What a Digital Modelling Amp
should be
In the Valve Reactor power amplifier, a 12AX7 dual-triode valve (12AX7s are typically used as preamp valves) is connected directly to an output transformer. Our amp designers had to develop a way to raise the output level to one which could actually drive speakers to stage volume levels while maintaining the integrity of the valve-amp sound and feel. We accomplished this by creating a circuit of proprietary design dubbed the VOX VariAmp Power Circuit. The output transformer is connected to this new VariAmp Power Circuit which uses Constant Current design and Reactive Feedback technology.
The VariAmp Power Circuit cannot be overdriven, is totally transparent and can be configured to be 1, 15, 30 or 60 Watts. The VariAmp Power Circuit does not color or change the signal in any way and the resulting output tone is pure. It also ensures that the output signal maintains the high dynamic range associated with traditional valve amps- something most solid-state amplifiers simply cannot deliver, and one of the primary reasons why valve guitar amps normally sound and feel so much louder and more alive than solid-state amps boasting the same output power rating.
The Reactive Feedback technology used in the VariAmp Circuit "reads" the impedance curve of the speaker and then reports this reactive information back to the secondary side of the output transformer. This information is fed back to the primary side of the output transformer and therefore changes the loading on the valves, another important part of the vital role an all-valve power amp plays in the creation of traditional valve tone.