In the picture are three of the stereo 880s which is the Crimson top end power amp.
The Crimson 710 preamp is at the upper right in the photo. The Crimson 710 Preamplifier (crimsonelectronics.com)
Design Outline
The main audio PCB was designed and produced by myself for Crimson. The power supply PCBs, the control PCBs and the engineering design and drawings were all done by my son Eliot Powell. He is UK based and he has a Physics degree. He has earned Chartered Engineer status doing his design work for the electronics in mass spectrometers. He also writes the code for the microcontollers being used. He works at the limit of the resolution of the very best measuring equipment.
The stereo amplifier consists of four boxes. One pair contain the primary power transformer supplies which include soft start. The second pair contain another power supply stage and the audio PCB and cooling. A hefty interlink carries the lower voltage DC interconnect power as well as control lines. A dump circuit prevents hot plugging surges. The power amp can be configered with a DC coupled input.