Synth & Eurorack Parts / DIY

Our Synth & Eurorack Parts / DIY category is a curated list of items that are commonly found in synth/eurorack projects. The items and filters here do not represent our full lineup of parts. If you don't see what you are looking for, check out our main categories or send us a suggestion and we'll look into adding it.
Integrated Circuit - SSI2164, Quad VCA, Sound Semiconductor
The FatKeys™ SSI2164 is perhaps the most flexible VCA available, with four independent channels for lowest cost-per-VCA. The user-selectable mode control allows Class A, AB, or intermediate biasing, and current inputs and outputs provide great design freedom. Ideal for voltage-controlled filters. The SSI2164 is a versatile VCA building block for high-performance audio applications. Four independent channels provide voltage control of current-mode inputs and outputs for a gain range from +20dB to –100dB, with control provided by a ground-referenced –33mV/dB constant. The SSI2164 will directly retrofit existing SSM/V2164 positions while offering improvements that include significantly lower overall distortion, on-chip protection against asymmetrical power failure, and a substantial increase of input current handling. The device offers considerable flexibility for a wide range of design goals and applications.
Potentiometer Adapter Sleeve - Converts .125” shaft to ¼"
This nickel-plated brass adapter sleeve converts a 0.125 in. (3.17mm) shaft potentiometer to ¼" shaft (6.35mm), allowing for ¼" knobs to be used on a wider range of potentiometers. The cutout on the sleeve allows the set screw of the knob to secure directly to the shaft of the pot. Depending on the knob used, a longer set screw can be required.
Op-Amp - LM833, Dual, Low Distortion, Audio, 8-Pin DIP
LM833 dual op amp in an 8-pin dip package. The LM833 is a dual general purpose operational amplifier designed with particular emphasis on performance in audio systems. This dual amplifier IC utilizes new circuit and processing techniques to deliver low noise, high speed and wide bandwidth without increasing external components or decreasing stability. The LM833 is internally compensated for all closed loop gains and is therefore optimized for all preamp and high level stages in PCM and HiFi systems. The LM833 is pin-for-pin compatible with industry standard dual operational amplifiers. Features
  • Wide dynamic range: >140dB
  • Low input noise voltage: 4.5nV/ √ ^Hz
  • High slew rate: 7 V/μs (typ); 5V/μs (min)
  • High gain bandwidth: 15MHz (typ); 10MHz (min)
  • Wide power bandwidth: 120KHz
  • Low distortion: 0.002%
  • Low offset voltage: 0.3mV
  • Large phase margin: 60°
Transistor - JFET N-Ch Transistor Lo Freq / Lo Noise, PF5102
PF5102 N-Channel Switch (TO-92 package) - designed for low level analog switching, sample and hold circuits and chopper stabilized amplifiers.
  • Max drain to gate voltage = 40 V
  • Max gate to source voltage = -40 V
  • Max forward gate current = 50 m
Knob - Davies, 1400, Daka-ware, Small, Pointer
Colors Available:
High-quality USA made knobs from Davies Molding. The small 1400 pointer knob is made of solid phenolic and features a fine ridged grip with a distinctive point. This classic knob has been used on a variety of guitar pedals and audio equipment such as the Pultec EQP-1A.
  • Height: 0.38 in.
  • Length: 0.84 in.
  • Fits ¼" shaft with set screw
Starting at $1.75
Nut - Switchcraft, Dress Nut / Sealing Nut, ⅜”-32 UNEF-2A
Switchcraft shouldered hex nuts for ⅜”-32 UNEF-2A threaded bushings. These nuts include a rubber grommet for use in sealed systems and also add a unique look to any build such as pedals or amplifiers. The large nut (W-SC-DRESS-1) is intended for panel or chassis thicknesses of 0.05” through 0.09”. The small nut (W-SC-DRESS-2) is intended for panel or chassis thicknesses of 0.095” through 0.125”. Rubber grommet included.
Starting at $2.49
Switch - Carling, Mini Toggle, SPDT, 2 Position, Solder Lugs
Carling, SPDT mini toggle, 2 positions, ¼" mounting hole diameter, 0.354" bushing length.
Knob - Rogan, PT Series, 1P, Small, Pointer, Knurled Shaft
High-quality USA made knobs from Rogan Corp. These small pointer knobs from Rogan’s PT Series feature a soft rubber grip molded over a solid polymer knob. PT Series knobs can be found on synthesizer modules from Make Noise, Mutable Instruments and others. Fits 6mm T18 knurled shafts.
  • Height: 0.55 in.
  • Diameter: 0.45 in.
  • Fits T18 Knurled Shafts

For a D-shaft version of this knob, see P-K281P-W. A variety of different sizes are available from the PT Series. See the links below for the full selection of knurled shaft knobs from this series. P-K271PS-W 1PS Small Skirted Pointer P-K272P-W 2P Medium Pointer P-K272PS-W 2PS Medium Skirted Pointer
BreadBoard - Solderless, 400 point pattern
Solderless (plug-in) breadboard with 400 connection tie-points (i.e. 400 wire insertion holes) and 4 power rails. Solderless breadboards are great for building and testing new circuits because parts can be easily inserted and removed making them completely re-usable. This breadboard has a 300 tie-point IC-circuit area plus four 25 tie-point power rails. The housing is made of white ABS plastic, with a printed legend giving numbers and letters for columns and rows. The internal contacts are phosphor bronze with a plated nickel finish and a peelable adhesive tape backing is provided for attaching it to a surface. Be sure to check out the Zipwire™ jumper wire kits for use with this breadboard.
