I'd like to give a shout out to RogerB who sent me a pair of Russian 6ZHIP-EV driver tubes absolutely free of charge. He even went so far as to send them priority shipping, so I could have them last weekend.
I've been listening to them all this week, (around 30 hours thus far) and I think they are wonderful. To my ears, they have a much wider soundstage than the stock drivers. It seems the Russians get along much better with each other. These have the groove in them and they are mucho groovy!!! I've been listening to all kinds of music..rock, jazz, bluegrass, and they seem to easily handle each genre well. My stock tubes were great for rock and bluegrass, but I think the 6ZHIP-EV really shines with small combo jazz.
I've been very pleased with the my stock drivers, but these new tubes really take it to another level.
They just get better with more "burn In". Enjoy!!