no no.
this is just 24db high pass filter.
it keeps my speakers away from reaching their xmax too early.
the first stage is a mono summer.
the tpa3123 is used for boombox-outdoor-purposes in this case, where i only use one single 8 ohm speaker.
it doesn´t work as great as i thought in the beginning.
i had the boombox under my desk.
i could drive it at volumes my neighbours and even myself got very uncomfortable.
but when i turn the volume pot a bit closer towards max, i hear only strange noises.
might that be clipping?
is the gain of two i built into the summer stage too much?
this is just 24db high pass filter.
it keeps my speakers away from reaching their xmax too early.
the first stage is a mono summer.
the tpa3123 is used for boombox-outdoor-purposes in this case, where i only use one single 8 ohm speaker.
it doesn´t work as great as i thought in the beginning.
i had the boombox under my desk.
i could drive it at volumes my neighbours and even myself got very uncomfortable.
but when i turn the volume pot a bit closer towards max, i hear only strange noises.
might that be clipping?
is the gain of two i built into the summer stage too much?
It might be clipping. I take it you are running off a 20 volt power supply. It looks like you have the pre-amp centered around 10 volts (Vref).
The minimum gain on the TPA3116 is 20 db which is a voltage gain of 10. So if the signal coming off the pre-amp is swinging 2 volts, the power amp output should be swinging 20 volts (hitting your rails). Another thought is the maximum input voltage rating for the TPA3116 is 6.3 volts. When you power up, the pre-amp output might send a 10 volt pulse to the inputs as it swings from ground to the mid-point of 10 volts.
I'm not an expert, and I hope someone will correct me if I am wrong, but I'd set Vref to something like 3 volts and drop the pre-amp gain to 1.
The minimum gain on the TPA3116 is 20 db which is a voltage gain of 10. So if the signal coming off the pre-amp is swinging 2 volts, the power amp output should be swinging 20 volts (hitting your rails). Another thought is the maximum input voltage rating for the TPA3116 is 6.3 volts. When you power up, the pre-amp output might send a 10 volt pulse to the inputs as it swings from ground to the mid-point of 10 volts.
I'm not an expert, and I hope someone will correct me if I am wrong, but I'd set Vref to something like 3 volts and drop the pre-amp gain to 1.
thanks for your reply.
the 20v source represents three 6v sla batteries.
the preamp and the 3123 are meant to be powered from that same source.
i will change the gain of the preamp to 1.
i don´t see how i can achieve the drop of Vref.
btw i think you mistook the 3123 for 3116.
info for all who googled this thread:
after a few months of testing i must say that a tpa3123 is not worth the trouble that brings the bridging with it.
i can say that at least for the red board from yuan jing.
i have done no modifications to the board.
this might make it a better.
tpa3116 and especially the black yuan jing board is very easy to mod to pbtl.
with a few modification this tpa3116 board has become my choice for a low cost mono board.
after a few months of testing i must say that a tpa3123 is not worth the trouble that brings the bridging with it.
i can say that at least for the red board from yuan jing.
i have done no modifications to the board.
this might make it a better.
tpa3116 and especially the black yuan jing board is very easy to mod to pbtl.
with a few modification this tpa3116 board has become my choice for a low cost mono board.
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