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Crazy Tube Circuits Unobtanium Overdrive Pedal

In the world of guitar lore, two of the biggest Unicorns are the Klon Centuar Overdrive pedal and Dumble ampifiers. These mythical pieces of gear are hard to afford and even harder to find. Fortunately Crazy Tube Circuits has brought us the Unobtanium, a thoughtful mash up of these rarest of rare devices. Clearly there is no shortage of clones on the market, and how you take to the Unobtanium is more about how it sounds than does it nail the originals. Let's face it, very few of us have heard the real deals in person. That said, we like the Unobtanium

Klon Side - The Klone was heralded as one of the first "transparent" overdrives and the Unobtanium version is an open sounding pedal that can run from slightly hairy to pretty heavy crunch that thickens nicely as you twist the dial. To our ears the Unobtanium sounds a little sweeter and less angry than some other Klon Clones, which we kind of like. Moving the toggle from stock to mod ups the gain in an uncompressed manner which is nice for not getting lost in the mix. The Buffer/True bypass option is another neat feature, and how it affects your tone will depend very much on your pedalboard, cable runs, etc. We found the buffer setting added a good dose of high frequency presence, but not in a way we were crazy about. We liked the true bypass, but your results may vary.

Dumble Side - There is a better chance of getting hit by lightening than playing a Dumble, and the Unobtanium gives you twin Dumble Unicorns. We liked the clarity and note definition of the SSS, which gave us abroad range of musical grit and grind that was clear and articulate. The ODS has a deeper, huskier voice that really sings, and for years was the signature sound of guitar great Robben Ford. Neither setting gets really compressed unless you bury the gain knob, which is possibly the true magic of Dumble: Simultaneous grind, sustain and clarity.

You can stack both pedals, although you can't switch the order of them. And the very smart SND and RTN jacks allow you to place pedals in between them, so you are not stuck with Siamese Twin Unicorns. Lastly, the optional XT footswitch (about the size of a large marshmallow) provides remote access to the Stock/Mod and SSS/ODS toggles, giving you a four-voice stompbox that is all footswitch accessible. And any passive latching switch will work.

Accuracy to the originals notwithstanding, this is a great sounding pedal that provides multiple options for a broad range of overdrive and distortion that is tastefully musical and rich. Punk rockers and fuzz fans may not bond with it, but for blues, jazz, roots and classic rock it's killer. Add maybe a clean boost after it and your entire drive section could reside solely in the Unobtanium. We now believe in Unicorns.

In the words of Crazy Tube Circuits....

We've put your dream tones in a box!

The Unobtanium was inspired by 3 of the most mythical and sought-after pieces of music gear and combines their ultra-rare sonic elements. A magical tone overdrive meets two legendary amps. We have accurately recreated the circuit of the high headroom OVERDRIVE with the mystical blend of clean and overdriven tones and added extra features for versatility. AMP side uses an all-analog circuit to capture the tone and feel of two legendary tube amplifiers. From fat clean to sweet singing overdrive with blooming harmonic overtones. A passive effects loop gives you the option to connect your beloved pedals between your overdrive and amps in a box, building your ideal rig.


  • Right Side (Klon)

  • Gain: Controls the amount of drive. From transparent clean to high headroom thick overdrive as you turn clockwise.

  • treble: Controls the amount of high end frequencies, brighter as you turn clockwise.

  • volume: Controls the output volume. Features enormous amounts of output volume making it ideal to also be used as a preamp/booster.

    Voicing Toggle Switch:

  • stock: The original mythical drive circuit produced by the fabled germanium diodes.

  • mod: Higher gain/higher output, open sounding overdrive with less compression.

  • True/Buffer switch: Select between the original BUFFER bypass, adding clarity to your signal chain and running long cables without affecting tone, or TRUE bypass via a high quality relay.

    Left Side (Dumble)

  • Gain: Controls the amount of compression/drive. From clean boost to sweet singing overdrive.

  • emphasis: Adds gain and adjusts presence and bottom end response before the signal is overdriven. Brighter, tighter and enhanced pick attack as you turn clockwise.

  • tone: Controls the amount of post-overdrive high end frequencies, brighter as you turn clockwise.

  • volume: Controls the output volume. Features enormous amounts of output volume making it ideal to also be used as a preamp/booster.

  • Voicing toggle switch: Select between different amp voicings. 

  • ODS: Sweet singing overdrive with enhanced mid frequencies and blooming harmonic overtones. 

  • SSS: "Clean" drive with natural organic compression.

    Internal trimmers:

  • ODS BOOST trim: Adjust extra volume boost when voicing switch is set in ODS. From Oto 6 dB boost.

  • SSS LOW trim: Adjust low end response of SSS voicing.

  • Connections:

  • In/Out: mono instrument input/output.


  • Passive series effects loop. Connect your beloved pedals between OVERDRIVE and AMP or use the two sections as separate and independent effects. SEND is the output of the OVERDRIVE section, RTN is the input of the AMP section. SEND is connected to RTN when no jacks are inserted in the effects loop.

  • XT (optional) : Connect to an external footswitch to control AMP voicing. Use standard TS instrument cable with Crazy Tube Circuits XT footswitch or a passive latching switch (non-powered). Do not use an active switching circuit as it won't operate properly and can cause malfunction to the pedal.


  • AMP section does not feature a speaker simulation circuit. It is intended for use with another amp/speaker cabinet. We recommend using a separate speaker simulation device when going direct.

  • External footswitch bypasses onboard voicing toggle switch operation. Left side's LED turns half red when in ODS voicing. A barely noticeable momentary pop is perfectly normal when AMP voicing switch changes state.

  • Power supply: 9V DC center negative, regulated/ stabilized. Isolated power supply is recommended for best performance. Max current consumption 83mA