Electro-Harmonix 6550 in ARC

I'm using the EH6550 now in my VT100 mkii. They replaced a set of winged C 6550s. Sound great to me...

I have tried both, but in a CJ amp. I like the Winged C better than the EH, just had more detail. Currently using the TungSol 6550, very good, balanced sound and tubes seem to last a lot longer than either the EH or Winged C's.