Pedal Parts / DIY

This is a set of two 2N1309 germanium transistors that have been hand-selected to work in the germanium Fuzz Face circuit. Also included are 4 metal film resistors to use in the circuit. In most cases, the values have been modified from the stock values slightly to ensure that the collector of Q2 biases to roughly -4.5V. A data sheet containing the schematic and the resistor values is included so that you can use your own resistor type if you would prefer. There is a range of bias voltages that can sound nice in a Fuzz Face, and voltages in original units varied. These transistors have been tested with bias voltage, sound, and noise level in mind. Note that due to a variety of factors such as battery/PSU voltage, temperature, and component tolerance, the voltage on the collector of Q2 may not measure at exactly -4.5V, but it should be close in a properly-built circuit.

2N5457 N-Channel JFET in a TO-92 package. The 2N5457 is designed primarily for audio and switching applications.

• Max drain to gate voltage = 25 V
• Max gate to source voltage = -25 V
• Max forward gate current = 10 mA

New old stock 2N3565 transistors manufactured by Micro Electronics. The 2N3565 is a silicon NPN transistor in a TO-106 case. The 2N3565 is primarily intended for general purpose and low level applications. 2N3565 transistors were used in the original Harmonic Percolator, Foxx Tone Machine and the Sam Ash Fuzzz Boxx.

New old stock 2N404A PNP germanium transistors manufactured by Texas Instruments. These TI 2N404A feature gold plated leads. The 2N404A is used in many fuzz pedals along with other effects. The 2N404A is the same as the 2N404 but with a higher voltage rating. This transistor is in a TO-5 package with long leads commonly found on germanium transistors.

SFT353 PNP germanium transistors. The SFT353 is a popular PNP for fuzz pedals and other effects. This transistor is in a 18B4 package with long leads commonly found on germanium transistors. This style of package can be found in Italian built Vox Tonebenders.

NTE103 NPN germanium transistors. The NTE103 is a popular NPN for fuzz pedals and other effects. This transistor is in a TO-5 package with long leads commonly found on germanium transistors. The NTE103 was used in the Texas Square Face made by Cesar Diaz, the famous amp tech who worked with Stevie Ray Vaughan and others. Early in his career, SRV had a broken Fuzz Face pedal and took it to Cesar Diaz to have him fix it. Diaz fixed and modified the pedal and this became the foundation of his famous version which he named the Texas Square Face. The Diaz pedals often came with socketed NTE103 and included a set of P-QNTE123 to experiment with the different sounds of the transistors.

NTE123 NPN silicon transistors. The NTE123 is a popular NPN for fuzz pedals and other effects. This transistor is in a TO-5 package. The NTE123 was used in the Texas Square Face made by Cesar Diaz, the famous amp tech who worked with Stevie Ray Vaughan and others. Early in his career, SRV had a broken Fuzz Face pedal and took it to Cesar Diaz to have him fix it. Diaz fixed and modified the pedal and this became the foundation of his famous version which he named the Texas Square Face. The Diaz pedals often came socketed and included a set of NTE123 along with the standard pair of P-QNTE103 to experiment with the different sounds of the transistors.

OC42 PNP germanium transistors. The OC42 is a popular PNP for fuzz pedals and boost effects. It can be found in vintage electronics and modern fuzz pedals. This transistor is in a black glass SO-2 package with long leads commonly found on germanium transistors.

OC83N PNP germanium transistors. The OC83N is a great PNP for fuzz pedals and boost effects. It is the TO-1 version of the OC83 which can be found in many fuzz pedals such as MK1.5 and MKII Tonebender clones. This transistor features long leads commonly found on germanium transistors.

2N2646 programmable unijunction transistor often referred to as a PUT. The 2N2646 can be found in many tremolo effects pedal projects and vintage classics such as the Vox Repeat Percussion.

BC148C NPN transistor in a rare Mullard Lockfit package. The BC148C is the equivalent of a BC108C but in the Lockfit package rather than a TO-18. The BC148C was used in a variety of audio and radio equipment and works well for fuzz and other effects.

OC41 PNP germanium transistors. The OC41 is a popular PNP for fuzz pedals and boost effects. It can be found in vintage electronics and modern fuzz pedals. This transistor is in a black glass SO-2 package with long leads commonly found on germanium transistors.

OC46 PNP germanium transistors. The OC46 is a popular PNP for fuzz pedals and boost effects. It can be found in vintage electronics and modern fuzz pedals. This transistor is in a black glass SO-2 package with long leads commonly found on germanium transistors.

SFT319 PNP germanium transistors. The SFT319 is a popular PNP for fuzz pedals and other effects. This transistor is in a 18B4 package with long leads commonly found on germanium transistors. This style of package can be found in Italian built Vox Tonebenders.

TI377 PNP germanium transistors from Texas Instruments. The TI377 is a great PNP for fuzz pedals and other effects. This transistor is in a metal SO-2 package with long leads commonly found on germanium transistors. This package with the gold leads visually matches the 2G308, 2G309, and 2G381 transistors found in Zonk and Tonebender MKI fuzz pedals.

AC132K PNP germanium transistors. The AC132K is a popular PNP for fuzz pedals and other effects. This transistor is in a thick rectangular heat-sink package with long leads commonly found on germanium transistors.

BC238B NPN transistor in a TO-92 package. The BC238 is used in a variety of vintage pedals such as the Schaller Fuzz, a version of the Brian May treble boost,and later Jen / Tonebender fuzz pedals. The BC238B is a variant of the BC108B and works well in other classic fuzz pedals such as Fuzz Face and Big Muff builds.

NPN Darlington transistor (TO-92 package) - designed for high gain, low noise general purpose amplifier applications.

• Max collector to emitter voltage = 45 V
• Max collector to base voltage = 45 V
• Max emitter to base voltage = 6.5 V
• Max collector current = 0.2 A (continuous)

2N1308 NPN germanium transistors. The 2N1308 is a popular NPN for fuzz pedals and other effects. This transistor is in a TO-5 package with long leads commonly found on germanium transistors.

The AS394H is a junction isolated ultra well-matched monolithic NPN transistor pair with an order of magnitude improvement in matching over conventional transistor pairs. Electrical characteristics of these devices such as drift versus initial offset voltage, noise, and the exponential relationship of base-emitter voltage to collector current closely approach those of a theoretical transistor. Extrinsic base and emitter resistances are very low, giving very low noise and operating over a wide current range. To guarantee long term stability of matching parameters, internal clamp diodes have been added across the emitter-base junction of each transistor. These prevent degradation due to reverse biased emitter current, the most common cause of field failures in matched devices.

High quality single row machine pin sockets made by Preci-Dip. These sockets are the break-away type and can easily snap into smaller sizes such as 5 separate transistor sockets.

The 2N5135 is a silicon NPN transistor in a TO-105 case. This transistor is a close match to the rare 2N5133 but with higher voltage ratings and is in a larger package. The hFE range is less wide than the 2N5133 with more values in the range found in the batches used on vintage Big Muff pedals. The lower hFE range also makes these a great option for silicon fuzz pedals.

The 2N4403 is a silicon general purpose PNP transistor in a TO-92 package. The 2N4403’s typical applications include signal processing, amplification, and switching.

2N321 PNP germanium transistors. The 2N321 is a popular PNP for fuzz pedals and other effects. This transistor is in a TO-5 package with long leads commonly found on germanium transistors.