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.
Op-Amp - LF347, Quad, Wide Bandwidth, 14-Pin DIP
LF347 quad op amp in a 14-pin DIP package. The LF347 is a low cost, high speed quad JFET input operational amplifier with an internally trimmed input offset voltage ( BI-FET II™ technology). The device requires a low supply current and yet maintains a large gain bandwidth product and a fast slew rate. In addition, well matched high voltage JFET input devices provide very low input bias and offset currents. The LF347 is pin compatible with the standard LM348. This feature allows designers to immediately upgrade the overall performance of existing LF348 and LM324 designs. The LF347 may be used in applications such as high speed integrators, fast D/A converters, sample-and-hold circuits and many other circuits requiring low input offset voltage, low input bias current, high input impedance, high slew rate and wide bandwidth.
Knob - Pointer, Small, Knurled, 0.675” Diameter
Colors Available:
This vintage knob design has been used on numerous boutique pedals. These classy knurled pointer knobs feature a slotted set screw, and fit ¼" solid shaft potentiometers. These are a close match to the Davies 1400.
  • Height: 0.43 in.
  • Length: 0.825 in.
  • Fits ¼" shaft with set screw
Knob - Aluminum, Set Screw, Diamond Knurl, 0.496” Diameter
Colors Available:
Anodized aluminum knob with channeled indicator line and set screw. This slim, solid aluminum knob has a diamond knurled grip with a diameter of 0.495”. It also features a counterbore which allows it to hide pot bushings for a clean look. Fits ¼” (6.35mm) pot shafts.
  • Height: 0.56 in.
  • Diameter: 0.496 in.
  • Fits ¼" shaft with set screw
Knob - Davies, 1700, Daka-ware, Pinched
High-quality USA made knobs from Davies Molding. The Davies 1700 is made of solid phenolic and has a classic style that fits nicely on any piece of equipment. The 1700 can be found on vintage radios and amplifiers, most notably the Filmosound projector amps that are popularly converted to guitar amplifiers.
  • Height: 0.59 in.
  • Diameter: 0.75 in.
  • Fits ¼" shaft with set screw
Transistor - BD139, Medium Power, TO-126 case, NPN
The BD139 is a NPN medium power BJT transistor in a TO-126 package. The BD139's typical applications include audio amplifiers and drivers but is also popularly used in silicon fuzz pedals. The BD139 is available in two different gain ranges: BD139-10 and QBD139-16. Type hFE (IC=150mA, VCE=2V) BD139-10 63-160 BD139-16 100-250
Starting at $0.49
Transistor - BC183, General Purpose, TO-92 case, NPN, Gain Sorted
The BC183 is a general purpose NPN transistor in a TO-92 case. The BC183 is commonly used in fuzz pedals and has a reputation as a warm sounding silicon transistor for fuzz. The BC183 is available in three different gain ranges: BC183A, BC183B, and BC183C. Type hfe (IC=2mA, VCE=5V, f=1KHz) BC183A 125-260 BC183B 240-500 BC183C 450-900
Starting at $0.25
Transistor - BC337, General Purpose, TO-92 case, NPN
The BC337 is a silicon general purpose NPN transistor in a TO-92 package. The BC337’s typical applications include signal processing, amplification, and switching. The BC337 is available in three different gain ranges: BC337-16, BC337-25, and BC337-40. Type hFE Range (IC=100mA, VCE=1V) Typical hFE (IC=100mA, VCE=1V) BC337-16 100-250 160 BC337-25 160-400 250 BC337-40 250-630 400
Transistor - BC108, TO-18 case, NPN
BC108 NPN silicon transistors. The BC108 is a popular NPN choice for fuzz pedals and other effects such as vintage silicon Fuzz Face builds and Big Muff clones. Type hFE (IC=2mA, VCE=5V) hfe (IC=2mA, VCE=5V, f=1KHz) BC108A 110-220 125-260 BC108B 200-450 240-500 BC108C 420-800 450-900
  • NPN polarity
  • Collector emitter breakdown voltage 25V
  • Collector base breakdown voltage 30V
  • Collector current 200mA
  • Power 0.75W
  • Transition frequency 150MHz
  • TO-18 case
  • Weight 0.35g
Transistor - MPSA18, Darlington 200mA 45V NPN
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)
Reverb Module - Accutronics Belton, Digi-Log, Adjustable Decay
A great digital reverb sound that easily replaces a spring reverberation unit. Stereo outputs may be summed for mono operation. Simple interface: input, output, +5V, and ground
Transistor - 2N3704, Silicon, TO-92 case, NPN
The 2N3704 is a general purpose silicon NPN transistor in a TO-92 case. The 2N3704 is primarily intended for general purpose amplification and switching applications.
