pitch control and to go to this extreme (redesign, external box, etc.) to provide one? If the capstan is rotating at the precise speed to provide the selected ips, then it's not necessary. If the recorded tape is off pitch, how would one know what the right pitch is when playing it back?

I have many professionally recorded tapes made for radio stations that have a tone recorded on the lead in, but without a frequency counter (which I have and use with the MRL alignment tape & scope), there's no way to adjust the pitch to be correct.
Click to expand...
First, the simple line-voltage driven capstan motor motor in the 80-8 gives you only one fixed speed. There are many variables that can change speed (belt tightness, bearing friction, pinch roller pressure, tape tension, etc.), so often the actual speed is close to correct, but not spot-on perfect. The only way to adjust the speed is to install a different diameter capstan motor pulley. With a DC motor, you have total control over the speed and can set the speed to be spot-on correct.

Also, if someone sends you a tape that was recorded slightly off speed and you want to add a new track, say, you can adjust the vari-speed to get back in tune with the studio instruments. Or if someone sends you a tape with perfect speed , but the instruments were not tuned exactly to 440A, then you can use the vari-speed to get the music back to 440A. You could also use the vari-speed to change the key of a song if one desired to do so.
 
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I just received the Teac 80-8 varible speed control box VS-88. It works perfect!

When I opened the case of the VS-88, the only electronics in it is a standard linear power supply (bridge rectifier and an electrolytic cap) to supply power to the capstan board inside the 80-8 deck.

The only other components in the VS-88 were passive (pitch adjust potentiometer, pitch adjust on-off switch and the power on-off switch). It has a standard A/C 3-wire plug. The odd part is the capstan motor and it's electronics, which are mounted inside the 80-8 deck, are totally isolated and separate from the rest of the deck.

As soon as I have time, I will trace the circuit of this box and see what it would take to reproduce it.

Christmas being so close, I also purchased a gift to myself from the same website which is the download version of the history of open reel decks by manufacturer. Amazing to think that magnetic tape recording only lasted about 50 years from start to end. I guess we just keep the technology going, similar to what we are doing with tube stereo electronics which is finally making a comeback.
 
notbananas said:
Christmas being so close, I also purchased a gift to myself from the same website which is the download version of the history of open reel decks by manufacturer.
Click to expand...

I have the DVD set (there is an updated version now) from about a year ago - it is a great wealth of information.
 
Here's the VSK-88 installation manual. It includes detailed instructions and schematics for the servo board and VS-88 Controller. I bought a 8-80 deck that was missing the controller and was able to replicate the controller with a 24VDC power supply, a SPDT switch, a 1K pot and a few resistors.
 

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