Atmos cassette output

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Vyper68
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Atmos cassette output

Post by Vyper68 »

Hi,
Does anyone have any idea of how to make the cassette output from an Atmos louder? When I save a tape it is barely audible. I can save onto my laptop using Audacity but it is very quiet compared to my other 8-Bits.
Looking at the schematic there only seem to be a couple of resistors in between the 6522 and the cassette output so is there any way to boost the output?
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Dbug
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Re: Atmos cassette output

Post by Dbug »

Don't quote me on that, probably check the service manual instead - but I believe I've read somewhere that some machines have the wrong value for one of the resistor, and that ends up weakening the signal way too much.
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Re: Atmos cassette output

Post by Vyper68 »

Thanks DBug, will have a look inside my Atmos this afternoon...
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iss
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Re: Atmos cassette output

Post by iss »

According to the schematics the expected max. voltage should be around: 5V*(1/23) = 217mV (peak-to-peak) which is really low for standard "Line level". You can do some experiments - replacing R13 (1k) with bigger value (i.e. 4k7, 10k, etc.) and see the effect. At-least there is no risk to try. :)
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Re: Atmos cassette output

Post by Vyper68 »

Fitting a 4.7K resistor has made the output louder but not a massive amount. Tape is still not very loud but the signal recorded in Audacity on my laptop is visibly stronger. Maybe I need to swap out this Rockwell 6522A with a Synertek model down the line, I might stick a 10K in and try again :D
The other resistor was 22K so it was the correct value.
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