I am in the process of designing and ordering components for my next project and am new to the whole audio thing. I plan on creating a mp3 player of sorts, with external speakers. I eventually will be making this wireless (using bluetooth)
If you look at the hookup guide above(sparkfun link) there is a section titled "Line Out Warning". From my understanding the '-' is gpuf and not a ground and thus a speaker that is hooked up needs to be grounded through a different method. Can I simply hook up the positive of my right speaker to the 'R', the left speaker positive to the 'L' and just put the grounds to a common ground?
Adafruit also sells 1watt 8ohm speakers that interface well with this amp. I'm not exactly sure how to hook this up to the mp3 shield. There is a R+,L+ and L-,R-, according to the link above I should be able to combine the L- and R- to a common ground. Naturally the R+,L+ would go the the respective pins on the mp3 shield. Do I need to worry about anything else? The "Line out" warning posted on the sparfun link has me a bit confused on exactly how to ground the connecting output (in this case the amp).
Thanks for all help and suggestions (again I'm new to audio)
First, you cannot connect a regular 8-Ohm speaker. It says you can connect headphones or Active (powered) speakers. That means something like computer speakers that have an amplifier built-in and plug-into wall power, or have "wall wart" power supply.
That ground note is unusual... Normally a line-output is ground referenced. I didn't read the application notes so I don't know about the solutions or work-arounds. With headphones, it's no problem to have the ground "floating", but with powered speakers or an amplifier, etc., you'd have to deal with that ground problem.
P.S.
OK, I looked at section 3.2 of the application note. The solution is to add a capacitor to each output (C1 & C2 shown on the application note) and then use a real ground. This means you cannot use the 3.5mm headphone jack (except with headphones) because it doesn't have a true ground. (You have to use "R" & "L", connections plus a ground pin.) You should be able to skip the other parts as long as you have the capacitors. 0.1uF capacitors should be fine.
DVDdoug:
First, you cannot connect a regular 8-Ohm speaker. It says you can connect headphones or Active (powered) speakers. That means something like computer speakers that have an amplifier built-in and plug-into wall power, or have "wall wart" power supply.
That ground note is unusual... Normally a line-output is ground referenced. I didn't read the application notes so I don't know about the solutions or work-arounds. With headphones, it's no problem to have the ground "floating", but with powered speakers or an amplifier, etc., you'd have to deal with that ground problem.
P.S.
OK, I looked at section 3.2 of the application note. The solution is to add a capacitor to each output (C1 & C2 shown on the application note) and then use a real ground. This means you cannot use the 3.5mm headphone jack because it doesn't have a true ground. (You have to use "R" & "L", connections plus a ground pin.) You should be able to skip the other parts as long as you have the capacitors. 0.1uF capacitors should be fine.
Thanks for the help/direction.
I updated the OP with a link to an amp. Could you give a bit of guidance on how to hook up the amp to the mp3 shield. The grounding issue has me a bit confused. Thanks!