[Kenny12]

Hi, i'm thinking of using a external switch on the pi meta, basically one that switches between DC Jack, Battery, and Off

which jacks and switches should i use, and how should i go about wireing it?

 

[till]

You need a three-position, three-pole switch. Wiring should be according to the datasheet of the switch, or you figure it out with a multimeter. I have a switch that works like this:
I - 0 - II
It has three poles, and switched to I, it connects the left and the middle pole. On II, it connects the right pole and the middle pole; on 0, all poles are disconnected. So, in this case, you could solder the plus of the battery to the left pole, the plus of the DC jack to the right pole, and the amp circuit to the middle pole. So on I, the amp will work on battery, on 0, it is off, and on II, the DC jack is connected.
HTH

EDIT: I was talking nonsense at first, so I had to edit the text

 

[stereth]

You could use an SPDT On-Off-On toggle switch as well. It has three positions; up and down connect two lugs like they should, and it has another position in the middle that disconnects both. If you're worried about bumping it, you could spend a little more for a locking switch.

 

[Kenny12]

so it wouldn't matter if the + on the batt and the +/- on the DC input are jumpered?

 

[taylor]

You need a DPDT switch.

It is pretty much two SPDT switches in one box.

The way it works is that for each SPDT switch there are 3 connectors. Two are inputs, and 1 is output. The switch is selectable from shorting Input A > Output or Input B > Output. Most also have a position where neither of the inputs are connected. What you need to do is connect the + terminal ont he pimeta to the output terminal on the DPDT switch. Then, on 1 of the inputs, connect the + of the DC barrel jack, and to the other input connect the + of the battery. Repeat the same for the - terminals on the other part of the switch. In general, the output connectors are in the middle and the input connectors are on the ends. Time fo ACSII art!

Code:

[left] DPDT Switch V - on battery -------| |---------------- + on battery - on Pimeta --------| |---------------- + on Pimeta - on jack ----------| |---------------- + on jack[/left]

 

[tangent]

My question to you, Kenny, is "why?" The way I'd do it is to have a regular power switch and use a closed-circuit DC input jack. The battery current runs through the jack to the amp when there's nothing plugged into the jack, and the amp runs from the wall when you plug something in that way.

Regarding the other suggestions, the SPDT on-off-on one is the only one that will work. I don't think you'll find a 3P3T switch, and if you did it would be either very big or very expensive. And the DPDT idea doesn't work at all if you use a standard on-on type: there is no off position. You could use a DPDT on-off-on switch, but the only difference between that and stereth's SPDT idea is that you're switching both legs of the power, which is nice but not essential.

 

[Kenny12]

tangent i thought u said that closed dc inputs are easy to break on your site?