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.
Switch - Carling, Mini Toggle, SPDT, 3 Position, Solder Lug
Carling mini-toggle switch, SPDT, Solder Lug, 3-Position, On/Off/On
$4.95
Switch - Carling, Mini Toggle, DPDT, 2 Position, PC Pins, Short Bat
Carling mini-toggle switch, DPDT, 2 position, ¼" mounting hole diameter, 0.354" bushing length.
  • 0.354" bushing length
  • 2-Position On/On
  • ¼" mounting hole diameter
  • Double pole/Double throw (DPDT)
  • PC mount pins
$4.95
Transistor - TI377, Germanium, SO-2 metal case, PNP
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.
$4.95
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.
$4.95
Switch - Carling, Mini Toggle, SPDT, 3 Position, Solder Lugs, Short Bat
Carling, SPDT mini toggle with short actuator, 3 positions, ¼" mounting hole diameter, 0.354" bushing length.
  • 0.354" bushing length
  • 3-Position On/Off/On
  • ¼" mounting hole diameter
  • Single pole/Double throw (SPDT)
  • Solder lugs
$4.95
Knob - Rogan, RB-67 Series, Large, Skirted
High-quality USA made knobs from Rogan Corp. These large knobs feature a metal insert, spun aluminum inlay, and a skirt with an infilled arrow indicator. The RB-67 Series from Rogan is popularly used on Buchla 200 Series modular synthesizers and can be found on many contemporary eurorack synthesizers.
  • Height: 1.02 in.
  • Diameter: 1.52 in.
  • Fits ¼" shaft with set screw

A variety of sizes and colors are available from the RB-67 Series. See the links below for the full selection of knobs from this series. P-K770-X Small P-K770S-X Small Skirted P-K771S-X Medium Skirted P-K772S-B Large Skirted
$4.95
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.
$4.95
Transistor - GT309E, Germanium, USSR Saucer Case, PNP
New old stock Soviet GT309E transistors manufactured in Ukraine. The GT309E is a germanium PNP transistor in a very low profile case. The case has a 0.29” diameter and is only 0.1” thick. These have very low leakage and work well in a variety of fuzz pedal builds.
$4.95
Switch - Carling, Mini Toggle, 3PDT
Carling mini-toggle switch, 3PDT, ideal for stomp boxes, phase switching, coil-tapping, series/parallel pickup switching in guitars.
  • 0.354" bushing length
  • 1/4" mounting hole diameter
  • On-On Three pole/double throw (3PDT)
$4.95
Transistor - J201, Siliconix, JFET, N-Channel, TO-92
J201 N-Channel JFET in a TO-92 package made by Siliconix. The J201 is designed primarily for low level audio and general purpose applications with high impedance signal sources.
  • Max drain to gate voltage = 40 V
  • Max gate to source voltage = -40 V
  • Max forward gate current = 50 mA
$4.95
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.
$4.95
Switch - Carling, Submini Toggle, SPDT, 2 Position, PC Pins
Carling submini toggle switch, SPDT, 2 position, .195" mounting hole diameter, 0.236" bushing length.
$4.95
Transistor - J201, JFET, N-Channel, TO-92
J201 N-Channel JFET in a TO-92 package. The J201 is designed primarily for low level audio and general purpose applications with high impedance signal sources.
  • Max drain to gate voltage = 40 V
  • Max gate to source voltage = -40 V
  • Max forward gate current = 50 mA
$4.95
Transistor - 2N1308, Germanium, TO-39 case, NPN
2N1308 NPN germanium transistors. The 2N1308 is a popular NPN for fuzz pedals and other effects. This transistor is in a TO-39 package.
$4.89
StripBoard - Single Sided, 3.94” x 3.15”, Mounting Holes
ST2 StripBoard is a prototyping circuit board with a standard long strip pattern. Tracks run the length of the board. The long tracks are convenient for power and ground rails, and for signal buses. Strips can be cut as needed to make smaller tracks and circuit pads. It has 0.1" hole spacing for DIP integrated circuits and headers and other parts. ST2 has higher quality than traditional stripboard. The holes are drilled, not punched. The base material is high-quality FR4 glass epoxy board. It has better stability and moisture resistance than boards using phenolic or SRBP (synthetic resin bonded paper), which can warp with exposure to humidity. Features
  • Standard stripboard pattern, with tracks running the length of the board.
  • Single-sided high-quality FR4 glass-epoxy circuit board.
  • 1oz/ft2 copper with an anti-tarnish coating for easy soldering.
