Re: Help on MIC-Output ZX81
Posted: Thu Jun 03, 2021 3:43 pm
Also as Mark has previously pointed out, the output from the 81 is so low that the amplification level required is very large.
In my experience with audio work something like a good guitar pick with an output of 50-100 mv requires at least two stages of pre amplification for a decent usable signal of low noise so I cannot even guess how much pre-amplification would be needed for such a low signal as provided by the 81 mic output so as to drive the input of a 74LS14.
In my experience with audio work something like a good guitar pick with an output of 50-100 mv requires at least two stages of pre amplification for a decent usable signal of low noise so I cannot even guess how much pre-amplification would be needed for such a low signal as provided by the 81 mic output so as to drive the input of a 74LS14.