I'll use the right to "document whatever" to make a little advertisement of my personal web page, documenting the development of my 304tl amp as well as it's (partial) financing source. no, there is no new forum there )
You won't go far wrong with copper gm70. Shame I only have a pair, have plenty of Graphite but I don't value their sound much. When you hear better valves you go right off the ones you arrived there from.
have you published somewhere on the web the results of the blind test, you presented once on GM70 board? I'd link there. If not, we could publish them on 304tl pages as a separate subpage.
Besides if you are interested in some NOS Cu GM70 I might be able to help (apologies for that advertising stuff).
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