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Thread: Tascam 424 Mk1 Service Manual required

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    Tascam 424 Mk1 Service Manual required

    Hi Does anyone have a Tascam 424 Mk1 service (repair) manual?
    I would like a hard copy, disc or email and will happily pay for same.
    Mickey from Australia

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    Actually a copy of the schematic would get me out of trouble!
    Mickey from Australia

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    Supporting Member The Dude's Avatar
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    Have you tried to contact Tascam directly? It's been quite a while, but I have gotten service manuals from them in the past. Otherwise, this is all I could find on the web- not free.

    https://www.analogalley.com/osccart/...oducts_id=1709

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    Master Destroyer nosaj's Avatar
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    Quote Originally Posted by Mickey View Post
    Actually a copy of the schematic would get me out of trouble!
    Mickey from Australia
    Can't find one online but what seems to be the problem?

    nosaj

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    [QUOTE=nosaj;554330]Can't find one online but what seems to be the problem?

    No great problem, fitted the motor and all seems OK although I think it is recording/playing a little fast. Thought I would look at the schematic and see if all is as it should be.
    I always like to have as much information on my repairs as possible, don't like working in the dark.
    BTW I am willing to pay for information so if anyone can supply me with appropriate info I will gladly pay any costs etc.
    Mickey

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    Lifetime Member Enzo's Avatar
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    You have mentioned pay, but pay isn't the issue. We generally post up anything we have.

    The motor and transport operate at one speed. It could be the wrong speed, but whatever speed it decides on, it has no idea if it is recording or playing back. SO whatever you record should come back out at the right speed. The problem occurs when you try to use the same tapes on some other cassette deck. If the two machines are no matched for speed, the tapes will never sync.

    I use a prerecorded cassette meant for wow and flutter testing, but it is a steady 3000Hz across the tape. I put it in play and adjust the speed for 3000Hz on a freq counter. A poor man's adjustment: find some prerecorded tape or record a tape on a trusted deck, then play it on this one and adjust the speed so the notes tune the same.

    I forget this one, but some of the TASCAM decks operated at twice speed. SImple for my 3000Hz tape, just adjust for 6000Hz on my counter.

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    Hi, thanks for your replies. Have you any idea at what speed the tape travels compared to a normal cassette? It's been a long time since I worked on cassette tape recorders and although I remember the electronics I'm a little rusty on the mechanics. I have a dual beam CRO, frequency counter as well as a audio frequency generator so checking the speed for variation shouldn't be a problem.
    Looking at the 424 again this afternoon I did notice that sometimes the head assembly and tape drive hesitate to engage, hopefully this will only be a minor issue, I'll be i touch if need be. Mickey

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    Lifetime Member Enzo's Avatar
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    It either runs at normal cassette speed, which I think is 1-7/8 ips. Or it runs at twice that. SOme models have a button to select hi or lo speed.

    The gear wheels have grooves or cams the mechanism follows, so when the heads cycle up or down it is all about those gears. ANy little dirt or grit in the teeth can bind it up. An eyebrow hair that falls in there while you work...seriously. Clean the gears.

    Also rubber must be healthy. If the main belt is a little stretched it won't grip and so and bind in the mech might cause the belt to slip rather than power the gear around. Likewise idler tires must be fresh rubber.

    REmember, whatever tape you use to measure speed, it must be recorded elsewhere.

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    Don't forget the joker g1's Avatar
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    That model has a switch for normal (4.8cm/sec) or high (9.5cm/sec) speed.
    There are 2 trim pots, one for normal, and one for high speed.
    You need to adjust with pitch control set to 0 (middle). Like Enzo said, the reference tape must be pre-recorded or made on a machine that has been calibrated.
    If you have a prerecorded music tape, and you know they used concert pitch tuning, you can probably tweak it by ear on the normal speed. The double speed setting will be exactly twice the frequency.
    So if you had a pre-recorded (factory) music tape and you knew they were tuned to concert pitch, a guitar passage with an open A string would be 110Hz and on high speed it would be 220Hz.

    Here's the schematic of the speed control board, R3 is normal speed trimmer, R2 is high speed.

    https://music-electronics-forum.com/...2&d=1447123215

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    Hi,
    I have a scanned 424 Service Manual if you still need it.

    PM me with your email address and I can send it to you. It's 10Mb so it's right on the limit of most email systems but if you mailbox doesn't accept it I can find another way.

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