Need an input selector and/or volume controller for my amp - Google ain't much help!!

[johnalexwarren]

Evening all!

Well I've spent the last couple of hours Googling to try and find a 3 or 4 source input selector (well at least 2 source, possibly with integrated volume control) for my amp but so far it's been pretty fruitless.

Can anybody help? Ideally I need one with a PCB layout/component list and I don't need tone or balance controls.

Thanks!

John.

[Tekko]

look on ebay, there are remote controlled input selector and volume control kits out there.

[johnalexwarren]

There certainly are but at £40 that's almost as much as the amp cost me to make! Maybe the manufacturer will send me a schematic lol!

[theAnonymous1]

It can be as simple as a 3 or 4 position 3-pole rotary switch for the selector and a potentiometer for the volume control. You didn't specify whether you need it to be remote controlled or not though.

[johnalexwarren]

Well those were actually my initial thoughts and I have a dual gang pot for the volume control, however I've read a number of articles and it seems that the general concensus is that rotary switches can introduce noise to the circuits...? I don't need remote controlled but I wouldn't object to it! The simpler/cheaper the better!

[dmx2020]

May be this one: 5 way switch

[theAnonymous1]

Originally Posted by johnalexwarren

Well those were actually my initial thoughts and I have a dual gang pot for the volume control, however I've read a number of articles and it seems that the general concensus is that rotary switches can introduce noise to the circuits...?

I don't see why a properly wired selector switch would add any noise; it never has for me anyway.

[johnalexwarren]

Well there's nothing like trial and error so I guess the thing to do it give the rotary a try and see what happens. Cheers guys!

[johnalexwarren]

Been pondering my options over a bottle of Fursty Ferret and it occurred to me that maybe I'm just making things more complicated than they need to be. Would really appreciate your opinions on the below...

My amp will primarily be used for a CD player with the occasional bout of vinyl indulgence, and there's not going to be a lot of source switching, so is it not a viable option to take the switch out of the signal path altogether and wire two inputs into one?

Will there be any detrimental effect to the signal/amp this way, and is it simply a case of connecting both inputs (one via a pickup pre-amp) to the PCB connectors or is there more two it? What would happen if two signals were accidentally played at the same time?

Thanks,

J.

[dave_gerecke]

Hello johnalexwarren, it's not a good idea to connect two different outputs from different devices to the same input. You could potentially blow up the output of both devices. I would recommend that you use at least a two way switch for your inputs, if you have switching. You could get away with a common DPDT switch here, as the ground wires should be common, thus don't need switching. If you desire more inputs, you could also try using an old printer switch from a computer. There are ones out there that had 4 positions. They usually have a lot of decks, more than necessary, but you can ignore them.
And last but not least, if you aren't going to be switching inputs often, you could always just build the amp with one input, and then swap the cables from the source as necessary. If you do this, remember to turn the amp off first.

Peace,

Dave