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Bob Latino wrote:Replace the choke with the Triode version. It is a better choke than the original Dynaco C-354 choke and won't leak that brown goo.
As to the DIYtube ST-70 board vs. the VTA driver board. The DIYTube board (AFAIK) is only sold as a board which means they give you a parts list when you buy the board and you have to source the parts on your own. With the VTA driver board you may EITHER buy the board alone or purchase your VTA driver board with a complete parts set. The DIYtube board also uses (AFAIK) at least in part the original Dynaco wirewound bias pots. The VTA has its own "on board" bias system and does not use any part of the original Dynaco bias system.
Other than that, the circuits of both boards are similar. The DIYtube board uses a 12AX7 voltage amplifier tube and two 12AU7 phase splitter/inverter tubes while the VTA driver board uses three 12AU7 type tubes for both voltage amplification and phase splitter/inversion.
tubes4hifi wrote:also if it's an original Dynaco from the 60s the output tubes are likely Mullards labeled Dynaco, they say, "made in Great Britain"
and are worth alot of $$$ same with the rectifier tube - I just saw a Mullard 5AR4 in a Dynaco last week,
I've also got one in an original Heathkit amp.