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.
Knob - Plastic, Set Screw, Pinched w/ Line, 0.630" Diameter
Colors Available:
Small plastic control knob with set screw and metal insert. This knob has a pinched grip similar to the Davies 1510 but features a smaller diameter and scooped cutout for a distinctive appearance. Fits ¼” (6.35mm) pot shafts.
Starting at $0.85
Switch Accessory - Mini Toggle Caps, Standard Bat, 11 Colors
Colors Available:
Rubber caps / switch tips for mini toggle switches in a variety of colors. These are made for standard sized toggle bats. Available in 11 different colors.
Integrated Circuit - SSI2131, VCO, Sound Semiconductor
The FatKeys™ SSI2131 Voltage Controlled Oscillator provides the core VCO function with buffered triangle, sawtooth, and variable-width pulse waveform outputs over a ten-octave range. The device offers unparalleled temperature stability, exponentiality, waveform integrity, and ease of use while requiring an absolute minimum of external components. The SSI2131 is a new-generation voltage controlled oscillator for high-performance electronic musical instruments and other systems requiring accurate audio-band waveform generation. The device offers unprecedented levels of temperature stability, exponentiality, waveform integrity, and ease of use.
OTA - AS3280, Dual, Linearizing Diodes, Alfa, 16-Pin DIP
The AS3280 is Alfa’s version of the CA3280 IC. The AS3280 consists of two variable operational amplifiers that are designed to substantially reduce the initial input offset voltage and the offset voltage variation with respect to changes in programming current. This design results in reduced "AGC thump," an objectionable characteristic of many AGC systems. Careful design of critical places of the circuit reduces the amplifier dependence upon thermal and processing variables.
The AS3280 has all the generic characteristics of an operational voltage amplifier except that the forward transfer characteristics is best described by transconductance rather than voltage gain, and the output is current, not voltage. The magnitude of the output current is equal to the product of transconductance and the input voltage.
Diode - Silicon Rectifier, 3A, 400V, 1N5404
A semiconductor device which passes current in the forward direction(from anode to cathode), and blocks current in the opposite direction.
Resistors - ¼ Watt, Metal Film, 1% tolerance
Package of 5
Metal Film resistors consist of a resistive element of an extremely thin layer of metal alloy vacuum deposited on a substrate. Precise and quiet. Package of 5. These resistors are perfect for pedal builders! 1/4 watt.
Integrated Circuit - SSI2144, Ladder VCF, Sound Semiconductor
The second of two legendary SSM filter updates, the FatKeys™ SSI2144 is a dedicated four-pole low-pass ladder filter with on-chip resonance control. Original designer Dave Rossum did a number of performance updates such as lower noise, improved control feedthrough, and logical pin grouping but otherwise left this sweet-sounding VCF alone. The SSI2144 reprises the SSM2044 of legacy chipmaker Solid State Micro Technology, which many believe to be the best-sounding analog synthesis filter IC ever produced. Based on Dave Rossum’s patented classic improved ladder topology, the SSI2144 allows rich tonal characteristics that showcase the very best attributes of subtractive synthesis. The SSI2144 uses the same internal circuit as the SSM2044 but incorporates improvements by the original designer and takes advantage of modern process technology.
Potentiometer - Alpha, Linear, 9mm, Vertical, 11 Detents
Linear taper, vertical mount, Alpha pots with a 6.35mm shaft diameter featuring 11 detents across the rotation. The 11 detent versions are useful for builds where 1-10 settings are commonly used or if the pot is used as a rotary switch along with a microcontroller. These 9mm pots are popular in DIY guitar pedals, synthesizers, and other projects. Mounting nut and washer included. See R-VAV-A100K-11DET for an audio taper version.
Heat Shrink - Assorted Diameters, 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 as well as weather-proofing wire repairs. It may be shrunk with heat guns, oven, etc. Comes in 6 inch lengths.
Screws - M3-0.5 Button-Head Socket Cap, 8mm Long
Package of 5
Colors Available:
Button-Head Socket Cap Screws - Class 10.9, ISO 7380 Coarse Thread. Used when a wider bearing surface or smoother, more finished appearance is desired.
Starting at $0.75
Capacitor - 50V, 0.047µF, Used In Pedal Kits
Polyester Film Capacitor used in MOD® Pedal Kits. Rated at 0.047µF 50V. Tolerance: 10%. Operating temperature: -40 C to +85 C
Switch - Carling, Mini Toggle, DPDT, 2 Position, Solder Lugs, Short Bat
Carling mini-toggle switch, DPDT, 2 position, ¼" mounting hole diameter, 0.354" bushing length.
Transistor - 2N5087, Bipolar, General Purpose, PNP
2N5087 PNP Bipolar Junction Transistor in TO-92 package. For the NPN 2N5087 see P-Q2N5088
Power Jack - DC Panel Mount, 5.5mm External, 2.1mm Internal
Colors Available:
½" panel mount with solder lugs. Round plastic with normally closed switch. For barrel plugs with a 5.5mm external diameter and 2.1mm internal diameter.
