The Passion 8M from Audio Synthesis is probably the best passive preamp ever manufactured. It sounds very transparent, presuming a good match with the power amplifier. The Passion 8M uses the best parts available, such as WBT connectors, Vishay precision ...
Former Reference DAC from Audio Synthesis with the renowed and sought after Ultra Analog D20400A DAC chips. This unit still performs at a very high level. Price for this classic is now 550 euro.