I have been using GB Shuttle MAX 6.0 for over a year and really like this head a lot. The direct out is great. The only thing I changed was the preamp tube. I put my favorite tube in which is Mesa 12AX7 or whatever they call it. That tube is meatier and tubier than the stock tube which was OK, but I needed a bit more warmth in that channel. The FET channel sounds great too.
