Janszen electroacoustics, Электростатические колонки

Ответы:
1) Switching amps, yes, using both PWM and PPM (pulse position modulation) which is I think unique, and creates a smoother result than pure PWM with less residual ripple, thus needing less filtering and giving faster slew rate for a given switching rate. There are two in each speaker. The crossover is digital -- straight wire to the drivers. 2) The plinths are hard maple -- heavy and solid. The latest batch, however, is "Russian Birch" plywood, used because of a misunderstanding with our painter, who seemed to indicate it would be easier to paint. No drawbacks compared to maple -- similarly heavy and even more solid -- other than finding out after paying about double the usual amount for painting that it is actually harder to paint. 3) The amplifier and its power supply are on one PCB with appropriate slotting etc. to isolate functional blocks, and the DSP and input preamp are on another board.
4) The DSP is not field programmable.
For programming, there is an RS-485 header under the nomenclature label, it requires a special cable and converters, and teh software is written by Italians with limited grasp of UI design and incomplete documentation.