The Hagerman Reactivator is an analog tube overdrive pedal, described by Delicious Audio as "a two-transistor / two-triode overdrive that runs the gamut from tonal warmth to growling distortion." It is built around a 12AU7 tube, which is included with the pedal, and it carries a separate Boost footswitch that "pushes extra gain into your amp when neded" alongside the main overdrive switching1.
How the circuit works
The Reactivator's signal path has three stages. A clean gain boost feeds a starved tube section, and the signal then passes through a tonestack with an output buffer. Delicious Audio quotes the builder's own description: "This pedal employs the starved tube section from my VALVE pedal, preceded by a clean gain boost, and followed by a tonestack with output buffer"1. In other words, the tube runs at a reduced operating point to shape the drive character, while the transistors handle the clean gain stage ahead of it.
The pedal is a development of the company's Valve mini-boost, so its lineage runs through Hagerman's earlier tube designs1. Players comparing it with Hagerman's other tube-driven drive pedal can read about the Hagerman Overdrive, or see how the broader category fits together on the Overdrive Pedals page.
Why it is called the Reactivator
The name is a nod to television repair history. During the early days of TV, if a picture tube grew dim, servicemen could perform a trick called "reactivation", where the heater voltage was overdriven to restore brightness. The pedal borrows both the idea and the name, reviving a tube by pushing it1.
Controls and power
| Control | Function |
|---|---|
| Drive | Sets the amount of overdrive |
| Bass | Low EQ |
| Treble | High EQ |
| Level | Output level |
The Reactivator runs on 9V at 135mA, and it accepts up to 12V1. Its 135mA current draw is high enough that a dedicated supply output is worth planning for on a shared pedalboard power supply. Input impedance is 110k ohm1.
The Reactivator is true bypass, so it stays out of your signal path when disengaged1.
Videos
gilmourish
EytschPi42
Brett Kingman
Questions
Does the Hagerman Reactivator come with a tube?
Yes. The Reactivator uses a 12AU7 tube, and it is included with the pedal. The tube sits at the center of the circuit, which is described as a two-transistor, two-triode design: a starved tube section fed by a clean gain boost and followed by a tonestack with an output buffer.
Is the Hagerman Reactivator true bypass?
Yes. The Reactivator is a true bypass pedal, so when it is switched off your guitar's signal passes through without going through the circuit.
What voltage does the Hagerman Reactivator run on?
The Reactivator runs on 9V power at 135mA, and it can accept up to 12V. Because of the relatively high current draw, a dedicated power supply is the sensible choice rather than sharing a daisy chain with several other pedals.
What does the separate Boost footswitch do?
The Reactivator has a second footswitch dedicated to boost. According to the writeup on Delicious Audio, this separate Boost footswitch pushes extra gain into your amp when needed, on top of the overdrive circuit itself.
Why is it called the Reactivator?
The name comes from an old television service trick. In the early days of TV, if a picture tube grew dim, servicemen could perform a trick called reactivation, overdriving the heater voltage to restore brightness. The pedal borrows the idea of reviving a tired tube.
What tube does the Hagerman Reactivator use?
The Reactivator uses a 12AU7 tube, which is included with the pedal. The circuit is described as a two-transistor, two-triode overdrive, with the tube's starved section fed by a clean gain boost and followed by a tonestack with an output buffer.
Sources (1)
- Hagerman Reactivator Tube Overdrive, Delicious Audio, 2022-05-16
