VAC Preamp

Does anyone have experience with the VAC Standard or Standard LE preamp? I was thinking about a used one and having it retrofitted to accept a balanced input for my SACD unit. I am wondering whether the sound was "tubey" or not and whether the quality of the unit was worth the price. Also, any comparisons to Aesthetix or other preamps would be appreciated. Thanks in advance.
Can't help you with the Standard series but the Rennaissance seris is not tubey. Not cheap but well worth the price, IMO.
Put in Chinese tubes and it will not sound tubey, put in Mullards and all pre's will sound tubey.
The Renaissance preamp comes already fitted with balanced ins and outs. Build quality is worth the price.
I own VAC equipment (the Renaissance 140/140 300B monoblocks) and did hear the Standard preamp, finding it to be nothing special. The circumstances were my friend's attempt to find a very high end preamp -- he tried three or four preamps and bought a CAT Mk. III, which clearly sounded superior (which is to be expected given the CAT was twice the price of the VAC).

VAC's Renaissance preamps, along with the "Phi" preamp, are VAC's premium preamps and they are among the very finest tube preamps available, but are of course very expensive. Good deals can be had on them used.

As you specifically intend to use a balanced source component, I would consider the Audio Research LS-5 (+/- $3,000 used), the Rowland Coherence II (+/- $6,000 used) or Audio Research Reference 3 (hard to find used and about $9,000 if purchased new). All offer supurb sound for the money (in fact, Mr. Johnson could have retired after building the LS-5, as it is pretty hard to justify more preamp in my opinion).
The VAC Ren would fit right near the low end of that range and it will do balanced in and out. Used cost should be +/- $5K depending on whether you need phono or not. If you can swing it it is a great pre-amp, IMO. HT pass thru and a very good remote if you need/want those features.
I've had a VAC Standard LE and didn't find it "tubey" at all. In my system, I directly compared it to a $10K Thor pre and the VAC at 1/2 the price won me over. Excellent detail, imaging and most of all, musicality. High quality build and excellent support from VAC are the icing. The Renaissance sound like the best fit for you, as others above had mentioned. Good luck.
P.S. - I now have a Phi 2.0 pre and a Phi 300.1 amp on order.
I don't believe that the VAC standard preamp features a truly balanced (fully differential balanced) circuit, but rather, has a single-ended circuit with a few XLR connections. This would not at all be a bad thing -- balanced circuitry in audiophile equipment is of arguable utility.

The VAC Renaissance preamps evidently do feature a fully balanced circuit.