ARC VT 100: MkII vs. MkIII?

The Mk3 adds a switch for bal/single ended, 12V power on/off trigger. Internally, it now has JFET for input, followed by a 6H30 driver/gain, and a 6H30 follower driving the 6550Cs. There are now four internal bias instead of two. The upgrade will set us back 1895 from Mk2 and 2695 from Mk1. I do not know how different the sound would be from the Mk2. BAT has been using this tube in their preamps for over a year now. Why ARCs moving away from 6922 for their new design? Could REF 3 preamp replace REF 2 next year to correct the tubey sound of REF 2? Oh! well.....

ARC has experienced high failure rates on the Russian 6922. In addition ARC is having problems with the factory. I own both the ARC LS25 and the VT100 mkII. I am not in a hurry to upgrade to the LS25 mkII or the VT 100 mkII. Leonard at ARC claims that the LS25 mkII wallops the LS25 mkI in every respect and is in fact clearly better than the Reference I. I guess we will see.......

I wasn't aware of the mkIII version. I have a LS15 and VT100 mkII and I'm completely satisfied and have over 500 hours on the original set of tubes. I think ARC upgrades are evolutionary not revolutionary, so spend your money wisely fellas. Isn't great to be an audiophile!!

I've experienced the 6922 tube failure that Gmorris mentioned (at locations V-7 and V-8). However, I do love the sound of this amp. That's why I'm curious about the sound of the upgrade. ARC has the technical info on the upgrade available as a fax (they're delaying, they say, posting to their website to coincide with other product introductions). The changes are as Ttl2000 says, which basically is the driver stage from the ARC VTM200-200W monoblock. BTW, I've also heard from an ARC dealer that 6922 failure was one thing that prompted the revision. However, what does this new version sound like? The guy I talked with at ARC said that the bass on the MkIII made the Mk II's bass response sound "wooly" by comparison. He also said that the new amp just sounds like a more powerful amp overall . But, what do less partisan ears think? America wants to know!

I talked to my dealer yesterday...he advised that ARC will be upgrading the entire line to the new tubes and set-up. He also said there is a clear difference in sound and said pre-amp upgrades will make a bigger difference than amplifier.The new tubes are of higher quality and will last substanially longer. The high upgrade cost should cause us all to analyze this fully before investing. Thank you ARC for upgradability and fantastic products.