It's a tube preamp, not that complicated to work on, you probably would get more for your money with a smaller tech like bigkidz.
ARC REF 6 upgraded by ARC.
I have an ARC REF 6 I bought in 2019. I just upgraded my amp to the ARC REF 750. I now want to upgrade my REF 6. Does ARC still do this I now I should call them to see but it’s Fri night and probably wolnt be opened til Monday. And I really would like to know before that.