So i'm considering buying the Avalon Ultra Five Direct Box Instrument Preamplifier unit for my 1974 4001 Ricky bass. (my fender p-bass as a secondary bass) I'm saving for a nicer tube amp, and figured i could use one of these in the mean time, and use it later with my tube amp. Hopefully this isn't too stupid of a question, but are these things tube? analog? digital? I couldn't find much info on it, but does anyone have any personal experiences with these things that they would care to share? Thanks.