The Keeley Time Machine Boost is a two-channel, five-mode analog pre-amplifier and booster from Keeley Electronics, built for driving an amplifier into overdrive or saturation. It first appeared under the Legendary Tones name, a collaboration between David Szabados and Robert Keeley, and Vintage Guitar magazine reviewed it in March 2003 as a "Tri-Mode Signal Booster." After years of interest in the original version on the used market, Keeley reissued the pedal in June 2023, back in the original, smaller case12.
Vintage and Modern channels and the five modes
The pedal's two channels are labeled Vintage and Modern, and between them it offers five modes3. The basic idea, as the AMZ Guitar Effects review put it, is to flip between two boost tones, Modern and Vintage, with two vintage tones selectable via a mini switch4.
The two channels are built differently, and that is the heart of the pedal352:
- Vintage channel: inspired by rare germanium boosts like the Dallas Rangemaster, a treble booster3. It has two modes, "1966" and "1973," chosen with a toggle switch, plus an intensity control that adjusts high frequencies and harmonic content2.
- Modern channel: silicon JFET based, which Robert Keeley describes as offering "great transparency in contrast" to the germanium side5.
Each channel has its own volume control, so you can set the two boost levels independently2. The AMZ review noted that the vintage side's intensity control adjusts the treble boost, but that both vintage tones are "definitly tone/char" acter changers rather than clean boosts, in the reviewer's words4. In other words, the Vintage channel changes what your guitar sounds like, not just how loud it is.
Robert Keeley has used the pedal as an illustration of the broader difference between germanium and silicon designs, writing that "Classic germanium boost pedals inspired the Vintage channel"5.
What it does for your sound
RockBoard's PedalPedia describes the pedal as "a 2 channel, 5 mode pre-amplifier (booster) for driving your amplifiers into overdrive or saturation"3. That places it among boost pedals that are meant to be run into an amp that is already working, pushing the front end harder rather than simply making the guitar louder. The Vintage side goes further and reshapes the tone in the way treble boosters do; the Modern side is the more transparent of the two35.
The reissue in the original smaller case
In June 2023, Keeley announced that "Vintage" Time Machine Boost pedals were available again, with the redesigned pedal sold through the company's website1. The reissue matters for one practical reason: Keeley brought it back "in the original case giving it a smaller footprint"1. The original, smaller version of the pedal had been drawing a lot of interest on the used market, which prompted the reissue1.
The smaller case was not a drop-in change. Keeley notes that "This change required a new wiring scheme, so we put one of our finest builders on the job"1. The reissue and the original smaller version are therefore two distinct builds, even though they share the case size.
Power and setup
The pedal runs on 9V DC, center negative, and draws 200mA according to RockBoard's PedalPedia's current product listing3. The original review unit came with a 9-volt adapter included, and Vintage Guitar's 2003 review described it as running from a common 9-volt power supply42.
At 200mA, the Time Machine Boost draws more current than many boost pedals. Check that your isolated power supply outputs can supply that much before slotting it into a board, and be cautious about daisy chaining it with other pedals.
An English manual for the pedal is available from Keeley3.
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Questions
Is the Keeley Time Machine Boost analog?
Yes. Keeley lists the Time Machine Boost as an analog circuit, a two-channel, five-mode pre-amplifier or booster. It runs on a 9V DC center-negative supply and draws 200mA, so plan your pedalboard power accordingly, since that draw is high enough that a daisy chain with other pedals may not be practical.
How much current does the Time Machine Boost draw?
Keeley's product listing gives a current draw of 200mA at 9V DC with a center-negative plug. That is well above what many simple boost pedals need, so it is worth checking what your isolated power supply can deliver on each output before adding it to a board.
What is the difference between the Vintage and Modern channels?
The Vintage channel is inspired by classic germanium boost pedals, including the Dallas Rangemaster, and reshapes your tone as well as boosting it. The Modern channel is silicon JFET based, and Robert Keeley describes it as offering great transparency by contrast. Each channel has its own volume control.
Is the Time Machine Boost based on the Dallas Rangemaster?
The Vintage side is inspired by rare germanium boosts like the Dallas Rangemaster, which was a treble booster. The Vintage channel has two modes, 1966 and 1973, selected by a toggle switch, plus an intensity control for the treble boost. The Modern channel is not a Rangemaster-style circuit.
Is the Keeley Time Machine Boost still available?
Yes. In June 2023 Keeley announced that redesigned Time Machine Boost pedals were available again through the company's website, reissued in the original case, which gives the pedal a smaller footprint than the later version.
Why is the reissue smaller than the earlier version?
The 2023 reissue returns to the original, smaller case, which gives the pedal a smaller footprint on a pedalboard. Keeley notes that this change required a new wiring scheme, and the company put one of its builders on the job to handle it.
Sources (5)
- "Vintage" Time Machine Boost Pedals Now Available !!, Keeley Electronics Guitar Effects Pedals, 2012-06-18
- Legendary Tones Time Machine Boost, Vintage Guitar magazine, 2006-02-01
- Time Machine Boost by Keeley Electronics, RockBoard (www.rockboard.de), 2026
- Reviews of boost pedals, muzique.com (AMZ Guitar Effects)
- Germanium vs. Silicon Transistors, Keeley Electronics Guitar Effects Pedals, 2013-09-11
