Small Signal Relays - Alternatives
The RedRoo amplifier uses two signal-relays to switch between the two RCA inputs and the Bluetooth input. This avoids having to hand wire a conventional input selector switch, and terminate a lot of hand wired shielded cable.
Compared to larger power relays, signal relays offer superior contact reliability with a small signals, due to the structure of the relay and the switching contact material.
The relay specified is: KEMET EC2-12NU The Digikey part number is 399-11029-5-ND
We chose the particular small signal relay mainly because the pin footprint does not allow it it to be soldered-in backwards.
A slightly more expensive alternative is : TE Connectivity V23079A1003B301 Digikey part PB289-ND