George Callobre's 12-String Bass Rig

George Callobre from Chicago, Illinois


George's Complete Bass / Guitar Rig

"I am very fortunate to have put together a fantastic Bass rig with the following components:

Kern IP-777 - A point-to-point, hand-wired all-tube preamp that sounds like an SVT in a single rack space;
Peavey DPC 1400x - A 700 watt per channel stereo power amp with headroom to spare;
Epifani T-210 cabinet - An 8 ohm 2x10 cab with power handling of 400 watts RMS;
Epifani T-212 cabinet - A 4 ohm 2x12 cab with power handling of 600 watts RMS;
Bag End S15 D - An 8 ohm 1x15 cab with 200 watts RMS power handling;

Barber Electronics Tone Pump II - A boutique guitar distortion pedal with two stages of gain available. I'm fairly impressed with the sensitivity of this pedal. If you turn up the bass, you get more crunch, and you can set the gain and overdrive in a bunch of different ways."

"I usually use either the 1x15 and the 2x10 together or the 2x10 with the 2x12, but when I need (or want) more bottom, I can run the 1x15 and 2x10 on one channel and the 2x12 on the other channel. What a sound!!!"


"I also own an Eden Metro Combo, a 600 watt RMS tube / solid state hybrid amp that was my main amp until I bought the Kern / Peavey amp. This is a great stand-alone amp and it works very well when paired with the Bag-End 15, which I bought for that purpose."

"I usually set my basses up for fairly low action, set the input gain fairly high (like 2:00 on the dial) and play with a fairly light touch or pick stroke. This is a trick I figured out and then learned that it is the way the reggae players get that super deep sound. You can still dig in and then you get a bit of (or a lot) of overdrive, but it still sounds like a BASS. Good gear helps, but I've done this with small amps too, and it works."


Guitar Amp - Dr Z MAZ-38 “Senior NR”

"I added a Guitar Amp to my Bass rig after owning my Hamer Chaparral for a few months because I wanted to get the kind of overdrive that only real tubes can supply. These are the components of my Guitar Amp:

Dr Z MAZ-38 “Senior NR” - A 38 watt hand-wired tube amp with 4 EL-84’s for the power section and a GZ-34 tube rectifier. The MAZ-38 has a very smooth, thick tube distortion that allows all the notes to shine through clearly. The amp is also very touch-sensitive, so you can really control the amount of overdrive very easily by adjusting your pick attack or pickup choice.

Avatar G212H Cabinet - A 2x12 Guitar Cab loaded with 2 Eminence V12’s rated at 120 watts RMS each. I chose these speakers because they had more power handling than the typical guitar speaker and because they are designed to have the vintage English speaker 'cone breakup' that contributes to the 'crunch' of an overdriven guitar tone. So far, they have taken all the sound I have thrown at them and they are sounding amazing with the Dr Z amp."

"Chandler Royale 12’s output 1 plugs into the Kern Preamp input. Output 1 typically has the neck and center pickups routed to it. Output 2 plugs into the Dr Z amp’s low gain input. Output 2 typically has the bridge pickup routed to it. I am not using the Tone pump with the Chandler bass very much because I really like the natural interaction of the very hot Chandler pickups with the tubes in both the Kern and the Dr Z amps."

"Hamer Chaparral 12 plugs into the Kern preamp input. Kern Effect output plugs into Barber Tone Pump II. Tone Pump output plugs into Dr Z amp’s high gain input. The Tone Pump’s reduces a bit of the bass content the guitar amp receives from the Hamer, so that helps protect the guitar speakers from damage. The Tone Pump can also be set to compress the signal a bit (or a lot, if you prefer) which also smoothes out the sometimes 'brittle' sound the Hamer’s EMG pickups can produce."

George's Hamer B12M Semi-Hollow Body 12-String Bass