Obviously, the simplest alternative is to have different volume controls for the analog and digital section.
Using different volume controls for digital and analog inputs is the
opposite of keeping things simple.
Using a single control for both, which indicates the current volume setting at a glance, is the simplest solution.
Agreed, it's the simplest from an intuitive point of view. I was just suggesting what I think is the technically simplest non-ideal solution from an ergonomical point of view to what I find to be a non-ideal volume control design for the reasons mentioned above.
The other one would be to have an analog stepped attenuator combined with a LCD screen, just like on the Lavry DA11.
The Lavry DA11 is a digital-only device, yet it uses an analog volume control.
Digital volume control in a modern DAC should offer better performance than analog control.
I think that would be the best solution from an operational point of view since it would allow one to do exactly what the current implementation does, without all its drawbacks, with precise steps as a bonus, and the possibility to have separate memories for digital and analog inputs as an option (which could be useful if your analog source's level is widely different from the level at which you usually listen to digital inputs). Perhaps Benchmark judged that this wasn't worth the added cost, but as far as I'm concerned their current solution is 40% of the reasons I decided not to keep mine past the 30 days return policy and I suppose I'd have gladly payed a few more bucks to avoid it.
Or perhaps it was not a cost reason, but a quality one. The custom motorized ALPS pot is not a cheap solution either.
Or maybe they simply don't like the interface. I would much rather have a pot than a switch to control volume.
The problem with Benchmark's system IMHO is that they tried to have the pot directly control analog attenuation which is the source of all its volume control problems. Basically, Benchmark's solution is to have a digital input for digital volume control, and an analog input for analog volume control, all in one knob that's motorised (because that's the only way to be able to remote-control an analog input), while I think they should have gone for a digital only input + LCD screen to control both a stepped analog volume control and the digital volume control for each respective kind of sources. The Lavry DA11's volume control input is DIGITAL, yet its volume control itself is analog, that's why you can remote-control its analog volume control without the need for a motor. Of course I'm certainly not asking for its awful metallic lever to be copied, it's rubbish. But you seem to like volume pots, and it's a perfectly feasible digital input interface (only that it would have to be a 360° wheel). The Invicta's got one for example.
Now the question is : will a stepped analog volume control for the analog inputs compromise IQ in comparison to an ALPS pot ? This I can't answer, but I don't really see why it should. In fact stepped analog controls are widely seen as preferable to continuous pots, and digitally controlled analog volume controls even more so since they aren't prone to tear and wear anyway. Of course, the 32bit digital volume control would remain for the digital inputs, it's better.
The other problem is that the ESS 32 bits digital volume control is finely grained in 0.5 dB steps, and I'm not sure it's economically feasible to have such a finely grained analog stepped volume control. In which case Benchmark could have several solutions, like a different number of steps between digital and analog volume controls (and for example change the LCD colour to clearly tell you that you're in the analog or digital volume control domain) and a different memory between digital and analog inputs (which IMHO makes sense anyway since your analog inputs might have a different level than your digital inputs), or "rounded" steps to the nearest dB for the analog volume control (basically, if you've set the volume at -57.5 for digital inputs, it would go to -58 for the analog volume control). I don't know. I'm not saying that's going to be easy, but I'm saying that I'm not the only one who despise the DAC2's current volume control and that a redesign would greatly improve the DAC.