source switch for amp

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You can put a small signal relay near the input section to switch between the two inputs and operate the relay by a rotary switch or a push button by simply energizing/de-energizing the relay coil. Switching grounds is not always necessary but can be done with the help of a second relay.

Regards,
Oleg
 
Oleg's solution is way too complicated for 2 sources. You need a power supply to drive the relay not connected to your analog power supply, a coil parallel diode, and you still need a switch unless you programmed a microcomputer. Two relays is not necessary when they sell DPDT and 4PDT relays.
You could use a DPDT toggle switch. They mount through holes in the panel so a drill motor and drill set are all that is required. Use safety glasses with power tools.

This is a DPDT solder terminal toggle switch with no center off. With the two poles, you can switch the returns also. https://www.newark.com/alcoswitch-te-connectivity/a201kzq04/switch-toggle-dpdt-5a-250v/dp/14M9102 It is better to use one with gold contacts for line level signals, but newark is not showing contact material today. The name of newark in other countries is farnell.com. Other distributors sell switches. Beware of switches rated for 20 A and up loads, that will be copper contacts.

If you want to avoid the freight charge, buy one from an auto supply. It will be copper contacts but will probably work for awhile. I don't know if your country is like Germany where auto parts come only from the Porche dealer or the VW dealer, but here in the US we have generic parts stores available. Route the wires well away from any AC driven power transformer or power switch. On line level devices I usually use an external transformer to prevent hum problems.
 
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Relay solution does not require an extra power supply. Just use one of the supply rails of your amplifier. For example Omron G6K series signal relay consumes only 4.6 mA when operating from 24VDC and I can hardly imaging how such a low current draw can disturb power rail of a well constructed amplifier. Just hook up a push button between the relay coil and the supply rail and use a voltage dropping series resistor if rail voltage is too high. What you get as a bonus is free choice of the push button position and shortest possible signal path.
 
Hi everybody and thank you for your replies. I think that I will go with a rotary type, it may not be necessary straight away as I planned on one RCA pair for DAC and a 3.5mm socket for smartphone wielding youngsters, but a rotary with enough stops allows me to add more sources if needed. Thanks.
 
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