3.5mm Jack - Qingpu, Eurorack, Stereo, PC Mount
PCB mounted 3.5mm stereo jacks commonly found in DIY Eurorack projects. These are the newest version from Qingpu Electronics featuring a square bushing plate for added durability. Hardware sold separately. See accessory items below.
Integrated Circuit - DAB2140, Multi-Mode VCF, Sound Semiconductor
The Sound Semiconductor DAB2140 is a pre-soldered DIP converter for the SSI2140. This board features the SSI2140 and two decoupling caps for the V+ and V- inputs. The pinout is labelled on the board and matches the SSOP pinout. This adapter features a 20 pin DIP base with a .600 in. width. The pins are standard male headers so 2.54mm female headers are recommended for socketing the board. For the SSOP version, please see P-Q-SSI2140. A refresh of a classic design, the FatKeys™ SSI2140 preserves mojo of the beloved SSM2040 and adds temperature compensation of gm cells and the exponential control port. A "Q VCA" is provided to allow easy resonance control as well as various options for Q compensation.
Trimmer - Bourns, 3362P, Single Turn, Top Adjust, PCB Mount
High-quality Bourns 3362P trimpots. These single-turn cermet trimmers can be found in countless guitar pedals and synthesizer modules. Sealed trimmers are built with an o-ring seal to prevent entrance of moisture and serve as a mechanical restraint to prevent unwanted wiper movement. ±10% tolerance.
Reverb Module - Accutronics Belton, Digi-Log, horizontal mount
A great digital reverb sound that easily replaces a spring reverberation unit. Simple interface requires only input, output, +5V, and ground. Output requires no external capacitors.
Transistor - 2N1711, Silicon, TO-39 case, NPN
The 2N1711 is a silicon planar epitaxial NPN transistor in a TO-39 metal case. It is intended for use in high performance amplifiers, oscillators and switching circuits. The 2N1711 is a great choice for amplifiers where low noise is an important factor.
Op-Amp - TL062, Dual, Low-Power, JFET Input, 8-Pin DIP
Dual low power opamps in an 8-pin DIP package. The TL062 offers a high input impedance and 1MHz bandwidth.
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.
Knob - Aluminum, Set Screw, Short Line, 0.495" Diameter
Colors Available:
Anodized aluminum knob with short indicator line and set screw. This slim, solid aluminum knob has a straight knurled grip with a diameter of 0.495”. It also features a counterbore which allows it to hide pot bushings for a clean look. Fits ¼” (6.35mm) pot shafts.
Power Jack - Lumberg, DC Panel Mount, Low Profile, 5.5mm External, 2.1mm Internal
Low profile Lumberg panel mount barrel jack with solder lugs. This high quality jack is the perfect size for smaller builds where additional space is necessary. The Lumberg low profile DC jack is also great for builds where aesthetics are a priority. For use with barrel plugs with a 5.5mm external diameter and 2.1mm internal diameter. Mounting nut included.
Op-Amp - LF356, Single, High Slew Rate, 8-Pin DIP
LF356 single op amp in an 8-pin DIP package. The LFx5x devices are the first monolithic JFET input operational amplifiers to incorporate well-matched, high-voltage JFETs on the same chip with standard bipolar transistors (BI-FET™ Technology). These amplifiers feature low input bias and offset currents/low offset voltage and offset voltage drift, coupled with offset adjust, which does not degrade drift or common-mode rejection.
PadBoard - Double Sided, Plated Holes, 6.30” x 3.94”, Mounting Holes
The PadBoard-3U prototyping circuit board has a general purpose pad-per-hole pattern which is good for general purpose analog and digital use. It is a double-sided board with plated holes, which allows components to be soldered to either side of the board. A square pad is provided every 5th hole, which makes it easy to align components on the top and bottom of the board. The PCB accepts a 96 pin DIN-41612 VME connector for backplane or board-to-board applications. Holes for ejector latches are provided. Features
  • Pad-per-hole prototyping board with plated-thru holes. A square pad every 5th hole makes it easy to align components on top and bottom.
  • Double-sided high-quality FR4 glass-epoxy circuit board with plated holes. Components can be soldered to either side.
  • 1oz/ft2 copper with an anti-tarnish coating for easy soldering.
OTA - AS3080E, Linearizing Diodes, Alfa, 8-Pin DIP
The AS3080E is Alfa’s version of the CA3080 IC. The AS3080E is a gain block which is the operational-transconductance-amplifier (OTA). The AS3080E 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 AS3080E is notable for it’s high slew rate (50V/µs), which makes it especially useful for multiplexer and fast unity-gain voltage followers.
Felt Strip - 51.5", for Korg & Yamaha Keyboards
For Yamaha DX7, DX7 II, FX20, Korg M1, Trinity and T Series.