The HP-X is a versatile distortion pedal inspired by the harmonic percolator. Whether you are searching for a harmonic-rich low gain overdrive distortion or a pedal that can achieve blown out gated fuzz tones, the HP-X is a solid choice for all types of rock music. The pedal captures the signature even-order overdrive of the original harmonic percolator without compromising stability or volume and has variable input impedance so it sounds great anywhere in your signal chain.
Stick to the Basics
While other versions of the percolator circuit have a ton of knobs, switches and other options, the HP-X sticks to the basics and offers the traditional two controls plus a clipping selection switch. Despite its simplicity, this pedal is extremely versatile with a wide variety of tones that range from overdrive to distortion to fuzz with many versions of each in between. Whatever the settings, the HP-X always sounds aggressive, punchy and has plenty of output.
Silicon and Silicon
We A/B’d a ton of silicon transistors to replace the germanium transistor from the original circuit. Yes, this percolator has a silicon transistor instead of a germanium transistor in the PNP position. Both of the silicon transistors that make up the circuit are measured and carefully selected so the circuit biases right every time. There are no compromises in sound here. In fact, we like this version the best!
The good news is you don’t have to worry about all the weirdness that might come with germanium and know this pedal is going to sound the same every time you kick it on regardless of temperature and playing conditions.
Still Has the Mojo
The HP-X features a specially selected combination of silver mica/poly film/ceramic capacitors that just get that clear and present but warm sound that we were going for with this percolator.
Left Knob: Harmonics
The left knob is the input level, turn left for less and right for more. Turning the knob to the right increases the compression, distortion and overall gating of the pedal from nice even=order overdrive to totally squished out gated fuzz. Adjust this knob to work with the pedal that comes before the percolator if it is later in the chain.
Right Knob: Balance
The right knob is the output volume, turn left for less and right for more.
Both knobs are highly interactive!
Clipping Options switch:
There are 3 clipping options on the HP-X:
Left: Asymmetrical Germanium Diode Clipping
Center: Diode lift for all transistor distortion
Right: Symmetrical Silicon Diode Clipping
The two diode clipping options were tweaked to have a similar volume output to one another while still retaining their unique clipping characteristics.