Crosspost from
Mass Kobo thread:
Alright! The mod of Mass Kobo is completed, moreover.. documented on YouTube
My friend (audio reviewer and fresh YouTuber) has done an amazing job and now the op-amps are swappable in the MK 428/475 - those two “models” are exactly the same, just different usb connector. If you could give Michal’s channel some love, will be highly appreciated
For start we’ve immediately put Sparkos SS3602 in preamp stage and Muses02 in output stage. Mass Kobo has a new sound to it - I’d say it’s become meatier, namely bass is stronger and tighter and the signature has slightly more body. As for soundstage, details, etc. I’ll have to wait to receive stock JRC5532 back to compare more directly (it was 2 weeks break in between hearing MK). I will be writing conclusions after those direct comparisons with stock and some other opamps
Here are some photos when I took it apart. Easy enough for anyone, but complex enough to be satisfying as well!