Transistor - MPSA14, Darlington, 500mA, 30V, NPN
MPSA14 NPN Darlington transistor (TO-92 package) - designed for high gain, low noise general purpose amplifier applications.
  • Max collector to emitter voltage = 30 V
  • Max collector to base voltage = 30 V
  • Max emitter to base voltage = 10 V
  • Max collector current = 0.5 A (continuous)
Switch - Carling, Submini Toggle, DPDT, 2 Position, PC Pins
Carling submini toggle switch, DPDT, 2 position, .195" mounting hole diameter, 0.236" bushing length.
LED Lens - Fresnel, Polycarbonate, 5mm
Colors Available:
Panel mount led lenses made of high quality polycarbonate. These lenses provide a clean semi-flush appearance with a small panel footprint and work well in any project using LED indicators. Features:
  • ¼” mounting hole
  • For panel thicknesses of 1/16” to ⅛”
  • Fresnel lens
  • Low Profile
Starting at $0.59
Transistor - 2N404A, Germanium, TO-5 case, PNP
2N404A PNP germanium transistors. 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. For a lower voltage version of this transistor, see P-Q2N404.
Heat Shrink - ¼" Diameter x 6" Long, 23 Pieces
Package of 23
The shrink ratio on this tubing is 2 to 1, it is fungus resistant and non-corrosive. It is recommended for tightly sealing connectors, terminals, wire splices, and tool handles. It may be shrunk with heat guns, oven, etc. Comes in 6 inch lengths, quantity of 23.
Potentiometer - Alpha, Reverse Audio, 9mm, Vertical, 50KΩ
Reverse audio taper (antilog), vertical mount, Alpha pots with a 6.35mm shaft diameter. These 9mm pots are poplar in DIY guitar pedals, synthesizers, and other projects. Mounting nut and washer included.
Potentiometer - Song Huei, Audio, 9mm, Tall
Audio taper, vertical mount, Song Huei pots with a 6mm shaft. These 9mm pots are popular in DIY guitar pedals, modular synthesizers, and other projects where space is limited. The knurled shaft features a painted indicator line so no knob is required. These tall versions have a 17mm shaft length and a total height of 25mm. For linear taper versions, see R-VSHL-BX. For center notched, linear taper versions, see R-VSHL-BX-CN.
Op-Amp - AS301AH, Alfa, Single, TO5-8 case
The AS301AH is Alfa’s version of the LM301A in an 8 pin TO5 package. The AS301A is a general purpose operational amplifier. This amplifier offers many features which make its application nearly foolproof: overload protection on the input and output, no latch-up when the common mode range is exceeded, and freedom from oscillations and compensation with a single 30 pF capacitor. It has advantages over internally compensated amplifiers in that the frequency compensation can be tailored to the particular application. For example, in low frequency circuits it can be overcompensated for increased stability margin. Or the compensation can be optimized to give more than a factor of ten improvements in high frequency performance for most applications. In addition, the device provides better accuracy and lower noise in high impedance circuitry.
Screw - M3, Nickel, Combination Head, Binding, 6mm
Package of 5
Combination Drive, Nickel, 6mm, M3 metric, zinc. Designed to go through a hole or nut that is pre-tapped to form a mating thread for the screw. Phillips drive is the most common drive used and is designed to "camout" when the screw reaches optimum tightness, thus preventing damage to the screw head.
Regulator - LM317T, Adjustable Output, 1.5A, Linear Voltage Regulator
Linear regulator with an adjustable voltage range from 1.2V to 37V. This regulator can supply 1.5A of current making it a great option for power supplies.
Transistor - AS394CH, Matched Pair, Alfa, TO5-8 case, NPN
The AS394CH 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.
Diode - 1N34A Germanium, low leakage
The 1N34A Germanium diode is an old standby in electronics. Widely used for detecting the rectifying efficiency or for switching on a radio, TV or stereo etc.
Dress Nut - Befaco, Bananuts, for 3.5mm Jacks
Colors Available:
Bananuts are anodized aluminum custom minijack nuts following Buchla/Serge coloring code: blue, purple, red, orange, yellow, white, green and black. These nuts are great for color-coding jacks or color-theming modules. Sold individually.
Nut - CTS, 3/8-32, Nickel, for 450 Series Potentiometers
Replacement nut for CTS 450 series potentiometers and others.
  • 3/8-32 threading
  • Sold individually
Potentiometer - Alpha, Audio, Solid Shaft, 16mm, Dual, 100kΩ
100kΩ dual-gang 16mm potentiometers with a solid shaft and an audio taper. These pots have solder lug terminals. The smaller size is useful for builds with limited panel space such as guitar pedals, synthesizer modules, and adding modifications to equipment. Washer and nut included.
  • Threading: M7 x 0.75
  • Distance between terminals: 5 mm (0.197”)
  • Bushing Length: 6.5mm (0.256")
  • Shaft Diameter: 6.35mm ( 0.250")
  • Taper: Audio (Log)