Vacuum tube amplifiers can be a fascinating hobby

[cbsboyer]

I picked up a raft of Russian tubes (mostly 6N1P and 6N3P types) in a couple batches for my Vali 2+. They really work quite well in that amp. FYI the 6Н3П needs a 6922 to 5670 adapter, otherwise it's instaboom.

In the lot, I found a "B82П" tube with a 2 underneath, so I was very puzzled and did some digging. The only references I could find were either for a B82П with a 6 underneath, but that was a power tube, or someone saying "What is this thing?"

I have a small assortment of 6DJ8 and 5670 type tubes, so I did some comparisons and it is constructed identically to one of my older 6N3P tubes. So, I got brave and tried it out - yup it works perfectly.

So, from what little I've been able to find, it seems that I've got my hands on a very rare (at least in the west) clone of a Western Electric 396A tube. It appears to be between 71 and 75 years old because the Russians changed to the newer identifier system 1950, and the 396A tube was introduced in 1946, leaving a 4 year window.

Not a bad bit of afternoon entertainment from a $2 tube.

 

[12Bass]

Interesting to see people delve into decades-old tubes in the age of CPUs with billions of transistors. Bit of an audiophile myself, but haven't gone down the tube rabbit hole much other than some tube bass gear (like my Ampeg SVP-PRO). What sort of differences are you hearing between the various tubes?

 

[cbsboyer]

The Vali series amps are hybrid amps, so I'm told it does cover some of the differences between tubes, at least on low gain. On high gain it seems they designed the Vali 2+ to work the tube a bit to bring out the tube sound, and made the discrete driver section as transparent as possible to let the tube shine through.

What I'm finding is that new production tubes tend to be "flatter" or more linear. Kind of transistor-like I guess. Older tubes seem to have a bit more variation between them and subtly different characteristics between production years and types.

Personally, I'm finding that the old Soviet era 6N3P tubes really extend the bass response in my headphones without sacrificing the mids or highs (well, as high frequency as I'm still able to hear). I've got a new production JJ 6922 that is definitely a good tube, but it just seems "dry" somehow. I also have a military surplus GE 5670W tube from the 80's that kind of seems to split the difference.

If you're looking to play with tube audio on the (relative) cheap, the Schiit Vali 2+ is probably the way to go. Takes any 6DJ8 type tube, adapters for 5670/2C51, 12AU7, and 6SN7 tube types are cheap and plentiful, and the amp is less expensive than many of the tubes you can stuff into it.