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.

The CD4040B is a 12-stage ripple-carry binary counter. All counter stages are master-slave flip-flops. The state of a counter advances one count on the negative transition of each input pulse; a high level on the RESET line resets the counter to its all zeros state. Schmitt trigger action on the input-pulse line permits unlimited rise and fall times.
$0.59

CD4047B consists of a gatable astable multivibrator with logic techniques incorporated to permit positive or negative edge-triggered monostable multivibrator action with retriggering and external counting options. Inputs include +TRIGGER, -TRIGGER, ASTABLE, ASTABLE\, RETRIGGER, and EXTERNAL RESET. Buffered outputs are Q\, Q and OSCILLATOR. In all modes of operation, and external capacitor must be connected between C-Timing and RC-Common terminal, and an external resistor must be connected between the R-Timing and RC-Common terminals. Astable operation is enabled by a high level on the STABLE input or a low level on the ASTABLE\ input, or both. The period of the square wave at the Q and Q\ Outputs in this mode off operation is a function of the external components employed. "True" input pulses on the ASTABLE input or "Complement" pulses on the ASTABLE\ input allow the circuit to be used as a gatable multivibrator.
$1.15

The CD4050B devices are noninverting hex buffers, and feature logic-level conversion using only one supply voltage (VCC). The input-signal high level (VIH) can exceed the VCC supply voltage when these devices are used for logic level conversions. These devices are intended for use as CMOS to DTL or TTL converters and can drive directly two DTL or TTL loads. (VCC = 5 V, VOL ≤ 0.4 V, and IOL ≥ 3.3 mA.) Features:
Applications
- Noninverting
- High Sink Current for Driving 2 TTL Loads
- High-to-Low Level Logic Conversion
- 100% Tested for Quiescent Current at 20 V
- Maximum Input Current of 1 µA at 18 V Over Full
- Package Temperature Range; 100 nA at 18 V and 25°C
- 5-V, 10-V, and 15-V Parametric Ratings
Applications
- CMOS to DTL or TTL Hex Converters
- CMOS Current Sink or Source Drivers
- CMOS High-to-Low Logic Level Converters
$0.75

CD4007UB types are comprised of three n-channel and three p-channel enhancement-type MOS transistors. The transistor elements are accessible through the package terminals to provide a convenient means for constructing the various typical circuits as shown in Fig. 2. More complex functions are possible using multiple packages. Numbers shown in parentheses indicate terminals that are connected together to form the various configurations listed. Features:
- Standardized symmetrical output characteristics
- Medium Speed Operation — tPHL, tPLH = 30 ns (typ.) at 10 V
- 100% tested for quiescent current at 20 V
- Meets all requirements of JEDEC Tentative Standard No.
$0.75

The CD4052B analog multiplexers are digitally-controlled analog switches having low ON impedance and very low OFF leakage current.
$0.89

The CD4013B device consists of two identical, independent data-type flip-flops. Each flip-flop has independent data, set, reset, and clock inputs and Q and Q outputs. These devices can be used for shift register applications, and, by connecting Q output to the data input, for counter and toggle applications. The logic level present at the D input is transferred to the Q output during the positive-going transition of the clock pulse.
$0.75

The CD4066B device is a quad bilateral switch intended for the transmission or multiplexing of analog or digital signals. It is pin-for-pin compatible with the CD4016B device, but exhibits a much lower on-state resistance. In addition, the on-state resistance is relatively constant over the full signal-input range. The CD4066B device consists of four bilateral switches, each with independent controls. Both the p and the n devices in a given switch are biased on or off simultaneously by the control signal. As shown in Figure 17, the well of the n-channel device on each switch is tied to either the input (when the switch is on) or to VSS (when the switch is off).
$0.59

CD4016B Series types are quad bilateral switches intended for the transmission or multiplexing of analog or digital signals. Each of the four independent bilateral switches has a single control signal input which simultaneously biases both the p and n device in a given switch on or off. Features:
- 20-V digital or ± 10-V peak-to-peak switching
- 280- typical on-state resistance for 15-V operation
- Switch on-state resistance matched to within 10 typ. over 15-V signal-input range
- High on/off output-voltage ratio: 65 dB typ. @ fis = 10 kHz, RL = 10 k
- High degree of linearity: <0.5% distortion typ. @ fis = 1 kHz, Vis = 5 Vp-p, VDD–VSS
- Extremely low off-state switch leakage resulting in very low offset current and high effective off-state resistance: 100pA typ.
$0.65

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.
$1.70

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.
$12.00
Out of Stock

Package of 5
Zero ohm (0Ω) resistors in a carbon film axial package. These resistors are a similar size to most common 1/4W carbon film and metal film resistors. Zero ohm resistors are useful as pcb jumpers as well as point to point jumpers. These can also be useful for true bypass 3PDT wiring.
$0.45

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

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)
$0.15

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
$16.95

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.
$0.39

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.

This small PCB is a simple way to add an indicator light that pulses to the rate of LFOs and clocks used in pedals, synthesizers, and other equipment. Simply connect the positive supply voltage to V+, ground to GND, and the output of a positive signal (0 to V+) such as an LFO or clock to the IN pad. The trimmer can adjust how the LED reacts to the signal. Fully clockwise it will simply pulse on and off when paired with a strong signal. If the signal is a sine, triangle, or any other non-pulse type signal, adjusting the trimmer counter clockwise can dial in settings that follow the shape of the waveform, brightening and dimming with the changing voltage. For certain dual op-amp LFOs in effect pedals, the signal may not go low enough to turn the LED fully off.
$0.70

Colors Available:
Starting at $1.39

Colors Available:
- High-quality 1.6mm FR4 glass-epoxy circuit board
- 1oz/ft2 copper weight
- HASL coated square shaped pads
- 20 x 10 holes
- 3.04” x 1.55”
$2.99

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.
Starting at $12.95

Genuine Switchcraft ⅜” knurled nut commonly used on ¼” jacks. This nickel plated knurled nut has a ⅜”-32 threading and offers a clean look on builds using these nuts. The ⅜”-32 threading fits other hardware with matching threading such as CTS potentiometers.
$0.99

Dual low power opamps in an 8-pin DIP package. The TL062 offers a high input impedance and 1MHz bandwidth.
$0.33

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

Colors Available:
$1.85