Which Headphone Amp for Sennheiser 600?

I want to buy a used headphone amp to drive the 600, any suggestions?

Showing 2 responses by mcne

I am also using the X-CANSv2 with my 600's. Can you explain to me about upgrading the tubes in the X-CANS?
Thanks Rmml. It is easy to open up. I just didn't know which tubes to upgrade to. Thank you.