Path: utzoo!attcan!uunet!samsung!sdd.hp.com!zaphod.mps.ohio-state.edu!brutus.cs.uiuc.edu!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu!m.cs.uiuc.edu!irwin
From: irwin@m.cs.uiuc.edu
Newsgroups: sci.electronics
Subject: Re: My CD player is running slow! (
Message-ID: <21000085@m.cs.uiuc.edu>
Date: 5 Jun 90 21:07:00 GMT
References: <266@<6382>
Lines: 42
Nf-ID: #R:<6382:266:m.cs.uiuc.edu:21000085:000:1862
Nf-From: m.cs.uiuc.edu!irwin    Jun  5 16:07:00 1990


/* Written  7:33 pm  Jun  4, 1990 by chuck@umiami.miami.edu in m.cs.uiuc.edu:sci.electronics */
/* ---------- "Re: My CD player is running slow! (" ---------- */
In article <55024@microsoft.UUCP>, gordonl@microsoft.UUCP (Gordon LETWIN) 
writes:
> In article <6378.26693284@umiami.miami.edu>, chuck@umiami.miami.edu writes:
> 	Gordon Letwin


>							  I would rely on
>the pitch of a CD over the pitch of a tape deck any day, especially since 
>the tape speed varies over the length of the tape, and the fact that the CD 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>player is (supposed to be) accurate to 1/44100 of a second.

>I never thought this would be such a big thing... :-)
-- 
===========================================================================
>   Chuck Urwiler    University of Miami Music Engineering   Voice & Keys  
> chuck@umiami              | This space for rent...
> e1mvqi9z@umiamivm         | 
> chuck@umiami.miami.edu    |
> chuck@miavax.ir.miami.edu |
===========================================================================
/* End of text from m.cs.uiuc.edu:sci.electronics */

The tape speed should not vary over the length of the tape. The capstan
moves the tape through the deck or cassett player, not the supply/take-
up reels/spools. There is a slip mechanism on the shafts so that the
spool speeds vary from beginning to end of tape, as the diameter of
the amount of tape on the spool changes.

The capstan motor is governor driven on most lower cost units, with
an adjustment screw available through a small hole in the motor case.
On more expensive units, the motor is electronicly controlled, external
to the motor. The results is the same however. The capstan controls
the tape speed and it is constant throughout the length of the tape,
as it passes a given point (the heads).

Al Irwin
irwin@m.cs.uiuc.edu