Pigtronix Philosopher's Tone

The Pigtronix Philosopher's Tone is an analog compressor and sustainer pedal, a vactrol-based compressor and overdrive first released in 2009 and designed by Howard Davis¹. What set it apart from most compressor pedals of its era is its parallel design: the compressed signal sits alongside your untouched dry signal, and a Blend knob lets you mix the two, so you can add sustain without losing the snap and dynamics of your original tone²³.

Pigtronix built the pedal around optical compression, using a vactrol (a light element and a light-sensitive resistor in one package) as the gain-control element rather than the chip-based voltage-controlled amplifiers in many studio-style pedals¹. Premier Guitar's demo from the 2009 NY Amp Show described it simply as "an analog compressor and sustainer"², and the pedal went on to be described in Pigtronix press material as award-winning and top-selling⁴.

What it does: parallel optical compression with clean sustain

The core idea of the Philosopher's Tone is clean sustain. Pigtronix's own description, quoted in the press release for the Micro version, calls it famous for "noiseless clean sustain" and says it "stands out as a uniquely powerful guitar effect"⁷. Because the compressor works on a parallel path, the effect can push a note into long sustain while your dry signal keeps its attack, which is what the Blend knob controls.

MusicRadar's Trevor Curwen, reviewing the original, found it useful in two very different jobs: it "can tighten up dynamics for arpeggiated chords or country picking as well as delivering a shedload of clean sustain," and he noted the pedal also offers "smooth diode clipping distortion on tap"⁵. That distortion side is the overdrive half of the circuit, and it became the seed for several later versions of the pedal.

The controls

The original pedal carries five knobs and a bright LED indicator⁶. Across the Philosopher's Tone family, the control set stays consistent:

The Blend knob is the one that defines the pedal. Pigtronix's own artist page explains that it "allows you to mix your original tone with the compressed sound, making even the mos[t] extreme settings" usable³. MusicRadar's review of the Micro put the same idea in player's terms: the Blend knob "means you can add in gradual amounts of compression in parallel with your dry signal, right up to a fully compressed signal"¹⁰. Guitar World's mini-pedal buying guide listed the Micro's blend control for parallel compression and its treble EQ among the pedal's strengths, along with noiseless clean sustain, and observed that it doesn't get as "squashy" as some compressors¹¹.

The manual takes an unusual approach for a pedal: Delicious Audio's review noted that it "describe[s] the philosophy behind the pedals, provide[s] starting point settings which are quite useful"⁶.

History and versions

The Philosopher's Tone line grew into one of Pigtronix's most revised pedals, with the original 2009 vactrol-based compressor & overdrive followed by later editions such as the Philosopher's Tone Micro, released August 1, 2016¹⁷.

Philosopher's Rock and Philosopher's Bass

The Philosopher's Rock is a simpler version of the Philosopher's Tone that emphasized the overdrive component¹¹². Pedal of the Day called it "a simpler version of another Pigtronix classic, the Philosopher's Tone"¹³, and Premier Guitar's review noted that "Volume and sustain controls remain, however" from the original¹². Aion FX also records a Philosopher's Bass variant, "which was tuned for bass frequencies," both versions replacing the original in the lineup¹.

Philosopher's Tone Micro (2016)

Available as of August 1, 2016, the Philosopher's Tone Micro condensed the Philosopher's Tone, the vactrol-based compressor and overdrive Pigtronix first released in 2009, into a smaller enclosure⁷¹⁴¹⁵. Pigtronix described the original as its award-winning and top-selling compressor⁴. Aion FX traced the circuit and found a gain resistor, labeled R7 in the SMD 1590B version, marked "6802", which is 68k, on a unit dated around 2011 to 2012¹⁵.

Germanium Gold Micro (2018)

The Philosopher's Tone Germanium Gold Micro is another compact version of the Philosopher's Tone, the vactrol-based compressor and overdrive first released in 2009²¹. Like the original, it carries a Blend knob that lets a player mix their original tone with the compressed sound⁸³. MusicRadar's reviewer called the Philosopher's Tone "a versatile addition to any pedalboard"⁵, and Guitar.com's Richard Purvis also reviewed it⁵.

Philosopher's Tone 2 (2024)

The Philosopher's Tone 2 is a second-generation version of the Philosopher's Tone, the vactrol-based compressor and overdrive Pigtronix first released in 2009⁷¹¹⁶. Its Blend knob allows the player to mix the original, uncompressed tone with the compressed sound³¹⁷¹⁸. Reviewers have found the Philosopher's Tone a versatile pedal, with MusicRadar calling it "a versatile addition to any pedalboard"⁵. ===

What reviewers said

MusicRadar's review of the original praised its versatility, calling it "a versatile addition to any pedalboard" and noting that its horizontal layout helps with pedalboard positioning⁵. Guitar World's mini-pedal guide highlighted the Micro's noiseless clean sustain, parallel blend control and treble EQ¹¹. For the Germanium Gold Micro, Guitar.com's verdict was 9/10¹⁹, and MusicRadar's review credited the Blend knob for letting you set a mix of dry and compressed sound⁸.

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