Tube recommendations


Hi all
The phono stage within my pre currently uses these 3 stock tubes - Sovtek ECC83, Electro Harmonix ECC81 & ECC88 (I think it's Tung Sol).
As I'm new to tubes which tubes would you recommend to be a significant  upgrade?

Thanks 
Rich

128x128infection
@chakster Thanks. Yes I've noticed they can cost about $500 each.
I'll speak with Andy, I suspect he can suggest some excellent cheaper alternatives.



InfectionThe ECC83 tube is the same as 12ax7 tube. I recommrnd telefunken 12ax7's if you can find them . Huge upgrade over sto ck sovi et ecc83's which came with my phono stage.Are you sure the third tube is Ecc88 or is it E88cc?the ECC88 is a 6922 tube type. Same here i recommend tekefunken or my favorite,  Siemens.
@tzh21y Thanks for the suggestion. 

@nsp - the number on the tube is 6H23 & underneath that is 9202.