Hello all,
I like to use some TPA3116 bluetooth amps (like this one here) for various portable speaker projects. Generally these projects are single mono setups. I've been just wiring them to right channel on the amp. Missing that left channel really makes a difference some times in how the music sounds so I was wondering what would happen if I wired to both channels in parallel? I don't expect to get any more power out of the amp I'd just like to sum the channels together. Would wiring the outputs together fry the amp or would it sum the outputs how I'd like?
Any input will be greatly appreciated!
I like to use some TPA3116 bluetooth amps (like this one here) for various portable speaker projects. Generally these projects are single mono setups. I've been just wiring them to right channel on the amp. Missing that left channel really makes a difference some times in how the music sounds so I was wondering what would happen if I wired to both channels in parallel? I don't expect to get any more power out of the amp I'd just like to sum the channels together. Would wiring the outputs together fry the amp or would it sum the outputs how I'd like?
Any input will be greatly appreciated!
Can you sum the input signals to mono before applying to the right channel of the amp, keeping the power amp configured to stereo since you don't need more power? That might do what you want without requiring any power amp changes, you can sum to mono with series resistors at the input of the power amp chip. I don't think you can sum the outputs together to get a mono output if the chip is connected in Stereo mode, but it might be worth asking a TI applications engineer. There are power components that you can connect in parallel (such as LM317 linear regulator ICs) if you put low value resistors in series with the outputs so the load can be shared. It's unlikely you can do this with the 3116, and I didn't see it in the 3116 data sheet, but it might be worth asking a TI engineer.
The 3116 does have a mono mode connection, but it is a bit unusual at least IME. You have to connect both left channel IC input pins to ground, that places it in mono mode. You then connect the right channel + and - together for the + out to your mono load, and the left channel + and - together for the - out to the load. Please see the TPA3116 data sheet for details.
Looking at the board a bit more, you should be able to gain access to the 3116 inputs, as its inputs have to be capacitively coupled to the bluetooth adapter (so the power amp chip starts up correctly in stereo mode). Just trace the circuit to those caps, remove the caps, and you can skywire the resistive stereo to mono adapter to the board fairly easily. Be sure and capacitively couple the summed circuit to the power amp input you want to use, and terminate the input of the other channel (ground the bluetooth side pad of the cap, and also isolate that cap pin from the bluetooth output).
The 3116 does have a mono mode connection, but it is a bit unusual at least IME. You have to connect both left channel IC input pins to ground, that places it in mono mode. You then connect the right channel + and - together for the + out to your mono load, and the left channel + and - together for the - out to the load. Please see the TPA3116 data sheet for details.
Looking at the board a bit more, you should be able to gain access to the 3116 inputs, as its inputs have to be capacitively coupled to the bluetooth adapter (so the power amp chip starts up correctly in stereo mode). Just trace the circuit to those caps, remove the caps, and you can skywire the resistive stereo to mono adapter to the board fairly easily. Be sure and capacitively couple the summed circuit to the power amp input you want to use, and terminate the input of the other channel (ground the bluetooth side pad of the cap, and also isolate that cap pin from the bluetooth output).
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