Tru-Fi Colordriver 18V

The Tru-Fi Colordriver 18V is an overdrive/fuzz pedal made in the USA and inspired by the Colorsound Power Boost, the 18V boost circuit from 1969¹². It is a recreation of that design: Delicious Audio's Paolo De Gregorio calls it "a true Power Boost replica done to the correct BC184 Transistors"¹. It runs on a normal 9V supply, with the voltage increased inside the pedal to 18V, so no dedicated 18V supply is needed¹.

From the Power Boost to the Overdriver

The Colordriver's family tree starts with the Colorsound Power Boost of 1969 and the Colorsound Overdriver of 1971, which Guitar.com's Richard Purvis describes as "essentially 18V and 9V versions of the same circuit"². The 18V Power Boost uses the same topography as the Overdriver but runs at 18V, as builder Zach of Tagboardeffects puts it⁴. In 1971, Colorsound changed the Power Boost to the 9V Overdriver, ending that 18V design until Tru-Fi's recreation⁵. Aion FX notes the Overdriver was itself an updated version of the circuit, a third revision from 1972⁶.

The Overdriver saw variations and reissues over the years, some with slight modifications to the circuit or enclosure design, according to Tru-Fi's own history article³. One example: in 1996 a reissue Overdriver was created that incorporated a volume pot on the output, though it included a resistor preventing it from going to zero volume⁵.

The 18V version versus the orange Colordriver

Tru-Fi makes the Colordriver in more than one version, and the difference comes down to voltage and parts¹:

• The 18V version gives a tad more headroom and transparency than the orange Colordriver¹
• The 18V uses different transistors, so the tone is a bit different¹
• The 18V is available in a series of different colors¹

Tru-Fi also builds other Colordriver variants, including the Tru-Fi Colordriver 9V version, the Tru-Fi Mini '69 ColorDriver, the Tru-Fi ColorDriver '71 Mini and the Tru-Fi Mini '71 Colordriver.

Controls and design

The pedal keeps its control layout simple. The main control is the gain, and a master volume sits on the side of the pedal so you can dial down the level for whatever use you desire, as De Gregorio explains¹. The enclosure is half the size of the original, a touch bigger than a Boss pedal, and while unique it still hints at the original unit¹.

As for what it sounds like, Delicious Audio describes it this way:

That is De Gregorio's description, not a measured verdict, but it places the pedal in the territory players associate with Jeff Beck-era boost-driven overdrive, in the same broad family as other overdrive pedals and fuzz pedals¹.

Power and practical notes

Power is the one specification worth reading carefully, because the pedal's name can mislead¹:

The pedal is true bypass and includes an LED and a manual¹. For players interested in the underlying circuit, Aion FX sells the Overdriver design as a DIY project called the Plasma⁶⁴, and the earlier version of the circuit as the Nucleus⁶⁴; the Tagboardeffects layout for the 18V Power Boost notes the original came with BC184L transistors but that any NPN silicon transistor should work⁴.

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