UralTone O Transforming Octave Fuzz Kit Build guide
UralTone O Transforming Octave Fuzz Kit Build guide
UralTone O-Transforming Fuzz is our version of the most legendary octave fuzz, the Tycobrahe Octavia. What makes this circuit unique is the use of an audio transformer in creating the upper octave. The transformer drives germanium diodes, which mix in an upper octave harmonic.
The circuit is very simple, producing a distinctive and recognizable raw Octave Fuzz sound, famously used by Jimi Hendrix.
Follow the assembly order in the images below. We strive to keep the component models consistent, but as the component market changes rapidly, we may sometimes need to switch suppliers or component series due to availability issues. If a component looks slightly different, don’t worry—each component is marked with the necessary values on its body.
Start the assembly with the footswitch. First, solder the LED resistor. This resistor is packed separately in the hardware set bag.Push the footswitch onto the PCB. Note the installation orientation: the notch in the threaded section should face upward. The PCB solder pads are tight, so the switch may require some force and persuasion. Be determined—the PCB and switch are sturdy enough to handle it.Cut five-centimeter pieces from the included wire. Strip about 3mm of insulation, twist the strands together, and pre-tin the stripped ends.
NOTE: Do not install the LED at this stage!Set the footswitch PCB aside and move on to the main effect circuit board.Start by cutting a thin copper strip from the switch connection pads.The thin copper strip can be easily cut with the tip of side cutters. The trace can be left intact if you choose not to install the octave switch.It is best to start assembly with the lowest-profile components. This way, the components remain flush with the PCB when flipped over for soldering. Continue by soldering the resistors onto the board. The resistance values are marked on the component body using color bands.Next, solder the diodes as shown in the image. Diodes have a specific installation direction. A stripe is printed on the diode body, and the PCB silkscreen provides corresponding markings.
NOTE: The glass diodes are germanium diodes. These are heat-sensitive, so avoid prolonged heating while soldering.Continue assembling the board by installing the ceramic and film capacitors. The ceramic capacitors in the image are tilted sideways for visibility—install them upright.Solder the electrolytic capacitors onto the board. These components have a specific installation direction. Align the white stripe on the component with the corresponding marking on the PCB.A side view of the electrolytic capacitors, showing their values.Solder the transistors as shown in the image. The installation direction is indicated on the PCB silkscreen, matching the shape of the transistor housing.Install the transformer in place.
NOTE: The "P" marking on the transformer should be oriented downward in the image / the black-colored side should be facing upward. Bend the transformer’s mounting legs outward to ensure a secure fit on the PCB.
(Note: The PCB shown in the image is an older version from this point onward.)Solder the potentiometers into place. First, solder one leg of the potentiometer and adjust its alignment if necessary. Once it is straight, solder the remaining two legs.
NOTE: Ensure that the potentiometer legs do not come into contact with the metal casing of the transformer.Solder the previously assembled footswitch PCB, battery clip, and octave switch. The battery clip wires can be shortened by approximately 5cm.Install the jacks into the enclosure. A star washer is placed between the enclosure and the jack.Insert the DC jack into the mounting hole.Insert the LED into its mounting hole. Pay attention to the LED's polarity. The shorter leg / beveled side is marked on the PCB. When viewed vertically (wires facing up), the beveled side / shorter lead should be on the left.This assembly is inserted into the enclosure.Install the boards into the enclosure. First, thread the battery clip wires under the output jack. Next, install the octave switch. Be careful when installing the effect board to prevent the DC jack from falling out of place. (You can keep it in place using an unpowered DC plug or a jack.) Optionally, install the front panel. Tighten the nuts by hand and align the board neatly. Once everything is positioned correctly, solder the DC jack. The LED is installed by pushing it through the front panel and soldering it in place. (Note: The PCB shown in the image is from a different circuit.)Solder the jack wires. (Note: The PCB in the image is an older version. No components should be soldered to the back of the board.)
NOTE: UralTone kits use two different types of input jacks. Check which version is included in your kit before soldering: https://en.uraltone.com/blog/input-jack/
Tighten the nuts on the front panel and attach the potentiometer knobs. The effect is ready to be tested!
Enjoy your playing!
If you have any questions or would like to provide feedback, please don't hesitate to contact us!
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UralTone O-transforming fuzz (aka Tycobrahe) - DIY KIT
