From the link:
"The front end of the amp is boosted with a Joyo Vintage Overdrive(TS-808 copy) with the Gain at 10 o'clock, Volume dimed, and tone in the middle. Brought into Logic using Ignite Amps' TPA-1 EL34 modeler and a mix of a T75 --> MD421 for the body and V30 --> SM57 on the cap for some attack."
I have since swapped the stock JJ preamp tube for a tung sol and the swap blew me away. Gave the amp much more gain than I thought it would have which lets me run the Joyo without adding gain, just using it as a clean boost. Also beefed up the low end a tiny bit and let me get rid of some fizz on top. I'm hoping to get some recording done soon so I can see what it does within a full mix, but I'm very happy with it.
Edit: He's Dead, Jim - I left the speaker cab connected just in case, though I've read a bunch of posts talking about it being solid state so it may/may not be an issue. Not sure about the headphone out and what load it's giving out.