A 12 input sum amplifier with balanced inputs and output.
Documents:
http://audioxxx.googlepages.com/SUM-12_schematic.pdf
http://audioxxx.googlepages.com/SUM-12_wiring.pdf
http://audioxxx.googlepages.com/SUM-12_layout_designations.pdf
http://audioxxx.googlepages.com/SUM-12_layout_values.pdf
http://audioxxx.googlepages.com/SUM-12_copper_mirror_image.pdf
Input connector (D-25 female) is placed on PCB so manual wiring between sum resistors and connector is not required.
The board is 70 x 50 mm single sided and designed so that it is suitable for home etching.
THD: 0.002%
Noise: -100 dBu (1 source connected), -90 dBu (12 sources connected)
Gain: 0 dB
Maximum level: +28 dBu
Unbalanced output: Leave R28 out and take output from the + output terminal.
**********
My other projects:
Studer 169 EQ
http://www.groupdiy.com/index.php?topic=33996.0
Neumann W492 EQ
http://www.groupdiy.com/index.php?topic=28332.0
Neumann OA10 discrete op-amp
http://www.groupdiy.com/index.php?topic=34105.0
Balancing/unbalancing amplifier
http://www.groupdiy.com/index.php?topic=29333.0
Documents:
http://audioxxx.googlepages.com/SUM-12_schematic.pdf
http://audioxxx.googlepages.com/SUM-12_wiring.pdf
http://audioxxx.googlepages.com/SUM-12_layout_designations.pdf
http://audioxxx.googlepages.com/SUM-12_layout_values.pdf
http://audioxxx.googlepages.com/SUM-12_copper_mirror_image.pdf
Input connector (D-25 female) is placed on PCB so manual wiring between sum resistors and connector is not required.
The board is 70 x 50 mm single sided and designed so that it is suitable for home etching.
THD: 0.002%
Noise: -100 dBu (1 source connected), -90 dBu (12 sources connected)
Gain: 0 dB
Maximum level: +28 dBu
Unbalanced output: Leave R28 out and take output from the + output terminal.
**********
My other projects:
Studer 169 EQ
http://www.groupdiy.com/index.php?topic=33996.0
Neumann W492 EQ
http://www.groupdiy.com/index.php?topic=28332.0
Neumann OA10 discrete op-amp
http://www.groupdiy.com/index.php?topic=34105.0
Balancing/unbalancing amplifier
http://www.groupdiy.com/index.php?topic=29333.0