Using ADCL or ADCR as a 4th control input?

[pharaohamps]

You guys are all going to hate me for asking all these dumb questions. Is there any reason I couldn't feed a control signal into ADCL or ADCR, like a 1K sine wave or something, and use ABSA to get its amplitude as a control signal? I know the inputs aren't DC coupled so I can't just use a pot, but if I needed another control signal, that seems like a pretty elegant way to do it. I gather from Keith's notes that you can use the outputs as control signals since they'll put out DC if you want 'em to. I was thinking about using DACL or DACR as a tempo indicator for the delay... You could even make it fade up and down with LFO0 or whatever, if you were doing a chorus or phaser, etc.

Matt Farrow

[frank]

Actually, you can use any input as a control signal. As the ADC and POTS are register mapped they can be read via RDAX, used as the coefficient in a MULX instruction, etc. So you should be able to read in an ADC input, find the amplitude of the signal and use it as a control function.

[lenham]

Frank (or anyone else with the answer),

Just to clarify, are the FV-1 main (audio) ADCs internally AC or DC coupled, i.e. do they have a hardwired high-pass filter?

I appreciate that in the standard application circuit they are externally AC-coupled because of their mid-rail biassing, but would like to know if, with a bit of ingenuity, they can be made to read DC directly.

Many thanks,

Steve L.

[frank]

Audio ADC's have an internal HP filter so you can't use a DC control signal on the ADC inputs.