The Subdecay Variac Overdrive is an overdrive pedal that emulates both a hot-rodded tube preamp and a power amp, with two phase inverter options. Subdecay describes it as an expressive overdrive with the articulation and touch sensitivity of a tube amplifier, aimed at vintage rock, hard rock and old school metal tones and more1. It sits in the overdrive family, alongside other Subdecay drive pedals such as the SubDecay Liquid Sunshine, the Subdecay SuperNova Drive and the Subdecay Gain Theory GT1.
How it works
The Variac's approach splits the amp model into stages. It has individual controls for preamp and power amp overdrive, which Subdecay says allows both vintage and modern sounds1. In a tube amplifier, the preamp and power amp each contribute their own kind of breakup, and having a control for each stage lets a player blend them rather than relying on a single gain knob.
The power amp side includes two different phase inverter styles1. The phase inverter is the stage that splits the signal to drive the power tubes, and different inverter designs are part of what gives different amplifiers their character, so the switch changes how the emulated power amp section responds.
Subdecay says the design is based on tests of individual tube circuits and careful listening to favorite rock and old school metal, following the topology of amplifiers the artists actually used1.
Power and size
The pedal accepts 7.5 to 18 VDC, and Subdecay notes that powering across that range opens up even more possibilities1. That is a wider window than many overdrives accept, so the supply voltage itself becomes part of the sound.
The maker's product page listed the Variac Overdrive as weighing 12 oz1.
For board planning, the enclosure measures 4.375 × 2.375 × 2.25 inches and weighs 12 oz1.
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Questions
What voltage does the Subdecay Variac Overdrive need?
Subdecay lists the Variac Overdrive as accepting 7.5 to 18 VDC. That range is wider than many pedals accept, and the maker notes that powering across it opens up more possibilities, since the supply voltage changes how the circuit responds. As with any pedal, use a center-negative DC supply of the correct polarity and check the maker's guidance before connecting anything other than a standard 9V supply.
What does the phase inverter switch do on the Variac Overdrive?
The Variac Overdrive offers two different phase inverter styles. In a tube amp, the phase inverter is the stage that splits the signal to drive the power tubes, and different inverter designs contribute different feel and character to an amp's overdrive. The pedal emulates both a hot-rodded tube preamp and a power amp, and the two inverter options are part of that power amp emulation.
What kind of tones can the Subdecay Variac Overdrive make?
Subdecay describes the Variac Overdrive as covering vintage rock, hard rock and old school metal tones and more. The pedal has individual controls for preamp and power amp overdrive, which the maker says allows both vintage and modern sounds, and it is built to have the articulation and touch sensitivity of a tube amplifier.
How big is the Subdecay Variac Overdrive?
Subdecay lists the Variac Overdrive at 4.375 by 2.375 by 2.25 inches, with a weight of 12 ounces. That is a compact footprint by pedalboard standards, small enough to sit alongside standard enclosure pedals on most boards.
Sources (1)
- Variac Overdrive, Subdecay, 2024-03-30
