Anybody use a 5687 tube inplace of a 6sn7?

@audioman58 four posts? 10,000 hours? Are you sure you’re not thinking of 5692, because that certainly doesn’t sound like a 5687.

5687 is a 9 pin I stand to be corrected I was referring to a 5692.
and 10,000 hours for Any tube is not common or likely .

a 6sn7 has a different Sonic characteristic ,for sure worth checking out 

especially matched NOS tubes.

5687 is a 9 pin I stand to be corrected I was referring to a 5692.
and 10,000 hours for Any tube is not common or likely .

a 6sn7 has a different Sonic characteristic ,for sure worth checking out

especially matched NOS tubes.

It’s crazy how tube numbers can be so close when the tubes themselves are vastly different! I did try some of the red base 5692 in place of 6SN7 in the aforementioned Singlepower headphone amp. They were nice, but just not for me.

The 5692's 10,000 hours rating assumes you’re keeping within guidelines for rated voltages, dissipation etc. IIRC 5692 specs a max plate voltage of only 250V. 6SN7’s are 350V, with GTA and GTB versions going up to 450V. The 5692’s plate dissipation was also lower. When you drop a 5692 into some 6SN7 circuits you’ll be exceeding its ratings! Sometimes by a lot. The vaunted 10,000 hour rating goes out the window at that point.

5687 are mini 9-pin dual triodes that look similar to a 12A*7 series tubes except with different plate structures and very different operation. I can’t understate how damn HOT these 5687 tubes get. You don’t expect it from such a small tube - easy to burn the crap out of yourself by accident if you’re rolling.