ARC of the past compared to today

[daveyf]

As many of you know, I am a HUGE fan of the older ARC D series...particularly the D70's and the D115 and of course, the M100's. As an owner of a D70Mk2, I believe it is one of WZJ's masterpieces and would not trade it for most any other low-medium powered tube amp. Today we have the newer Ref series, the closest to the D70 Mk2 being the Ref 75 and SE version. These new amps are certainly great sounding, but are they really that much better than the amps from what I...and many others, consider the 'golden age' of ARC,--The D series!

How far have we come in circuit design and overall SQ from that 'golden age'??
BTW, please don't jump to conclusions unless you have actually heard both series..or an earlier series not mentioned.