6h23P-EB vs 6922 in the input stage of the Wolcott or other tube amplifiers

Many years ago, I asked a service technician about the 6N23P for my 6922 preamp. Here’s his response.

I’m glad you asked me because the 6N23P-EV (in our alphabet) is not the one to get. The 6922 drop-in replacement is the straight-up 6N23P. The EV versions have too-low cathode resistance that will draw too much current in a 6922 circuit and lead to a lack of headroom that compromises dynamics.

The regular version is dead-on. Many people get it wrong and think the EV is better, which is true in the case of 6P14P (EL84 power pentode), but is not for the 6922 replacement.

Since you’re asking about an amp, not a preamp, it might be different.

I have a Modwright balanced output analog upgrade to my Oppo 205. I rolled rolled Telefunken 6DJ8’s into it and it was a big upgrade from the Electro Harmonix it came with. Very warm and inviting luscious sound. I then rolled NOS 75 6n23P Silver Shields in and they are superb. They produce a fast, detailed yet musical timber. The soundstage is wide and deep. Absolutely superb if you prefer fast and detailed yet musical vs a warmer somewhat slower more forgiving lush sound. If you like warmer I’d go with NOS Telefunken 7308’s or 6922’s.

Good luck! 

Has anyone done an extensive study on the differences in the sounds of the Russian 6n23p-ev ‘s that are made at the different factories in Russia, and the time period in which they were made to be able to recommend which tubes are the best sounding. There is Lao a difference in the getters on the tubes, from a double getter, to a single getter, that looks like an upside down flying saucer.  What’s the difference in the sound of these differences?

hi , I will make this short and to the point . I have lots of experience 
with these Russian tubes . Stay away from the 6n23p-ev and the 6h23n-eb. don't bother with any of the russian 6922 Electro Harmonix either .
The tube you want is the 6n23p or the 6h23n Voskhod 1975. It is the best sounding . the 1976 , 1974 ,73, 72 sound pretty good also . But clearly the 1975 single wire getter post (SWGP ) Rocket logo on the glass and the upside down flying saucer is the one to have . They are a pretty rugged tube also .You can find a nice pair on ebay for under 100.00 .  Let me say again--- I know what I am talking about .
1975 Voskhod (SWGP ) Rocket logo on the glass (although I have seen some without rocket logo ) most have them.
one other thing---there is a Reflektor 6n23p and a 6h23n also . They are not rockets . Some people like those instead . I found that they sound good , but just a little thin sounding to me I prefer the Rockets
 Hope that helps
  Good luck--Steve