Anybody mod the Studio Projects VTB-1? I was wondering if there was anything i could about swapping out, like op amps/tubes/transformers, to get even more out of this preamp. Maybe use Burr Browns and Jensens. Possibley swap the Tube for a Mullard or something. If so do you know the part/model numbers? How benificial has your mod been? Thanks! ps. Anybody heard the SP828 yet?