Under the hood of the DSD-S reveals a very clean layout of five horizontal and one vertical board plus the custom Eltrans P-core power transformer.

Amongst other bits, the digital input board features the XMOS USB transceiver and a pair of quality Crystek 'femto' clocks plus a third smaller clock.

The digital processor board sports the expected quad array of vintage Cirrus Logic chips and a Xilinx Spartan FPGA for various custom-coded housekeeping duties.

The analog board sports four defaced solid-state relays as part of the hybrid attenuator, with two more for output muting between the heat sinks of the vintage Toshiba Mosfets. Two opamps perform DC servo control to maintain DC offset for the output buffer below 0.5mV. There are also two Lundahl amorphous-core coupling transformers.

It all looks perfectly straightforward and sensibly put together.