Radial Switchbone

The Radial Switchbone is an ABY amp switcher and booster: a pedal that lets one guitar feed two amplifiers, switching between them or running both at once, with a built-in clean boost on top. Radial describes it as "a high performance ABY designed to deliver the natural tone of your instrument to your amps without introducing noise or artefact"¹. Radial's own support pages put it plainly: products like the Switchbone and the Twin-City "are designed to run two amps and will do a better job" than simpler approaches².

The Switchbone line began as the Tonebone Switchbone, an ABY amp switcher that became a favorite of players including Derek Trucks³, and was later updated as the Switchbone V2, an amp switcher and booster¹. Radial's product page now states that the Switchbone V2 "has been discontinued and is no longer shipping"¹, so secondhand units are what a player will find today.

What the Switchbone does: two amps from one guitar

At its core the Switchbone is a standard ABY setup: guitar in, two amp outputs, and a footswitch that selects amp A, amp B, or both. Vintage Guitar's 2004 review of the original Tonebone Switchbone described the control set: "The Switchbone features a stomp switch for running both amps simultaneously, a toggle switch (with indicators) that allows one or the other amp to be on and choosing which amp defaults when 'Both' is turned off, [and a] 'Boost' switch engaging a boost circuit with indicator light"⁶.

The boost gives up to +12dB of baseline gain above unity⁵, and the buffer section can be set to zero-gain or a user-adjustable level⁴. A drag control varies the input impedance⁵, which lets a player load the pickups the way a particular amp or cable length would, shaping the feel of the guitar into the box.

The original Tonebone Switchbone also carried two input jacks: one buffered, for guitar signals with no preamp, and one direct, for signals that had already been preamped⁷. All three original versions shared the same rear panel: two amplifier input and output jacks, one speaker-out jack, and a Slingshot remote switch jack⁷.

Power and connections: 15VDC, discrete Class-A

The Switchbone V2 runs on 15VDC from an included power supply, connected through a dedicated 15VDC jack⁴. That voltage means the Switchbone needs its own adapter rather than a shared pedalboard supply.

The audio path is 100% discrete Class-A¹, the same award-winning Class-A circuitry Radial uses in the X-Amp⁸. Radial's support documentation also notes that the Switchbone shares its Class-A circuit architecture with the Elevator buffer, arranged with a different feature set⁹. Radial's spec sheet lists the noise floor at -111dB and output impedance at 10k Ohm⁵.

Isolation and remote switching

The Switchbone has transformer isolation inside, which is what lets two amps run at once without the ground-loop hum a plain Y-cable can produce. Radial's support article on the BigShot EFX makes the contrast explicit: "there are no provisions for transformer isolation like inside the Switchbone™ or BigShot ABY™"¹⁰.

The Switchbone V2 also carries Radial's Slingshot remote switching. Radial describes it as a feature that "lets you send an on-off type command to other external devices via a ¼" cable and contact closure," triggered by either the Boost or the Toggle footswitch⁴. In practice that means the pedal can change an amp's channel or drive other switching gear without touching the amp.

Versions: VT, SS and TS

The original Tonebone Switchbone shipped in three versions, as Vintage Guitar's Bob Tekippe explained in 2005: "It's available in three versions specifically for tube heads (VT), solidstate heads (SS), and the TS lets you switch bet[ween]" tube and solid-state amps⁷. The VT, SS and TS shared the same jack layout and overall design, differing in what amp pairings they were built to handle.

What reviewers and players said

Vintage Guitar's 2005 review, which tested the Switchbone with Peavey amplifiers, concluded that the Switchbone "does exactly what it promises, and do[es] it very well"⁷. The review priced the original versions at $300 each retail in 2005⁷.

The pedal also found its way onto pro boards. In a 2014 press announcement, Radial's Peter Janis noted that "the Radial Switchbone has become a favorite ABY switcher for a number of toneaholics including Derek Trucks"³.

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