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Output mixer

mohoyt·output_mixer

Output mixer PCB layout, top view — open source board by mohoyt

About the Output mixer PCB

Output mixer is an open source PCB design by mohoyt, published on GitHub under the CERN-OHL-S-2.0 license. It is a 2-layer board measuring 40 × 99 mm, with 114 components from 33 distinct parts.

Other key parts include the TL072. By type, the board carries 56 resistors, 18 diodes, 16 capacitors, 10 test points, 6 connectors and 4 transistors.

It belongs with the audio designs in this gallery.

From the project

Simple 4 channel Eurorack output mixer

Inspired by the mixer in the Erica Synths x mki.edu line (but with added channels and SMD components)

All addressed in current version (v1.1). The overheating was a result of poor quality BD139 and BD140 that I had sourced.

Output mixer, from the project README
From the project README

Main components on the Output mixer

TL072

Output mixer bill of materials (BOM)

114 components, 33 distinct parts.

QtyPartRefs
3
TL072
U1, U2, U3
2
BD139
Q2, Q4
2
BD140
Q3, Q5
2
IN1
J1, J3
2
IN2
J2, J4
1
Headphones
J5
1
Line out
J6
1
Conn_01x10
CONN1
1
A
TP1
1
B
TP2
1
C
TP3
1
D
TP4
4
GND
TP5, TP6, TP7, TP8
1
E
TP9
1
F
TP10
16
1N4148
D1, D2, D3, D4, D5, D6, D7, D8 +8
2
1N5819
D17, D18
4
1uF
C1, C14, C15, C23
2
47uFx16V
C2, C3
8
0.1uF
C4, C5, C6, C7, C8, C9, C12, C13
Show 13 more
QtyPartRefs
2
22pF
C16, C17
2
10
R1, R2
8
1k
R3, R4, R28, R29, R32, R39, R40, R58
4
B100k
R5, R6, R41, R44
12
100k
R7, R8, R22, R31, R42, R45, R50, R51 +4
4
200k
R12, R13, R43, R46
8
10k
R14, R15, R16, R17, R21, R27, R47, R48
2
30k
R18, R33
4
3.6k
R19, R20, R34, R35
4
B10k
R23, R49, R52, R53
4
2R0
R24, R25, R36, R37
2
47R 1W
R26, R38
2
470
R30, R59

Output mixer design files

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

Output mixer: common questions

How big is the Output mixer PCB?

The Output mixer measures 40 × 99 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Output mixer?

114 components, from 33 distinct parts. The full bill of materials is listed on this page.

Where can I download the Output mixer design files?

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

Can I use the Output mixer design in my own project?

Yes, under the terms of its CERN-OHL-S-2.0 license, which mohoyt chose for the repository.

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