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.


----- 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
> Quality tape transfers -- even from hard-to-play tapes. 

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