Gold or Platinum Grade of Tubes for BAT Preamp.


Hi, all. I am awaiting delivery of my BAT VK-33. I’m going to replace the 6 stock EH 6922s with the NOS Rocket Logo 6H23-EB, which is a direct replacement for the 6922. My tube vendor has gold grade or platinum grade (which is about $15 more per tube than the gold grade). Tolerances for matched gold grade are 15-20%, while the platinum tolerances are 10% or less. Given that these are small signal tubes, is the tighter tolerance of the platinium grade worth the $$? Is the BAT hard on tubes, thereby requiring the more expensive ones? Thanks for your help.
rlb61

Showing 5 responses by petg60

@rlb61 Victor knows his design better than anybody, 6h30 is another tube that works perfectly in BAT's circuit. So you have plenty of choices to experiment with.
Listen your VK33 first with the supplied 6922EH and then get some 6h30 to check which family of tube type you prefer.

G
6n23p-ev is not the same tube as 6n23p, or e88cc/6922, though interchangable it behaves more like an e188cc with less dynamics, due to much lower cathode resistance that will draw too much current in a 6922 circuit, if you want that.
Life expectancy same as 6n23p.
I would use platinum matched in a phono stage and gold in line.

G
Voskhods (Rocket logo) made only 6n23p, direct replacement for e88cc6922, and the preferable ones to seek are 1974-1979 period (earlier the better).
The EV version is a different kind of tube, that can stand harder circuit environment, and was made by Reflektor and not so desirable sonically compared to a 6n23p.
I may be wrong but i never came across or seen any Voskhods with the EV designation.
That is my experience with them.

G

@petg60 ... Victor from BAT told me that the
6H30 is a direct replacement for the 6922.
You got me confused.

G