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 $$? Is the BAT hard on tubes, thereby requiring the more expensive ones? Thanks for your help.
@noromance ... The $$ isn’t the issue. I just want to know whether the claimed difference in tolerance will be audible from a small signal tube. If it will, then I’ll gladly pay the extra.
You may not notice. However, if the tolerances deviate from the spec by too much, the tube itself may not have come off the line as well built as one closer to spec. That's assuming they're matched to that parameter and not just matched to each other. Even so, I'd go for the better tolerance at this level. My phono tubes are matched to 1% apparently.
@stereo5 ... the VK-33 appears to be the last of the current BAT preamps to use the 6922. The "SE" version uses the 6H30, and I think all other BAT preamps now are using the 6H30. The VK-33 has been discontinued recently, so I got a decent, discounted deal on a BNIB model and have the ability to tube roll.
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.
@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.
@petg60 ... the 6H30 will not work in the VK-33 as it is a 6922 based preamp. It will work in the SE version, which I didn't purchase, because I wanted the option to tube roll and am not a fan of the 6H30. Nonetheless, I have a wide variety of tubes with which to play.
So what's the story with the NOS Rocket Logo 6H23-EB? I'm curious because there tons of varieties of NOS 6922s and compatibles. There have been many articles and threads about the pros and cons on many of them. I've always had good luck with Amperex Bugle Boys (Holland) and I recall a number of folks raving about Tung Sol 7308s and others lusting for warm Mullards....but the 6H23-EB? Is that guy @EBM involved? If so, "jump on them asap". Cheers, Spencer
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.
@rushfan71 ... actually it was about $100, and all I wanted to know was whether the tighter tolerances were worth the extra scratch from an audible perspective. I’ve got plenty tied up in cables because I can hear the difference ... I don’t know whether that will hold true with tube tolerances. Nonetheless, I spent the extra dough. I find it fascinating that people in this hobby will spend money blindly on equipment without bothering to understand what, if any, sonic benefit they will derive.
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.
