Tapping into the Amp without 3.5 Aux

Hi Everyone! I have a few of these laying around

and a few of these as well
http://mcartorlaw.com/Plug-3-watt-Speakers-2Pcs-4-ohm-Degraw-DIY-Speaker-Kit-320254/

I tried to probe the Aux jack on this board to find what wires to soilder but I am uncertain if I am to expect a DC voltage out from any of the 5 solider points on the board. Judging from the looks only two of the pins are used I assume Tip and Ring and the others are just for joining it to the board itself.
There’s a video here showing a guy doing the same thing but I am unsure if a direct connection to my speakers would work. Does anyone know what chip they are using on this board? I can’t seem to find the datasheet for it anywhere.

Thank you!!

I tried to probe the Aux jack on this board to find what wires to soilder but I am uncertain if I am to expect a DC voltage out from any of the 5 solider points on the board. Judging from the looks only two of the pins are used I assume Tip and Ring and the others are just for joining it to the board itself.

Sometimes those pins are ground and sometimes they are just for mounting.

The easiest way to check is to plug-in a cable and "ohm it out" from the other end of the cable.

There's a video here showing a guy doing the same thing but I am unsure if a direct connection to my speakers would work.

Without any specs it's hard to know but a direct connection to the 4 or 8 Ohm speakers probably won't work. Line outputs are nominally 10K Ohms and they'll often work down to 1K but a few Ohms is really "pushing it". A headphone-output* is usually good down to around 30 Ohms.

http://mcartorlaw.com/Plug-3-watt-Speakers-2Pcs-4-ohm-Degraw-DIY-Speaker-Kit-320254/

Have you tried those speakers with your computer?
Have you tried them with the normal cable connection before you start "hacking"?

  • The voltage out of headphone jack is about line level, and there's always a volume control on a headphone-out so you can adjust it. It's perfectly OK to plug headphone-out to line-in. For example, you can plug powered computer speakers (line level) with a 10K input impedance into the headphone jack on your phone or laptop.