Replacement tube recommendations

[corndog71]

So it sounds like one of my 4P1L tubes is not doing so good.  I've been meaning to pick up some replacements but it looks like they're all in Russia.  Any recommendations?

[Grainger49]

I get good service, but not fast delivery, from a number of old USSR sellers.  I have used these more than once and would not hesitate to recommend them:

Alexer1
KWTubes
Alex550

[mcandmar]

I got nice early 60's vintage sets from tubeprofi,

http://www.ebay.co.uk/itm/NOS-matched-pair-4P1L-directly-heated-output-pentode-f-tube-amplifier-same-Year-/361091484100?pt=LH_DefaultDomain_0&hash=item5412bac9c4

[corndog71]

I got nice early 60's vintage sets from tubeprofi,

http://www.ebay.co.uk/itm/NOS-matched-pair-4P1L-directly-heated-output-pentode-f-tube-amplifier-same-Year-/361091484100?pt=LH_DefaultDomain_0&hash=item5412bac9c4

I ordered 3 pairs and got them faster than expected!  They all have the winged "C" logo stamped into the metal base. Original Svetlana?

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi576.photobucket.com%2Falbums%2Fss207%2Fcorndog642%2FBottlehead%2520Smash%2FCF54122E-C060-4F84-81BC-FA2F4DEFC136_zpssja2xo3e.jpg&hash=6bfebf200b97abec4326b8656936f912768675af)

[mcandmar]

Yup, the "Winged C" logo as people refer to it.

[corndog71]

I listened to the first pair last night.  Wow!  Great soundstage and powerful bass.  Can't wait to try the others.

[mcandmar]

What year of manufacture is stamped on them?      People claim the best of them are the early 60's vintage, and of the three sets i have the two early 60's pairs sound better to my ears.  Its as though they have better extension on the high and low end of the spectrum.

[corndog71]

That first pair was stamped 62. I also have a pair of 63 and 71.