Originally Posted by Sugano-san
That's where you're wrong again -- the Opamps in the RKV do much more than correct bias current. As I said, I am not an audio engineer, but Helmut is. If his English were a little better, I am sure he could express with more clarity than I why changing the Opamps influences the RKV's sound so much. But then again, I don't think I did such an awful job in the first place.
In any event, it was my RKV on which the Opamps were changed, and it was the designer and manufacturer of the RKV who performed this modification.
Before I sent my RKV back to Helmut, we discussed the project and its different aspects in length over the phone and by mail.
It was Helmut who said that from his point of view changing the Opamps was the single most promising modification out of the ones that were performed. And it was Helmut again who was right. The dfference is huge. I hardly recognized my RKV when I got it back. And it was Helmut and me (i.e., not you) who did the before/after listening. So we should know.
This just goes to show that one ounce of practice is worth more than one ton of theory.
So my remarks stands: I am using the OPA 637 in my Supermacro and in my RKV, in both cases with excellent results.
I'm gonna ask you a simple question: to change OPAmps in the RKV make the same difference as changing an OPAmp in the PPA or any other amp, in which they are inside the signal path, for example like going from the OPA637 to AD8610...??? If yes, I stand corrected.....and please end of the discussion, the OPAms in the RKV are not used for an audio application, the difference could be audible of course, any change in one amp affects the sopund we all know that, but not as big as in the case of an OPAmp based amp...period....