Do those "CCCP" tubes look like these? They are Soviet-era, rocket-logo, Voshkod-made tubes. They last forever, but take a LONG time to break in. You may want to keep them around. They are mil-spec 6N1P tubes — they are very good!Got my BUF yesterday. Have swapped the stock "cccp" badged tube (Sovtek) with an NOS Telefunken 6922 ($400). That helped. IMMENSELY! Running a ChiFi Rotel CD 14 MKII into a Schitt Gungnir 2 into the BUF. Sounding so much less SS. :^)

You need to give them time to break in. That is true with a majority of Soviet-era mil-spec tubes. These things were originally designed for high-G jet and missile avionics. Not audio. It can take a long time to lose that veiled, constipated sound.That be them, Booch! I thought them a little veiled compared to the Tele. IMO.
Cody
Well, if all else fails, they make great XMAS tree ornaments!Constipated! That's how it sounded, though, I did like the tubeyishnous of the 6N1P.![]()
I have one in my BUF and four in my Stjarna- excellent tubes ! Took about 150 hours to break-in in the Stjarna. The one in the Buf is still in progress, but getting better all the time.Do those "CCCP" tubes look like these? They are Soviet-era, rocket-logo, Voshkod-made tubes. They last forever, but take a LONG time to break in. You may want to keep them around. They are mil-spec 6N1P tubes — they are very good!
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Those tubes can last longer than any solid-state device in the circuit. The Russians made them for ICBM use, amongst other avionic applications. Tough is putting it mildly.I have one in my BUF and four in my Stjarna- excellent tubes ! Took about 150 hours to break-in in the Stjarna. The one in the Buf is still in progress, but getting better all the time.
Maybe leave the BUFF on all night for a couple days? The 6P14P-EV's labeled Sovtek I put in my ST-35 didn't sound all that great at first. But after I put some hours on them they opened up and I really like them now. Same for some of the octal and 9 pin Soviet era driver tubes I've bought in the past.Do those "CCCP" tubes look like these? They are Soviet-era, rocket-logo, Voshkod-made tubes. They last forever, but take a LONG time to break in. You may want to keep them around. They are mil-spec 6N1P tubes — they are very good!
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My favorite looking speakers are Vandersteen Quatros.
Maybe leave the BUFF on all night for a couple days? The 6P14P-EV's labeled Sovtek I put in my ST-35 didn't sound all that great at first. But after I put some hours on them they opened up and I really like them now. Same for some of the octal and 9 pin Soviet era driver tubes I've bought in the past.
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The Buf unit failed? Or the tube?Well, mine failed after three days of use. Probably par for a box full of Chinese electronics.