Thanks Myles.
I contacted them and they gave me the phone number of their former designer (the guy who designed the amp) and I'm still trying to get ahold of him. Unfortunately he doesn't seem to have email.
Thank you.
UPDATE: I just got ahold of Terry Laul (the designer) who couldn't help with an owner's manual but gave me the lowdown on the kinds of tubes used in the head and also told me to hang on to his number because he still has transformers, pots and other parts used in the amp available in case my guitarist ever need to replace anything. Very cool in my book.
All in all, very pleased with Dean Markley customer service and Terry Laul.