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Adsr

rabidaudio·synthesizer·adsr/adsr.kicad_pcb

Adsr PCB layout, top view — open source board by rabidaudio
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About the Adsr PCB

Adsr is an open source PCB design by rabidaudio, published on GitHub under the MIT license. It is a 2-layer board measuring 29.5 × 112.3 mm, with 72 components from 28 distinct parts.

Other key parts include the LM13700, TL074, DG403 and TL072. By type, the board carries 24 resistors, 14 connectors, 12 capacitors, 8 ICs, 6 transistors and 4 diodes.

It belongs with the audio designs in this gallery.

From the project

My custom synthesizer work

This circuit operates by using the LM13700 as a variable current source charging a capacitor. It is configured as a non-inverting op-amp charging the capacitor to a reference voltage Vref at the + pin with a slew rate limited by the current control. The capacitor's voltage will change linearly based on Iabc until it settles at Vref. Then a bit of digital logic to create a 3-state state machine to select the correct Vref and Iabc`.

Adsr, from the project README
From the project README

Main components on the Adsr

LM13700TL074DG403TL072

Adsr bill of materials (BOM)

72 components, 28 distinct parts.

QtyPartRefs
1
LM13700
U1
2
TL074
U2, U7
4
DG403
U3, U4, U5, U6
1
TL072
U8
4
2N3904
Q1, Q2, Q3, Q4
2
DMMT5401
Q5, Q6
1
Conn_01x04_Female
J1
4
Conn_01x04_Male
J2, J8, J13, J14
1
B_IN
J3
1
A_IN
J4
1
B_OUT
J5
1
A_OUT
J6
1
EURORACK_CONN_16
J7
2
Conn_01x08_Female
J9, J11
2
Conn_01x08_Male
J10, J12
1
R_ATTACK
RV1
1
R_DECAY
RV2
1
R_SUSTAIN
RV3
1
R_RELEASE
RV4
4
D
D1, D2, D3, D4
Show 8 more
QtyPartRefs
8
0.1u
C1, C3, C5, C6, C7, C8, C9, C10
2
100n
C2, C4
2
4.7u
C11, C12
4
6.8k
R1, R7, R19, R20
6
1K
R2, R6, R8, R12, R21, R23
8
100K
R3, R4, R5, R9, R10, R11, R22, R24
2
1M
R13, R14
4
10K
R15, R16, R17, R18

Adsr design files

The KiCad project lives in the rabidaudio/synthesizer repository on GitHub; these links point at the commit this page was built from.

Adsr: common questions

How big is the Adsr PCB?

The Adsr measures 29.5 × 112.3 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Adsr?

72 components, from 28 distinct parts. The full bill of materials is listed on this page.

Where can I download the Adsr design files?

From the rabidaudio/synthesizer repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the Adsr design in my own project?

Yes, under the terms of its MIT license, which rabidaudio chose for the repository.

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