16Dec2019 09:36 AM
StevePPosts: 8 
I'd like to work out the correct impedance for a new volume pot in my system. I am running two Quad 303 amps, Dada upgraded. The source is a laptop & DAC, so no preamp, just a passive volume pot I put in as a temporary solution a decade or two back. It works OK but doesn't take the volume down low enough, meaning I have to use the Windows audio stack to keep it in check. I'd prefer to bypass this and send the full signal out, unmolested by Microsoft engineers. The numbers I know are: 2 x Quad 303 amp, input impedance of 22 ohms each (one for each L&R channel). I don't now if the Dada upgrade alters the imput impedance at all or whether using the amps like this effectively halves the 22 ohm figure? DAC output impedance 5 or 50 ohms (I have two to choose from) I'm looking at a choice of a 10k, 50k or 250k log potentiometer. Anyone good at maths? Many thanks!

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