Ok I know this is quite an old thread but still very current for us Croft owners.
Any thoughts on the Series 7 input valve ECC83. Anyone tried different valves in this position with better results rather than the standard JJ's?
For what its worth I run a GE JAN 5751 in this position which works well and reduces gain a little although I would like to try a NOS GE 5 star 5751 1960's tube if I can get hold of one. The JAN GE is a bit lean and etched.
Got a really nice NOS Tesla ECC83 Gold Pin 32 coming to try in the Series 7 this week so will report back once I have tried it.
Main system : VPI Scout 1.1 / JMW 9T / 2M Black / Croft 25R+ / Croft 7 / Heco Celan GT 702
Second System : Goldring Lenco GL75 / AT95EX / Pioneer SX590 / Spendor SP2