I have now fitted my Nord NC500 monoblocks with the uprated boards and op amps.
I originally decided on the Burson V5 discrete op amps, but Nord also very kindly sent me the Sparkos to compare with them as well.
Fitting was quick and easy with the instructions provided but Nord- IQ will do it for you if you prefer.
I should add that inside the amplifiers are very neatly laid out and the new buffer boards seem to be very good quality.
With either op amp sound wise the treble is probably slightly more natural than before and overall the sound is fuller. Of the two the Sparkos gives more of a fuller warmer sound perhaps because it is class A.
I felt the bass seemed slightly deeper and more controlled with both op amps but there is not a lot in it.
Overall I do prefer the subtle changes that both these op amps give.
There is also slightly more detail than before I notice even more things in my recordings that I had not noticed before particulary with the Bursons.
Out of the two I prefer the Burson V5 because they just sound slightly more natural (accurate) on musical instruments but again there is not a lot between them.
Maybe because I like music as opposed to singing the Bursons suit me best.
The Sparkos in my system seemed a little too smooth on most of my recordings.
The Sparkos seem to suit singing, female vocals sound very good.
Obviously the rest of your system, room and the type of music you like may make a difference as to which is best for you.
The Bursons are brighter sounding than the Sparkos in my system and I do have a couple of Cds where I think if I listened for many hours I may get listening fatigue whereas the Sparkos would probably stop that. But the rest of my music sounds better to me with the Bursons. Perhaps I could make up some sort of switching arrangement betweem op amps.
So summing up my impressions over standard op amps:-
Sparkos much smoother,marginally better bass, more detailed
Burson marginally smoother, marginally better bass, more detailed, more accurate and detailed.
For the record the rest of my System is an Audiolab 8200CDQ with built in pre amp. And Troels Gravesen designed Illumina 66 floorstanders.
On the Audiolab I use the Optimum Transient filter.
The CD player will be replaced in a few months time with a Lakewest FDAC with built in CD slot.
With regard to the speakers I used a 1R5 resistor to the ring radiator tweeters thus they are not bright speakers having as Troels Gravesen calls it the BBC dip. On the other hand my room is quite bright as it has a laminate floor with just a rug between my listening posistion and the speakers.
I am giving you this information as it could explain why I felt the Sparkos was too smooth most of the time. But also I am 68 this month and my HF hearing may not be so good anymore.
