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Re: Apple II preamplifier

Simon D. Williams wrote:

On Thu, 8 Dec 2005, Michael J. Mahon wrote:



Alex Freed wrote:


Wow! How many solutions for a non-problem!

There is no need for an amplifier for a simple reason that the
tape output is driven by a full TTL signal. Almost 5 volts.
The reason the signal is weak at the jack is because of 2 resistors
forming a divider.

-------------R------------------->
                      |
                      R
                      |
                     ___
Cut the lower one and enjoy full 5 volts. Or replace with say 4-5 K resistor to get line level. 

Of course this will work to connect Cassette Out to Cassette In, but
at the expense of modifying the main board.  If both machines are your
own, and you don't care about custimizing, go for it.  But perhaps
he wants a "cable" he can use to connect to others' machines...



Probably an inline amp would be more practical. I don't plan on mating my
Apples to anyone else's, but it would be easier for switching machines.

Out of curiosity, would the output mod make tape saves impossible, or
would the tape deck's auto level control be able to adjust appropriately?


It would *way* overdrive the microphone input, or even most line
level inputs.  To preserve cassette functionality, the 100 ohm
resistor should be switched.

-michael

Music synthesis for 8-bit Apple II's!
Home page:  http://members.aol.com/MJMahon/

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