[triode12]

I don't believe the 40th Anniversary will be inferior in sonics to the Ref10 when the circuit boards are identical in both the pre and power units (down to the spaces provided for the larger Teflon caps in the 40th Anniversary). The only difference I could see were the coupling caps. In the 40th Anniversary, it was proprietary White Teflon caps (apparently prone to failure but any units in circulation would have failed by now and been changed) and in the Ref10, ARC uses the TRT Gold Stealth caps which are not Teflon but a hybrid cap of sorts -the material used is a TRT trade secret. The difference in sound would be marginal if any and would be due to the different coupling caps used. 40th Anniversary internals on the left, Ref10 on the right.