Audio Research Ref 3 Opinions

I called ARC and asked if there was a upgrade for my Ref 3 and was told that there wasn't. I see on their site they still list the 6H30 tubes for the Ref 3. Will call back and talk to them again about this.
Has anyone else called?

Well, this gets curiouser and curiouser! The Toronto dealer for ARC told me she prefers the old 6H30 sound to the updated 6550C sound, which implies addmitting the existance of the update. Furthermore Oneobgin has just paid $59 + shipping to ARC to supply 4 6550C tubes and related bypass caps. He had the update performed by his California dealer. If anyone speakes to Leonard at ARC tomorrow please post here. Just make sure you do not call it an upgrade but a 'rolling update', which is the term used by ARC. There is no version change on Ref 3 at all.

Ok, I talked to ARC just now. All is clear to me and confirms what Oneobgin said all along.

1) Tube swapping> only the one 6L6GC is swapped in favour of a 6550C (Svetlana made).
Not the 6H30 on the output section but the rectifier on the power supply.

2) The addition of 4 bypass caps is also part of this "rolling update".

The tube swapping can be done by ourselves provided we get the right tube brand (Svetlana).

I don't know how much of an improvement this may result, but spending a few $ on a tube is not a lot to find out ourselves.

brgds, marcelo

btw, the right tube to use, according to ARC itself, is the Winged "C" (SED) 6550 C. Same as the ones they currently use.
brg,ds marcelo

Ok, Tube swapping: the one 6L6GC is swapped in favour of a 6550C (Svetlana made).

Where are the four bypass caps installed?

Can I go "back" from the 6550C to the 6L6GC? and leave the bypass caps installed?