I place this note to the opinion UNESCORecords anterior (2007). This power amplifier is a link that provides a spectacular amlioration when replacing a Quad 405 or a Quad 405-2. Its bargain price dropped to around 600 euros. Most of its electronic components are available on the market with significant amliorations. It is very sought-just as the market opportunity.
I could compare it with the Quad 909 and my subjective impression is very in favor of 606.