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Yes the Tascam uses the felt pad's friction but it also has a little known
sophisticated magnetic clutch/brake on the supply reel for controlled back
tension. It's electronically servo controlled, the only such system I'm
aware of in a cassette machine. So the two systems work together. That's
why I said the Tascam is still partially dependent on the felt pad.
Also in the Tascam the felt pad perfoms another role in forcing the tape to
describe a slightly "M" shaped path across the record and play heads,
"wrapping" the tape around each head's face. Whereas in the Naks there is no
"M" path. The tape travels in a straight line between the record and play
heads, whose faces are angled optimally for this. So with the Naks the felt
pad is not needed for that "M" role either.
Tim
----- Original Message -----
From: "Richard L. Hess" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, July 01, 2017 12:07 AM
Subject: Re: [ARSCLIST] Cassette repair question
> While the pressure pad lifter (may I call it that) is a great feature of
> the Naks, it is only part of the story. What enables the pressure pad
> lifter to work is the fact that the tape tension is controlled by the two
> capstans, whereas it sounds as if the Tascam 122's are still using
> friction to generate the back tension.
>
> I recall my third tape recorder (and my first "real" stereo machine), a
> Tandberg 74B, had an arrangement similar to what Tim describes below. I
> found that unsatisfactory. My next machine was a ReVox A77 and I never
> looked back.
>
> I don't know how Tandberg cassette machines generate back tension at the
> play head.
>
> Cheers,
>
> Richard
>
>
> On 2017-06-29 8:19 PM, Tim Gillett wrote:
>> I've serviced Tascam 122 MkII/MkIII's since the early 90's. They're an
>> interesting design in that the play head has a good long life, because
>> in common with most Naks, the felt pressure pad doesnt press against it!
>> But unlike the Naks the pad is not pushed away. The Tascam design
>> displaces the play head a little to the right of the pressure pad so that
>> the pad mostly presses the tape against the record head and a small metal
>> plate between the two heads. The friction creates back tension for good
>> tape contact with the play head.
>>
>> But courtesy of the felt pads, the record head and metal plate wear a
>> lot faster than the play head and before too long the head assembly needs
>> attention, even though the play head itself may still be in excellent
>> condition. With the Naks there isnt this accellerated and uneven head
>> wear. So being still partially dependent on the felt pad, the Tascams
>> although fine machines still have a weakness in this department in my
>> view.
>>
>> Tim Gillett.
>> Perth,
>> Western Australia
>>
>
> --
> Richard L. Hess email: [log in to unmask]
> Aurora, Ontario, Canada 647 479 2800
> http://www.richardhess.com/tape/contact.htm
> Quality tape transfers -- even from hard-to-play tapes.
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