On constant impedance passive attenuators

should be _linear_ potentiometers, there, it is perhaps not true for other tapers?

Think of a single stage Kelvin Varley divider without the pot on the end; just a resistor to satisfy the divider. I guess you could do it with a couple of ganged pots, the shaft of the second pot offset by the proper angle to satisfy the KV ratio? A kluged arramgement for sure, but would seem to satisy your requirements. Coupling the shafts together with some gears would also be a possibility. Or a specially constructed pot with two wipers inside.

Dave M

That's a truth, but for practical purposes, a fixed attenuator of 1000 ohms and 10.101 ohms has 10 ohms output impedance, +1%/-0% impedance tolerance, and can be appended to any non-ideal attenuator such as the author describes.

Yes, it also attenuates by a factor of a hundred, but... gain is cheap.

Definately not true for other tapers, especially if arbitrary tapers are allowed.

eg: use three potentiometers to form a pi or tee network, one will, I think, need a reciprocal taper.