$4.75
Breadboard - Solderable PCB, 3.75” x 1.85”, Mounting Holes
Solderable PC BreadBoard enables you to transfer your circuit and wires from a plug-in breadboard without recutting wires or changing your layout. This breadboard has the same pattern as a standard 400 connection point solderless plug-in breadboard which has a standard 5-hole strip for each IC pin, just like solderless breadboards. However, it has the advantage that soldered joints provide a more reliable long-term connection than solderless contacts. The board has four power rails like solderless breadboards, plus two bonus rails for power or signals. There are bonus two-hole pads along the centerline allowing DIL (dual in-line) headers to be used as well as a top side silkscreen to position components. Four mounting holes allow your projects to be secured.
$4.75
OTA - AS3080ED, Linearizing Diodes, Alfa, SOIC-8
The AS3080ED is Alfa’s version of the CA3080 IC in an SOIC package. The AS3080ED is a gain block which is the operational-transconductance-amplifier (OTA). The AS3080ED has differential input and a single-ended, push-pull, class A output. Amplifier bias input may be used either for gating or for linear gain control. High output impedance and transconductance (gM) is directly proportional to the amplifier bias current (IABC). Linearizing diodes are provided at the inputs to reduce distortion and allow higher input levels. The result is a 10-dB signal-to-noise improvement referenced to 0.5 percent THD.
The AS3080ED is notable for it’s high slew rate (50V/µs), which makes it especially useful for multiplexer and fast unity-gain voltage followers.
$4.75
Transistor - SFT353, Germanium, 18B4 case, PNP
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.
$4.65
On Backorder
Op-Amp - M5201, Dual, With Switch, 8-Pin DIP
The NJM2120 is a dual operational amplifier of 2-INPUT and 1-OUTPUT with analog switch. The NJM2120 can be used as analog switch under the condition of GV=0dB, as Switch + Amp in order that each gain (A or B) can be adjusted independently. Each amplifier of the NJM2120 has the same electrical characteristics as the NJM4558. The NJM2120 is suitable for audio, video, electrical musical instrument, etc.
$4.50
Transistor - AS194DE, Matched Pair, Alfa, SOIC-8, NPN
The AS194DE 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.
$4.50
Transistor - AS194H, Matched Pair, Alfa, TO5-8 case, NPN
The AS194H 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.
$4.50
Op-Amp - OP275, Dual, Bipolar/JFET, Audio, 8-Pin DIP
OP275 dual audio op amp in an 8-pin DIP package. The OP275 is the first amplifier to feature the Butler Amplifier front end. This new front end design combines both bipolar and JFET transistors to attain amplifiers with the accuracy and low noise performance of bipolar transistors, and the speed and sound quality of JFETs. Total Harmonic Distortion plus Noise equals that of previous audio amplifiers, but at much lower supply currents. A very low l/f corner of below 6 Hz maintains a flat noise density response. Whether noise is measured at either 30 Hz or 1 kHz, it is only 6 nVHz. The JFET portion of the input stage gives the OP275 its high slew rates to keep distortion low, even when large output swings are required, and the 22 V/µs slew rate of the OP275 is the fastest of any standard audio amplifier.
$4.50
Breadboard - Solderable PCB, 3.00” x 1.90”
The SB400 Solderable PCB BreadBoard enables you to transfer your circuit and wires from a plug-in breadboard without recutting wires or changing your layout. The SB400 has the same pattern and spacing as a standard 400 connection point BB400 solderless plug-in breadboard. It has a standard 5-hole strip for each IC pin, just like solderless breadboards plus 4 power rails. However, it has the advantage that soldered joints provide a more reliable long-term connection than solderless contacts. The SB400 has four power rails like solderless breadboards, plus two bonus rails for power or signals. There are bonus two-hole pads along the centerline allowing DIL (dual in-line) headers to be used. BPS prototyping boards use high-quality FR4 glass epoxy PCBs for long life, with an anti-tarnish protective coating for easy soldering.
$4.35
Tool - Slotted Nut Driver, for Qingpu Jacks
Simple and easy to use nut driving tool for the slotted nuts found on Qingpu jacks that are commonly used in Eurorack modules. The tool anchors into the sleeve of the jack ensuring no slippage when in use, protecting the faceplate from accidental damage. The two grip holes are cut to the size of M2.5 and M3 hex nuts and can be used in a pinch to tighten nuts of those sizes, or to hang your tool on a keyring! One side of the tool works with Mod "Top Brass" nuts and slotted W-QP-NUT-K nuts used on W-QP-518MA, W-QP-419GR, and W-QP-518MA-BM. The other side works with slotted W-QP-NUT-PJ-R nuts used on W-QP-PJ3410. Either side will work with Befaco Bananuts for 3.5mm jacks (W-BNUT-X). The nut driving tool is made of steel.
$4.30