Tired of yanking cables to hook up different sound cards with your Taigen V3 board? If you can solder, then get a '4PDT' (four-pole, double-throw) switch from Amazon, ebay, or most electronics parts & surplus stores (mine cost a whopping $3 and locks in place to prevent accidental bumps). Preferably use an 'ON-ON' switch, but an 'ON-OFF-ON' will work albeit with the dead spot in the middle... the idea is to be able to manually switch the 4-pin control cable going from the board to either sound card, while the 3-pin volume and 2-pin speaker cables can just be spliced together in a 'Y' configuration (otherwise you'd have to flip 3 switches), since no harmful voltage will be fed back thru either inactive circuit. See following photo descriptions for more... I could've wired directly to avoid connectors, but I like to do things non-destructively! With "sub-switching" you could hook up more than two cards

4PDT switch by itself

Properly wired to the soundcards

Switch attached to small metal L-bracket behind motors

3-pin volume 'Y' cable

2=pin speaker 'Y' cable, with reverse 'Y' on other end to allow 2 speakers to be used; wired in series so the resistance / impedance (ohms) doesn't drop

Final assembly fully wired, waiting to go back in the tank