Akashic Guitar effects circuit lookup

1590B

From the post

The Park Fuzz Sound is a variant of the Tonebender Mk3. Sola Sound sold their own Sola Sound Tonebender Mk3, but that circuit or a variant of it made its way into a variety of pedals that were branded differently. Sola Sound built (or were suspected of building) the Bell Electrolabs Fuzz, Carlsbro Fuzz, CSL Super Fuzz, Park Fuzz Sound, Rotosound Fuzz, and the Vox-branded Tonebender Mk3. These were all variations of the same 3-transistor fuzz circuit. For the most part, all Mk3 variants have three knobs - a Volume control, a Fuzz control, and for the first time in the Tonebender series, an added Tone control. The Park Fuzz Sound is unique in that there was also a 2-knob version that was still based around the same Mk3 circuit. Unlike other 2-knob fuzzes of the era which tended to have a Volume and a Fuzz control, the 2-knob Park Fuzz Sound has a Volume and a Tone control, and is wired as if the Fuzz control is internally set to the max. This layout is for the 2-knob variant of the Park Fuzz Sound, which is great for a compact build in a 1590B. The Park Fuzz Sound can be picky about which transistors are used. Three are included in the BoM below, but you may need a larger batch of transistors you can try out in the circuit. The build pictured here uses transistors with the measurements seen in the below table. These were taken with a Peak Atlas DCA75 at room temperature. There are many transistor arrangements that will work, but that above transistor set sounds great and may give you something to aim for. Note that the DCA75 reads 0 leakage for anything below 10uA, but those should be considered ballpark values given how sensitive germanium transistors can be to temperature. This is a PNP build and uses battery power only. With no LED indicator, this pedal will last a very long time on battery power. If you would like to build this pedal with a DC jack, please see our PNP "Positive Ground" Pedal Considerations tech article. See Figure 4 in our Guitar Pedal Footswitch and Jack Wiring article for the recommended footswitch and I/O wiring.

Schematic

This is a board layout, a drawing of where each part goes, and the post may link the schematic it was drawn from. Open the layout at Amplified Parts. No KiCad fragment has been drawn for this circuit yet.

Parts list 15 rows

Report a wrong parse

Got parts in a drawer? See what you can build with them.

RefValueNormalizedTypeNotes
Resistors 6
×13.3k3.3kCarbon Comp Resistor(R-I3D3K)
×510k10kCarbon Comp Resistor(R-I10K)
×118k18kCarbon Comp ResistorAlternatively, use 1× R-I22K and 1× R-I100K in parallel for 18 kΩ; (R-I20K)
×1100k100kCarbon Comp Resistor(R-I100K)
×1470k470kCarbon Comp Resistor(R-I470K)
×1680k680kCarbon Comp Resistor(R-I680K)
Capacitors 5
×110uF10uElectrolytic(C-SA10-25)
×225uF25uElectrolytic(C-SA25-25)
×12.2nF2.2nFilm Cap(C-MD0022-630)
×2100nF100nFilm Cap(C-MKT-D1-400)
×1200pF200pSilver Mica Cap(C-SM220)
Diodes 1
×11N601N60Germanium Diode(P-Q972)
Transistors 2
×12N5272N527PNP Germanium TransistorQ3; (P-Q2N404A)
×2OC46OC46PNP Germanium TransistorQ1, Q2; (P-QOC46)
Potentiometers 1
×2B100kB100kPotentiometer(R-VAM100KL-SS)