The Writ is a clone of the Ibanez Tube Screamer (TS9/TS808). This pedal has a characteristic mid-boosted sound that is popular with rock, metal, and blues styles of music. Noteable uses of the Tube Screamer include guitarist such as Stevie Ray Vaughan, Carlos Santana, and Billie Joe Armstrong. This clone is equipped with a Japanese Radio Company (JRC) 4558 operational amplifier.

Below you can see the Tube Screamer schematic with the primary amplifier being the JRC4558. Contrary to popular belief, the op-amp does not make or break the circuit. There are many people out there who believe that there is something special about how the design sounds, this simply isn’t true. The distortion from this circuit comes from soft clipping as a result of the diodes D1, D2, and D3 in the feedback section of the circuit. These diodes directly affect the type of distortion created. I used some 1N914 diodes in an asymmetrical configuration. This means the waveform is clipped unevenly giving the pedal a unique distortion sound. The 1N914A diode has about a 1V forward voltage. This is slightly lower than other diodes such as the 1N4004 with a forward voltage of 1.1V. This results in more clipping of the waveform.

I chose the same green design as the TS808. This pedal includes a true bypass 3P3T stomp switch. I later added a 9V DC jack, my original design did not include this. I etched the circuit board using toner transfer. This is a classic design and was not very difficult to build. See below for some more pictures of The Writ.