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A friend of mine has an old 5.1 audio system. The amplifier of the system has 5 cables as inputs to be connected to the audio source. My friend actually uses some cable splitters to send the stereo channel to each one of the 5 channels (yes, it's crazy, but please read on). He asked me if I can design and develop a PCB to avoid all that cables.

His idea was a PCB with 1 3.5mm jack "in" and 5 3.5mm jack "out":

Audio source ---- SPLITTER PCB --┳-- AMPLI IN 1
(PC/MP3/..)                      |-- AMPLI IN 2
                                 ...

Are there any impedance-related issues with a so simple design?

Enric Blanco
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Noisemaker
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    How are you going to feed the sub? Left channel only? Right channel only? Something else? Anyway, no there will probably not be any impedance issues as long as both units are of decent design. – Dampmaskin Apr 10 '17 at 15:46

1 Answers1

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All those audio inputs have quite a high input impedance (>5K and probably higher... my Denon AVR specifies it at 47K), so you shouldn't expect any loading problems even if you parallel all them together, because your audio source with have probably < 100 Ohm output impedance.

If you want to be on the safe side then add to your design a buffer between the audio source and the point where all the audio inputs are connected.

Enric Blanco
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