Starting at $0.75
Potentiometer - Alpha, Audio, 9mm, Right Angle
Audio taper (log), right angle, Alpha pots with a 6.35mm shaft diameter. These 9mm pots are popular in DIY guitar pedals, synthesizers, and other projects. Mounting nut and washer included.
Knob - Plastic, Set Screw, MXR Style, 0.755" Diameter
Mid-sized black plastic control knob with set screw and brass insert. This knob is similar in appearance to the classic MXR knobs but with a smaller diameter. It features a fluted grip with an indicator line along with a small skirt with a dot indicator. Fits ¼” (6.35mm) pot shafts.
On Backorder
Transistor - AC127, Germanium, TO-1 case, NPN
AC127 NPN germanium transistors. The AC127 is a popular NPN for fuzz pedals and other effects. The NPN polarity allows for use with standard pedal power supplies.
Potentiometer Adapter Sleeve - Converts 6mm or 18T shaft to ¼"
This brass adapter sleeve converts a 6mm shaft potentiometer or 18T knurled shaft potentiometer to 1/4" shaft (6.35mm), allowing for 1/4" knobs to be used on a wider range of potentiometers. 1/4" tall.
Optocoupler - Xvive, Vactrol, VTL5C Series
High quality vactrols from Xvive. The Xvive vactrols are clones of the original Excelitas / Perkins-Elmer vactrols used in many effects pedals, synthesizers, compressors and other equipment. These vactrols feature a thick epoxy sealed casing. The VTL5C3 and VTL5C3/2 both have a steep slope, good dynamic range, a very low temperature coefficient of resistance, and a small light history memory.
Starting at $5.50
Integrated Circuit - AS3310, VC ADSR, Alfa, 16-Pin Dip
The AS3310 is Alfa’s version of the CEM3310 IC. The AS3310 is a self-contained, precision ADSR type of envelope generator intended for electronic music and other sound generation applications. Attack, decay and release times are exponentially voltage controllable over a wide range, and the sustain level is linearly voltage controllable from 0 to 100% of the peak voltage Vp. All four control Inputs are Isolated from the rest of the circuitry so that the control pins of tracking units may be simply tied together.
On the negative power output, there is an internal Zener diode at 7.4 volts ± 10%, which allows the chip to supply a maximum voltage of ± 15 volts with a current-limiting resistor REE, and a minimum positive supply voltage of + 11 volts and a minimum negative supply voltage of -5 volts.. A series current limiting resistor must be added between pin 6 and the supply.
Op-Amp - NJM4558, Dual high-gain, 8-Pin DIP
Dual Operational Amplifier. The NJM4558 (JRC4558) integrated circuit is a dual high-gain operational amplifier internally compensated and constructed on a single silicon chip using an advanced epitaxial process. Combining the features of the NJM741 with the close parameter matching and tracking of a dual device on a monolithic chip results in unique performance characteristics. Excellent channel separation allows the use of the dual device in single NJM741 operational amplifier applications providing density. It is especially well suited for applications in differential-in, differential-out as well as in potentiometric amplifiers and where gain and phase matched channels are mandatory. Features:
  • Operating Voltage (±4V~±18V)
  • High Voltage Gain (100dB typ.)
  • High Input Resistance (5MΩ typ.)
  • Bipolar Technology
LED - 3mm, Water Clear, High Brightness, Package of 5
Package of 5
Colors Available:
High brightness 3mm LED. Great for use in pedal builds and other applications where a bold, bright, indicator is needed. Multiple colors available.
  • 3mm size
  • Water clear
  • High brightness
  • Multiple colors available
  • Package of 5
Starting at $1.30
Integrated Circuit - SSI2162, Dual VCA, Sound Semiconductor
The FatKeys™ SSI2162 provides two independent VCA channels, and like its SSI2161 and SSI2164 siblings offers great flexibility in design of dynamics processors, automatic or remote level control, and voltage controlled filters. Highly compact 10-lead SSOP package. The SSI2162 is a versatile VCA building block for high-performance audio applications. Two independent channels provide voltage control of a current-mode input and output for a gain range from +20dB to –100dB, with control provided by a ground-referenced –33mV/dB constant. The device offers considerable flexibility for a wide range of design goals and applications. A unique mode control allows selection of Class A, Class AB, or in-between using a single resistor. In addition, improved current handling allows use of lower value input resistors for reduced output noise without loss of headroom. Both channels can be parallel-connected for further noise improvement.
Potentiometer - Alpha, Linear, 9mm, Vertical, Dual Gang
Linear taper, vertical mount, dual gang Alpha pots with a 6.35mm shaft diameter. Dual gang pots are useful for stereo controls and other circuits requiring two separate pots moving in tandem. These 9mm pots are popular in DIY guitar pedals, synthesizers, and other projects. Mounting nut and washer included. See R-VAV-A100K-DUAL for an audio taper version.