Rane RPM 26z - Upgrade?

[meex]

Hi, I recently had a chance to try Rane RPM 26z instead of my DCX2496 in my 3 way setup (hypex UCD amps) and I think it is nice step up with Rane in terms of sound clarity and transparency (high frequencies have more air)..
One thing I don't like is the self noise on the Rane, which is much more obvious than on the DCX..
My question is, how to minimize that noise on Rane? Should I change Op Amps or what to do first (op amps are jrc 4580)? Wheter is worth it? If answer is YES, what is the best "value for money" replacement op amps instead jrc4580?

Or another way is to modify DCX, but I don't want to spend a fortune for that mod's, just want to know what should change first to see improvements in sound claritym, and how many things I should change for really improvement?

Thanks in advance..

 

[Richidoo]

See attached schematic for Rane RPM26z 😀

There is A LOT of stuff between DAC and output jack, much more than DCX, so I decided not to attempt upgrade. I think just swapping buffer opamps will not make a big difference, but I like ST Micro MC33079, it sounds better than most at unity, imo. Whatever opamp you swap, check for oscillation.
P.S... My RPM26z is for sale, if anyone's interested. 😉

Gary Pimm wrote a nice article about modding DCX2496, including schematic of the output stage, but his site pimmlabs.com is gone now.

Wayback Machine:
https://web.archive.org/web/20131024013259/http://pimmlabs.com/web/behringer.htm

 

[meex]

I forgot to mention that my chain is full digital until last stage (DAC of the processor), so I'm not using analog input stage at all.
Correct me if I'm wrong, the chain is:
Computer - Soundcard via USB
Soundcard - Behringer SRC2496 via optical spdif (SRC is just SPDIF/AES converter)
Behringer SRC2496 - Rane rpm26z (or DCX2496) - via AES/Ebu...

Thanks.