VTL 6550 vs. KT90?


I own a pair of VTL 750's and was looking to replace the 24 6550 tubes. Has anyone tried the KT88 or the KT90 as compared to the 6550?
hifimeomy
No,i haven't compared them in a VTL amp, but in Jadis 80 mono, Sonic Frontiers Power 2 and CJ.Same result! Kevin at www.upscaleaudio can tell you the best tubes with a VTL amp.He retubes all the amp and he is very honest and friendly.Contact him!Ciao.Marco from Italy....
This is a really old thread, but has anyone ran KT90s in a VTL ST 150, instead of 6550? I have KT 90 225 Deluxe monos and really loved them.  Curious what the bias difference if possible would be in the ST150.  Cheers.