“Whether you’re an AC/DC fan or not, there are some classic tones to be found within this little box of rock”: Crazy Tube Circuits Heatseeker review (2025)

What is it?

Crazy Tube Circuits has a penchant for creating pedals that pair classic amp sounds with a classic drive or boost pedal.

Following on from the Crossfire, Unobtanium and Hi-Power is the fourth in that twin-footswitch series, the Heatseeker, which is inspired by the gear setup of AC/DC’s Angus Young, pairing a Marshall amp sound with footswitchable boost, plus enhancement from the circuitry of a vintage wireless system.

The amp portion of the pedal offers a choice of three different Marshall models with full tonal control available via a six-knob array consisting of Volume, Master, Bass, Middle, Treble and Presence knobs.

Specs

• PRICE: $279/£235/€279
• ORIGIN: Greece
• TYPE: Drive pedal
• FEATURES: True bypass
• CONTROLS: Master, Volume, Presence, Bass, Treble, Middle, Level, Enhance, WoS switch, AmpVoicing switch (45/SL/MV), Amp Bypass footswitch, Boost Bypass footswitch
• CONNECTIONS: Standard input, standard output, standard send, standard return
• POWER: 9V DC adaptor (notsupplied) 115mA
• DIMENSIONS: 118 (w) x 95 (d) x 53mm (h)
• CONTACT: Crazy Tube Circuits

Usability and sounds

Using an all-analogue JFET circuit, it does a great job of delivering that Brit amp flavour. Juxtaposition of the Volume and Master knobs runs the gamut from glassy cleans through the various levels of break-up and crunch, to the distorted roar associated with a Marshall stack at full pelt.

The three different models that are represented here give you a valid set of alternative tonal choices. In increasing order of the gain available, you get a JTM45, a 1959 Super Lead, and a late-’70s JMP 2203 Master Volume model (same as a JCM800).

In addition to this you get the pedal’s secret sauce, the ‘Wall of Sound’ (WoS) switch, which – via a touch of extra output and some judicious EQ – delivers an uncanny impression of multiple amps.

The boost section recreates the preamp and dynamic expansion circuit of the Schaffer-Vega Diversity System that added an extra component to Angus Young’s tone.

Keep it turned on if that’s what you’re after, but there’s up to 15dB of clean boost, which is plenty for an extra-switchable element to the amp sounds for lead breaks or used independently to add some hair to your amp.

That boost is coloured by the Enhance knob, which, with quite subtle changes over its travel, works on dynamic and harmonic components to offer a certain enrichment to the sound, which you can dial in to taste.

Verdict

Verdict: ★★★★½

Guitar World verdict: Anyone looking for those Angus Young tones will find a shortcut straight to them via the Heatseeker, which can be easily set up to match any amp with its impressively flexible tone section, or connected to a DAW for recording (add your own speaker simulation). Whether you’re an AC/DC fan or not, there are some classic tones to be found within this little box of rock.

Hands-on videos

Pete Thorn

AndyDemos

The Studio Rats

Lets Play All

• “It has an obvious appeal to Gilmour fans… authentic-sounding Hiwatt tones from clean to everything-on-10 crunch”: Crazy Tube Circuits Hi Power review