That was one of the reasons I went with Hybrid stuff. I currently have PS Audio. The BHK preamp that uses two 12AU7’s and the mono blocks are currently using 6922’s. All of which can be affordable and last a fairly long time.
My downstairs mono blocks use 4, 6HB5’s in each and they starting to get expensive to replace. I’m still using an ARC SP9 MKll Hybrid preamp with them and it uses 6922’s also.
