How good is the phono stage of the VAC sig.II pre-

It depends. I've got a Ren Mk2 (not Sig) which I used with the a ZYX Airy2 0.24 mv. The built-in phono w/step ups IS very good but it does not have adjustable loading. If your LO cart is sensitive to loading, you might not be getting the best out of it. I found the ZYX headamp into the MM phono was a little better; very very good, IMO. Held its own with a Doshi full function pre. Then I traded it in for the ZYX Artisan full phono stage, which I found to be remarkable. Just lets the music flow, good definition and thunderous bass. Neither has adjustable loading either, so I would recommend trying it with the specific cart you are going to use if you do not have a ZYX. As far as cost goes, an Artisan is about that same # you are talking about, maybe a little less but you will need cables.

I wouldn't own a phono stage or preamplifier without adjustable loading.

One size never fits all.

Sounding good and sounding optimally are entirely different.

Bill- generally good advice from Bill. However, neither the VAC internal, nor the ZYX Artisan are adjustable so that makes them equivalent in some way (although the VAC can be modified/pre-set at the factory). In my case, the VAC was pretty darn good and I assumed that the ZYX would be optimized for their cart. From what I heard, I was correct with respect to the ZYX for sure.