Re: reading from cassette

[mjmahon@aol.com (Michael J. Mahon)]

desiv asked:

>"Michael J. Mahon" <mjmahon@aol.com> wrote in message
>20030831130314.18024.00000126@mb-m24.aol.com">news:20030831130314.18024.00000126@mb-m24.aol.com...
>> Vince Briel replied:
>>
>> >"Michael J. Mahon" <mjmahon@aol.com> wrote in message
>> >20030830202938.18419.00000131@mb-m13.aol.com">news:20030830202938.18419.00000131@mb-m13.aol.com...
>> >> Vince Briel wrote:
>> >>
>> >> >Hey all, I have a tape that I want to read and I'm having probs
>getting
>> >it
>> >> >to read on my II+. Is there an emulator I can try and use that loads
>> >> >cassette sounds? Actually I'm trying to load from an MP3.
>> >>
>> >> Check your levels.
>> >>
>> >> The Apple II cassette input was meant to be an "external speaker"
>> >> output level from a cassette recorder.  It is low impedance and a
>> >> couple of volts.
>> >
>> >I may have one of those old cassette players. I just thought transferring
>> >back to cassette would degrade the sound too much. I'll give it a try.
>I've
>> >tried adjusting sound levels and I've gotten close, some of the info
>loaded,
>> >it just errored out. I must have tried 30 different levels. Thanks for
>the
>> >help.
>>
>> The problem may be noise picked up through the grounds.  Most
>> cassette players are very well isolated from the AC line, since they
>> either run on batteries or with a tranformer-coupled wall wart.  A PC
>> is not nearly so well isolated, and the ground is likely to contain
>> noise from the switching power supply.
>>
>> Using a cassette deck as an intermediary may provide the isolation
>> needed to reduce ground noise significantly, and may solve your
>> reliability problem.
>
>So, why would the recording of the MP3 to the tape (intermediary) not have
>the noise from the PC's ground?
>
>(I am not an electronics guy, so that's a real question.  I'm not trying to
>be funny..)
>
>Is that a type of noise that the Apple would pick up but a recording usually
>doesn't???

No, but the cassette recorder, because it is better isolated from the AC
line, is less likely to result in noise current flowing in the ground wire
connecting it to either of the two computers.

-michael

Check out amazing quality sound for 8-bit Apples on my
Home page:  http://members.aol.com/MJMahon/