Flg2001, where are you getting your information about the DA60 operating in Class A/B?
Jadis has always advertised the DA30 and DA60 as operating in pure Class A. The power consumption figures are listed as being the same as their respective counterparts, the DA50S and DA88S. I can't speak to the DA60 or DA88S in terms of bias with any authority as I've not measured them on the bench, but from getting my Defy DA30 together, it's Class A. Indeed, I was told by a fellow I correspond with at the factory that the Defy DA30 that I own (built in 1990), which is the original Jadis integrated, is biased the most heavily into Class A of all of the integrated iterations, and more reflective of earlier Jadis philosophy if you know what I mean. Overall, the DA60 seems to be mostly of the same mind (there surely are differences, circuitwise, some of which more meaningful than others), apart from doubling the tube count and upping the transformers considerably.
I'm not necessarily refuting you, but I was told the newer generation represents some tidy improvements in both circuit and implementation (for example, a more elegant and efficient selector control) as well as details which provide more optimization with the focus on using KT88 (and 6550/KT90) output tubes, whereas the older variety run very well (I would say optimally) with EL34/6CA7/KT77 tube types. The newer amps supposedly also run the smaller tubes, but for whatever reason, the larger ones are recommended. Anyway, I'm told these things result in what they like to call a more "black and white", as opposed to "grey", kind of sound - see my more clarity, detail, etc., and perhaps bit less romance and sweetness ala the general trend in high-end audio through the past decade. In general, as you said, more reflective of how Jadis thinking has evolved towards the current time.
Why do they offer both old and new product lines? Though I've asked several people, I've never gotten what I consider a good answer from anyone on that.
