Since the publication of our previous general-purpose remote volume control project (June 2002), a number of readers have requested a comparable unit with digital, rather than analog, attenuation. In other words, they want to dispense with the potentiometer, citing the short operational life and poor channel-to-channel tracking of these mechanical components.

For those that haven’t seen the earlier project, a dual-gang motorised potentiometer was driven by a microcontroller to selectively attenuate the incoming audio signal. The advantage of this approach is simplicity and (depending on the pot used) relatively low cost.

We used this method again in the Studio Series Preamplifier Control Module (April 2006), where we showed how it is possible to achieve both reliability and high performance using a more expensive motorised potentiometer. Nevertheless, we con-tinued to receive requests for a digitally attenuated version – so here it is! Now you’ve no excuse not to do away with that noisy old pot and upgrade to this state-of-the-art digitally controlled module – which should never wear out!