Interfax Harmonic Percolator ® 2021 Brown / Tan

Harmonic Percolator Exact physical and electrical duplicate.

 The Harmonic Percolator ®   is a distortion pedal that was made in Milwaukee, Wisconsin in the 1970's. It used a silicon NPN transistor and a germanium PNP transistor in a design that passes even order harmonics while suppressing odd order harmonics. These even order harmonics are more pleasing to the ear than odd order harmonics. It works surprisingly well with multiple notes.


 This is the original circuit, not someone’s interpretation of it. It is a discreet transistor complimentary Darlington circuit (Sziklai pair) different than any other fuzz / distortion pedal. There are at least four original versions of the Harmonic Percolator and this version is by far the best sounding. The left slider is the input gain or distortion control and the right one is the Balance control. The input is on the left and the output is to the right when looking down on it. This is opposite pedals of today but in its time this made sense. Left to Right - the same way you read.

 This handmade duplicate of the original 1970's pedal employs the same obsolete number Germanium transistor, not a common reproduction. New old stock 2N404A's are very hard to find and the market for fake knock off electronic parts is very large.  Same Silicon transistor. The silicon transistor was potted in the originals to discourage people from reading the number on it. It was a Fairchild 2n3565. Also used are the exact same number obsolete Germanium diodes.  Same type capacitors also are used. Mylar, Silver Mica, Tantalum, and Ceramic.

 The slider controls are the same as used in the original. These New Old Stock parts have the original packing slip dated February 19, 1968. New sliders are unavailable but if you stomp one to death contact me as I have replacements. We offer free lifetime repairs on your Harmonic Percolator so you never end up with a lemon.

Three original pedals were dismantled to help create this duplicate. One Percolator was totally dismantled, all its parts removed and measured. (Thanks John D. Greg K. Rusty B. at Rockhaus Guitars and Jay T. for trusting your pedals to me!). I am sure it was unsettling for the one original Percolator owner to have his pedal dismantled, the transistor removed AND heated up to about 150 degrees to loosen the wax holding the metal ring obscuring the part number. There are no hidden parts, no mis-labeled components, nothing unusual beyond the circuit itself.

 At low settings the Harmonic Percolator will give you greatly added sustain without 'coloring' your sound. Higher settings will give a mean distortion that performs well with multiple notes. These duplicates are in the exact same case and finished with a super tough powder coating in the original tan and brown style.

This is a faithful duplication of the effects pedals created by Ed Giese of Interfax Electronics in Milwaukee Wisconsin during the 1970's. The term Harmonic Percolator ® has been trademarked. I am happy to be able to provide a genuine product and also to protect the name from incorrect circuit representations.

I do not have a sound file or Youtube video of this pedal. MP3's and videos are compressed. There is little to gain from a file format that strips away the highs and lows and then uses a codec to compress the sound. I feel it is not possible to compare sonic quality by listening to internet audio and videos.

True bypass switching! An exact piece of classic effects down to the photo duplicate circuit board.