Sovtek 5881 tubes in my 50+?

[mule#1]

I bought my 50+ used and it has (2) sovtek 5881 power tubes in it. I've used it that way for a long time but have alway's run 6L6's in the boogies in the past. Can antone explain the differences tonally?

 

[fishyfishfish]

To me, the 5881's sound a little darker in Boogies than the 6l6GC, nothing that can't be fixed with a quick turn of the EQ, but the difference is there.

 

[joey_truelove]

To me, the 5881's sound a little darker in Boogies than the 6l6GC, nothing that can't be fixed with a quick turn of the EQ, but the difference is there.

Not having tried the Sovtek so called 5881s but I understand that in this case Fishyfishfish's statement holds true. A valve more true to the 5881/ GB design (even one speced at GC standards) should have a softer and warmer response than your average 6L6GC and a different breakup pattern.