Right of the bat I would return it due to the reverb not working. It could be a sign that the electronics have been damaged. As far as the buzzing it could be the tubes. turn on the amp and get a pencil with a rubber tip. Tap the tubes one by one and if there is a bad tube that has gone harmonic it will buzz, and you will be able to hear it. It sounds like a broken lightbulb filament in a bulb. That means you probably need some expensive tubes as well. Be careful not to touch anything else. Could be hair raising!
All in all you could be out a couple of hundred for repairs to the amp.
If you bought it that way and paid a very very low price you may have to bite the bullet. If not it should go back for repair. A decent speaker could also be a hundred plus.
A good set of tubes for that could be hundreds as well.
The Blues is alright!
Guitars: 1968 Gibson SG, 2005 Gibson SG Standard, 2006 Gibson LP Classic Gold top, 2004 Epiphone Elitist LP Custom, 1996 Gibson Les Paul Standard. 2001 Epiphone Sheraton II, 2007 Epiphone G400.
Fender Strats: 1996 Fender 68 Reissue CIJ, 2008 Squier CV 50s, 2009 Squier CV 50s Tele Butterescotch Blonde
Amps: Blues Junior Special edition Jensen in Brown Tolex with Wheat front, 65 Deluxe Reverb reissue,1970 Sonax reverb by Traynor, Avatar Custom 2/12 Cabinet with Eminence Legend V1216 speakers,
2008 DSL100 Marshall Amp , Fender Super Champ XD,Fender Vibro Champ XD
Effects and Pedals: Fulltone Fulldrive II, Fulltone OCD, Fulltone Mini Deja Vibe, Fulltone Fat Boost, Dunlop Crybaby Wah, Boss DS1, Boss DD20 Giga Delay, Boss TU2 tuner, Boss BD2, Ibanez TS9 Tube screamer, Zoom 505. Radial tonebone hot british.