How to add source selector to GC

[maurycy]

Few years ago I have built LM3875 based GC. Now, I want to put it in a nice case so it can finally make its way to the entertainment center under TV :-)

One modification I would like to do (if it is relatively easy), is to add source selector. Now, since my electronics knowledge is very limited, could somebody point me to schematics or instructions on how to wire source selector?

Also, where to get rotary switch that will server this purpose?

Thanks.

[ratza]

Input selector is just a double pole switch, find one having enough positions to fit your needs. The connections are very simple: the cursor goes to amplifier, all the other pins go to inputs (RCA plugs probably). All the grounds go toghether at signal ground.

[Praudio]

Originally Posted by maurycy

Few years ago I have built LM3875 based GC. Now, I want to put it in a nice case so it can finally make its way to the entertainment center under TV :-)

One modification I would like to do (if it is relatively easy), is to add source selector. Now, since my electronics knowledge is very limited, could somebody point me to schematics or instructions on how to wire source selector?

Also, where to get rotary switch that will server this purpose?

Thanks.

If 3 in. is enough for your need; go with 2 miniature DPDT switch.

[maurycy]

Thanks for replies. My case is setup for two pots. One would be volume and one source selector. Would something like that work?

4 Pole 3 Position Rotary Switch

[ratza]

Yes, it will work, you can even lift the ground for each RCA. Be careful, as it has three positions, therefore only three inputs can be used.

[maurycy]

So if I have set of three input RCAs (total of 6 single RCAs), that switch would work, right? I am kinda lost what the whole 4 pole means. I guess I have to do some reading.

[ratza]

Yes, it fits. 4 poles means that you have 4 different cursors, i.e. 4 signal lines.

[audio1st]

Originally Posted by maurycy

could somebody point me to schematics or instructions on how to wire source selector?

Hope it helps?

[maurycy]

Thanks a lot audio1st. Picture is worth 1000 words. I have printed it and now need to buy the switch. Once I have it, the connections should be pretty easy having this diagram.

[leadbelly]

Originally Posted by audio1st

Hope it helps?

That's a terrible way to do it. If you have extra poles on the switch, use them to switch the GROUND connection as well. This way can break ground loops and be noticeably quieter.