Audio Horizons TP 2.0 Preamplifier

Clio09. That's interesting as well as confusing. In Markwatkiss's post above in referance to the 6H30P he says the mark after the 0 looks like an upside down u. My 6H30P-DR's have the same mark where the P should be. Looks similar to a lower case n to me. On the 6H23P-EB that I'm now holding in my hand, in place of the P is also this same mark. This is an origional equipment 6922 out of my Lamm 1.2 Ref. monos. So I'm just assuming that this mark is the letter P in Russian. I'm finding that the more I look into tubes the more that I need to learn.
Frank

Hi guys,just heard from Joseph,the Russian super tubes are not recommended for use in the TP 2.0 as it may cause over heating of the filament.Frank and Sherod,if we should ever meet the drinks are on me.
As Forest Gump would say,life is like a box of chocolates you never know what you're going to get.Anyone in the market for some rare 6H30's.

Frankg, if you go on eBay and do a search of 6N23P, some of the ads will have close up photos and you can see examples of the same alphabetical differences previously mentioned. Yes it is somewhat confusing, but the tubes are well worth seeking out. They are cheap and very consistent in quality. Make sure you seek out NOS, which for these tubes means prior to the break up of the Soviet Union when military standards for testing the tubes was more rigid.

Mark,
It's nice to see that you were able to find this info out before there was any damage to your preamp. I look forward to enjoying a fine drink with you some day.