Hello,
Purchased a few of these boards. I have noticed all of the boards make a weird noise in the lower bass region. It is almost like the driver is rubbing but it is not. I have tried the amps on a few drivers and they all make the sound, but not with other amps. I have also tried 3 different power supplies and that has not solved the noise issue.
The few things I have noticed are the heat sink is really warm; much warmer than the other 3116s I have on hand and other class d amps I have. And the inductors get extremely hot.
Any ideas what could be happening? And can it be fixed?
Thanks!
Purchased a few of these boards. I have noticed all of the boards make a weird noise in the lower bass region. It is almost like the driver is rubbing but it is not. I have tried the amps on a few drivers and they all make the sound, but not with other amps. I have also tried 3 different power supplies and that has not solved the noise issue.
The few things I have noticed are the heat sink is really warm; much warmer than the other 3116s I have on hand and other class d amps I have. And the inductors get extremely hot.
Any ideas what could be happening? And can it be fixed?
Thanks!
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As explained by rayma, it could well be the inductors saturating.
I have also had chokes with so large core-losses that they became hot, but the manufacturer should have noticed that.
Another (theoretical) possibility is if the BTL coupling is made wrong. The two channels need to be fully synchronized to avoid shoot-through in the output switches.
Try to measure if you have a DC voltage across your speakers (without sound)?
What supply voltage do you use?
If possible, try with a 12V (or even 9V) supply. Still weird bass and choke heating?
I have also had chokes with so large core-losses that they became hot, but the manufacturer should have noticed that.
Another (theoretical) possibility is if the BTL coupling is made wrong. The two channels need to be fully synchronized to avoid shoot-through in the output switches.
Try to measure if you have a DC voltage across your speakers (without sound)?
What supply voltage do you use?
If possible, try with a 12V (or even 9V) supply. Still weird bass and choke heating?
I will measure the DC voltage later today and I will try a 12V supply as well. Thanks.
These ampboards used to be configured as slaves. Meaning they need a master to tell them at what switchingfrequency they should run. They do not have a master (clock) so they run at a state not in datasheet, not stable, but switching around 100kHz.
The noise and a lot of other issues have been mentioned by others, you basically have a non tpa3116 ampboard. To make it tpa3116 set chips to master, see datasheet, easiest to remove one resistor, but that will be 20dB gainsetting master, if you will be using phone or portable sources that amplificationfactor might not be enough.
The noise and a lot of other issues have been mentioned by others, you basically have a non tpa3116 ampboard. To make it tpa3116 set chips to master, see datasheet, easiest to remove one resistor, but that will be 20dB gainsetting master, if you will be using phone or portable sources that amplificationfactor might not be enough.
I think I found out what it might be: That's a BTL board with differential input. If you do not have a balanced input (i.e. XLR) but keep the board in that configuration the two bridged channels work against each other, one wants to keep the output at zero (because it does not get it's part of the signal), the other wants to play the signal. To fix this on this particular board, you need to connect the input - with the board gnd.
I can confirm that this is a differential board and expects two signals, one hot and one cold - that is why there are two 1uF input capacitors. I have four of them running successfully of a commercial 24V SMPS tuned down to 21V (the lowest it can be set to using the trimmer).
Since I did not have a balanced source I simply grounded one side of the input. The amps work fine, I use one to drive two 4 ohm subs connected in parallel and the other a 4 ohm line array, with an active crossover. It's given me no indications of being defective. I did replace the input power capacitor with something a little more sturdy for the bass amps. for the others I left the "Rubycon" ones in.
From what I remember they were not at all happy driving an 8 ohm load, and are happiest with low impedance loads. Yes the inductors and the sinks run very hot. I've decided that it will die when it has to. I'm hoping you paid very little for them, as that's all they're worth.
Since I did not have a balanced source I simply grounded one side of the input. The amps work fine, I use one to drive two 4 ohm subs connected in parallel and the other a 4 ohm line array, with an active crossover. It's given me no indications of being defective. I did replace the input power capacitor with something a little more sturdy for the bass amps. for the others I left the "Rubycon" ones in.
From what I remember they were not at all happy driving an 8 ohm load, and are happiest with low impedance loads. Yes the inductors and the sinks run very hot. I've decided that it will die when it has to. I'm hoping you paid very little for them, as that's all they're worth.
Yeah, I only paid a like $5 for them, so no big deal.
I am running the ground from my input to the ground pin on the board and leave the -ve pin floating.
And I only noticed this because my intention was to build a sub for my outdoor system. I have used one of these amps for a small bluetooth boombox running on mono and I did not hear anything on that set up because I used 3" full range drivers. So no real bass to speak of.
Thanks for all of the replies so far!
I am running the ground from my input to the ground pin on the board and leave the -ve pin floating.
And I only noticed this because my intention was to build a sub for my outdoor system. I have used one of these amps for a small bluetooth boombox running on mono and I did not hear anything on that set up because I used 3" full range drivers. So no real bass to speak of.
Thanks for all of the replies so far!
Just tried a 12V power supply. I think the noise is actually worse?? The inductors and chip do not run as hot as when I run 24V on them. Also, no DC on the output with no signal.
What does the jumper do? One pin is labelled GND and the other M. Is this the master/slave set up?
What does the jumper do? One pin is labelled GND and the other M. Is this the master/slave set up?
This is the board: 1X DC 12V-24V TPA3116 Mono Channel Digital Power Audio Amplifier Board BTL 100W` 6959011595545 | eBay
And there is a note in the item description:
Note: When unbalanced input, "-" must be shorted to GND, otherwise the sound is not normal, serious may burn the chip.
That not only fits the error description, it also gives the same solution. The TPA3116 actually is fully differential. But you forgot it also is a PBTL configuration and each of the inputs can still be driven individually, meaning they can have flipped input polarity or dual flipped polarity (input/output each for symmetry reasons, even if that would not make that much sense at this amplifier).
Thanks ICG. So just connect the GND and -ve together then? Sorry for my ignorance, but all of this is new to me.
And M stands for mute, haha, got it now.
And M stands for mute, haha, got it now.
Ok, connected the GND and -ve inputs on the amp together and then connected to earth and viola, no more noise when playing music. Single amp only right now. Thanks ICG!
Clean, deep bass. Pretty impressive actually for this little amp. And at 12V, still running cool.
I still have an audible hiss, ground loop perhaps? Much lower when connected to earth. But I can deal with that for now.
Thank you everyone for your input.
Clean, deep bass. Pretty impressive actually for this little amp. And at 12V, still running cool.
I still have an audible hiss, ground loop perhaps? Much lower when connected to earth. But I can deal with that for now.
Thank you everyone for your input.
If it's hiss (as opposed to lower-frequency hum), it may well be the "ubiquitous" issue with these amps being factory-configured for maximum gain.
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