A recent purchase of a Fender Pro Jr soon led me down the upgrade path
. A 2 x 12" combo cabinet I built from an old 70's Fender closed back cabinet which started life as a Bassman 2 x 12 but was cut down to about 25" x 25" with a 15" still with original tolex and speaker cloth nicely aged. I fashioned a new speaker board for 2 - 12's I got from and old Traynor PA cabinet that was free. I know there's a lot bandied about speakers specifically for "guitar" but these sound great to me and my musician buddies and the amp has more than enough bass now compared to the 10" in the original Pro Jr cab. It's now open back style and the Pro Jr's 15 watts hot tube power drives the speakers for great volume much better than the original single 10". I also eliminated 90% of the hum in my amp by Isolating the heater wires and twisting them together as tightly as not to break it possible. Hum gone. In a conversion such as this. The chassis must bolt/screw on at 4 corners to eliminate rattling tubes. I had a broken off chassis screw and the resulting vibration to chassis showed up with a glassy ring at certain notes. Ring gone with the repair re-attachment of 4th screw. I believe that a single 12 would sound great as well as the Tonedog senior (pro Jr conversion cabinet) people can attest to but only in a larger cabinet than the Jr cabinet. Even if you stuff a 12 in there the improvement would be partial at best. Anyone else done similar conversions?
