Yes, you can use an EQ pedal to shape your tone, the VJ actually takes to pedals quite well. It has only a volume control, no tone, no nothing else.
That can be changed if you like to mod amps, however. There are several "kits" on E-Bay that allow you to add tone controls, gain controls, etc., although they are a bit expensive IMHO. Most of them can be done for a few dollars if you research the amp's circuit on the net, and can use a soldering iron. Of course, it voids the warranty, and there are HIGH voltages in a tube amp that can KILL YOU if you don't know what you're doing, so I would not recommend it w/o the proper training or experience. But there are plenty of things that will improve it's sound.
You can replace the stock tubes (which I highly recommend), to make the amp smoother and more toneful, and from there the sky's the limit, depending on how much you want to spend, and whether or not you're into modding your own gear. Or you could find a good amp tech and have it done for you.
I've replaced the tubes on mine w/ JJ Teslas from Eurotubes, replaced the stock output transformer with a Hammond 125DSE, and changed a few resistors and lifted the leg of the C3 capacitor on the printed circuit board.
All of this has made the amp sound much better. I only did 1 mod at a time, in case I didn't like something, I could go back and undo w/o trying to chase down what did which to whatever that I didn't care for.
The stock VJ sounds pretty good, but if you're willing to spend another $50 or so after the $99 initial investment, you'd be surprised what it will do.
Guitars
Wilburn Versatare, '52 FrankenTele(Fender licensed parts), Fender USA Roadhouse Strat, Fender USA Standard B-bender Telecaster, Agile AL 3000 w/ WCR pickups, Ibanez MIJ V300 Acoustic, Squier Precision Bass,
Amps
Ceriatone Overtone Special, Musicman 212 Sixty-Five, Fender Blues Jr., Peavey Classic 30, Fender Super Reverb, Traynor YCV-40 WR Anniversary w/ matching 1x12 ext. cab, Epiphone SoCal 50w head w/ matching 4x12 cab (Lady Luck speakers), Avatar 2x12 semi-open back cab w/ Celestion speakers
Pedals
Digitech Bad Monkey, Digitech Jamman, DVM's ZYS, Goodrich volume pedal