"For power amplifiers there are two I can recommend without hesitation. The first is the Crown Studio Reference, big and ugly, but does a very good job. The second is a bit trickier because it is the NuForce Ref9 V2 which I have modified with OPA2227 op amps instead of the stock NE5532. The tricky part is that the op amps are SMD type and covered with some nasty glue….. I know that NuForce are going to test the OPA2227 with them and I guess they will use these op amps in future versions of the SE amp..............."
Thanks for the info, Ted.
I'd heard about both, including the improvements Karsten heard with the op amp swap, but it was third- or fourth-hand info. I try to avoid making public recommendations unless my assessment was derived from (1) personal experience with the product in question or (2) direct communication with a trustworthy individual whose hearing I trust. Though you didn't make a recommendation, Karsten is most definitely trustworthy IMHO.
Let's hope the "
undisputed leader in switching-amplifier technology" will take Karsten's advice and make an OEM-level op amp change.
Since the Ref 9SE V2 is their statement product, and since Karsten arrived at his opinion after listening via some of the best, most advanced speakers in the world (Revelations with the works!
), the decision would seem of the no-brainer variety, but time will tell.
I'm not terribly optimistic, but I hope I'm wrong.
Personally, I'd be interested in knowing how the OPA2228 compares. I like the improved bandwidth (33MHz vs. 8MHz) and slew rate (11 V/us vs. 2.3 V/us) of the 2228, but we're talking about as much as a $10 (2227) to $20 (2228) increase per pair of amplifiers, and maybe NuForce believes it isn't worth it.
'Course, those prices are for a single, non-OEM purchase. I'm sure a company with NuForce's manufacturing capabilities could get a far better price than you or I.
In defense of Karsten; there are no official Nuforce current mods of V2amps; (so related to me Yesterday).
Rod
Hi Rod,
I believe most everyone realizes there are no "official" modifications for the V2, but the rumor I heard is that the amps were clearly better with the 2227 op amps. I'd hoped Karsten would chime in with a detailed accounting of his experiences and experiments, but I understand his hesitancy, what with being a NuForce dealer and all.
Even so, I wasn't in any way admonishing Karsten for not posting. I was merely expressing my desire to hear about his latest findings, that's all. It's been a while since we've heard from the Denmark Den of Auditory Excellence.
How do the different opamps change the sound? Is karsten using the se version?
mike
How do they change the sound? I don't know, but in some cases the sound can be improved - or worsened - a *LOT*!
And yes, Karsten has the latest Ref 9SE V2 amplifiers.
