6SL7 Tube rolling - my experience

[beau2317]

For what it's worth I wanted to share my recent experiences with various 6SL7 tubes, as I have discovered a gem...

I was trying a bunch of different 6SL7 type tubes in the first position in an Aikido voltage amp (for my hybrid moskido amp...see other thread)

Among the tubes I tried were:

RCA red base JAN NOS 5691
Sylvania 1959 JAN NOS 6SL7W
Russian 1579 special military development 6SL7
Standard russian 6SL7
Tung Sol 6SL7

OK so it's not an exhaustive list, but the RCA red base should be pretty good. And it is. But the russian 1579 is better. The others are all considerably worse.

Now the 1579 is an interesting tube. There is a similar "special" russian 6SN7 version, the 1578. Both of these tubes are non-microphonic, unlike a lot of 6SL7/6SN7s

A year ago you could pick these up 1578s for $30 each. But they have been discovered now as excellent sounding 6SN7s, and there is only one guy selling these on ebay, just two per week. And the prices are usually over $100 for a pair, sometimes $140

But my point in this thread is to mention that the 6SL7 version, the 1579, is still relatively cheap. You can pick these up for only $8.50 a pair (I bought 6 for $22) so this is a real bargain.

Maybe in a year's time they will have been discovered and the stocks might be low. So pick some up now (on ebay) while you can. Search for "1579 tube"

Note that I have no commercial interest in this. Just sharing what I have found...