Thanks for the link Jono. I did not know of it.
My guess these are Shuguang tubes, AKA Sino tubes.
http://thetubestore.com/sino.html
I use the EL34's in my hifi amps, as well as the 6SN7. I have also used 12AX7 and 7025 and coke bottle shape 6L6GC's. I think I fitted 4 in Alan's twin. Maybe he can report the sound?
As far as I can see, they are as good as anything else. I have read that they are virtually indestructable. The 6L6GC's can withstand 500V on the plates - and the amp cranked wide open. They are great for experimenting or budget projects, as well as OEM products.
