I have, in my 15 minute audition at a local hifi shop, the WA5 (and by parity of reasoning, the WA5-LE) is in a different league from the Studio Six with the right tube combination. I felt it sounded closed-in and lacked exquisite details in the nuances which the WA5 delivers in spades. The WA5 sounded warmer and was more 'delicate'. The Studio Six was more solid statey. Might be a bit of an unfair comparison because the Studio Six may also sound better with upgraded tubes.
all woo amps are like this I think.
the WA6-SE is veiled and congested with grain with stock tubes, the WA2 is too muddy with stock tubes, the WA22 is colored and has a weird treble bite to it with stock tubes, a somewhat shouty midrange similar to WA6-SE, and the WA5 stock sounded pretty bad too, the detail and presence was there, but the sound was still unrefined, especially the treble.
woos are meant to be tube rolled and upgraded. I really wish jack would put decent/semi-premium tubes at least when he displays his amps at the meets. As you said, I think many of these bad impressions people have are partly due to this.
If you buy Woo amps you better be aware of this. The WA5 stock tubes I had were bottom of the line Shuguang 300Bs and 5U4Gs with a horribly microphonic GE 6SN7. Some say (jokingly) that Woo includes these tubes just to let you know the amp works. I understand why Woo does this though - a company cannot give any warranty on NOS tubes and unfortunately for the tubes Woo selects for most of its amps, NOS vintage tubes sound much better than modern production ones. It has to balance reliability with reasonably decent sound. But I agree with DG that Woo should put in some top end NOS tubes in its amps during meets.
Edited by lojay - 5/31/14 at 6:28pm