Rock guitar tone has long been defined by overdriven tube amplifiers. Those tones have evolved over the years as amps were intentionally designed for more gain and a more focused overdriven sound.
You want those tones all the time, but we all live in the real world. You head out to a gig not knowing how loud you can play, whether you're amp will be mic'd or how much of an amp you can even fit on the stage. Your practice space is tiny and even the drummer thinks you are too loud. And of course you need to practice without waking the neighbors on occasion. We get it. We've been there too.
The Variac Overdrive emulates both a hot-rodded tube preamp and a power amp with two phase inverter options. Chords sound huge, leads sing with clarity, and pinch harmonics come out with ease. The Variac Overdrive is an expressive overdrive pedal with the articulation and touch sensitivity of a tube amplifier. The controls are interactive along with "hidden" controls like the power supply. Dynamics and headroom are all affected by the power supply. Powering from 7.5 to 18 VDC opens up even more possibilities. More on the "hidden" controls below.
With tones ranging from AC/DC, early Van Halen, Judas Priest to Tom Morello and even 80's hair sounds, the Variac Overdrive is more than another amp in a box. It places an entire era of rock tone at your feet. It's based on tests of individual tube circuits, careful listening to some of our favorite rock and old school metal, and the topology of amplifiers the artists actually used.
The "hidden" controls:
These are not internal switches or knobs. No these are hidden plain sight.
Playing loud makes a big difference. A big part of guitar tone is simply turning up to the point where the interaction between volume in the room makes notes sustain, harmonics bloom and simply sounding on the edge of being out of control. The Variac Overdrive is designed to react like an amp when it's loud. It's a great pedal for practicing without waking the neighbors, but do yourself a favor and turn it up whenever you can.
The power supply is an important part of a tube amplifier. It has a significant impact on The Variac Overdrive as well. It can be powered from 7.5 to 18VDC with wide changes in dynamics and compression. The sweet spot is usually about 8-15 volts, but will depend on your gear and playing style.
Your guitar becomes and important part of the circuit too. The volume and tone controls offer a huge pallet of sounds on their own, and the Variac Overdrive let's the individual personality of each guitar shine through.
The control matrix:
Preamp - controls the preamp gain
Pentodes- controls the power amp gain
Tone Stack- The treble and bass knobs control the frequency response.
Cathodyne / LTP switch- Two common tube amp phase inverters. Cathodyne setting has more bass and a looser response. LTP (long tail pair) for tightening up the low end and a more focused sound. This switch has more influence with more pentodes gain. In general for smaller amps you'll want to set this switch to cathodyne, and LTP for amps with two or more speakers.
Volume- makes the effect louder or quieter if you are in to that kind of thing.
For a deeper explanation check out www.subdecay.com
Get loud and get ready to rock with the Variac Overdrive.