#1
Is there a way to just my Peavey Classic 30 combo amp as just a cab? Is it possible to run a head into the combo and use the combo as a cab? And if so, how would I do that?
Current/Main Gear
'06 MIA Fender Stratocaster
'97 Epiphone Les Paul Standard Lim. Ed.
'90s Peavey Classic 30
H&K Tubemeister 18
MXR 404 CAE Crybaby
Ibanez TS9
Ernie Ball Jr. Volume
Digitech Hardwire DL-8
TC Electronic Nova Repeater
#2
yes it is possible

Get a spade to male 1/4"
remove the connectors on the speaker
connect new spade connecter>1/4"
plug make en into new amp with correct ohms selected
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#3
depends on how the speaker in the back is connected, you'd have to unsolder the amp's connection to the speaker and create some kind of jack that will allow you to replug the amp back or plug in another amp into the speaker. 1/4 female mono on the speaker end and 1/4 male mono on the amp side should do it. The other amp should already allow for a speaker cable so you can connect directly into it. If you're not sure - talk to an electronics tech in your area, it shouldn't cost much to do as it is an extremely simple procedure.