Do you mean the “ Dark “ upgrade ? Although the specific tubes are not listed, the upgrades are listed on their Upgrades page. They state the signal tubes are upgraded but don’t specify brand. On other models that use the same tubes, they are usually nos Tekefunken and RCA. The JJ’s their stuff ships with to me are poor sounding. I’d suggest contacting them by email and verifying or ask one of their distributors. Happy Hunting , Mike B.
Tube Complement in Cronus Black ?
Has anyone here ordered a Cronus Black? or do you know which tubes are part of the upgrade package?