TPA3116d2 problem.
40W RMS loudspeaker, amplifier output voltage only 6V RMS, current consumption of the amplifier 0,4A, powered by a 24V 7ah battery. 24V * 0,4A = 9,6W. When powered by a 12V battery, the current consumption of the amplifier is very similar. Where to look for the problem ?
40W RMS loudspeaker, amplifier output voltage only 6V RMS, current consumption of the amplifier 0,4A, powered by a 24V 7ah battery. 24V * 0,4A = 9,6W. When powered by a 12V battery, the current consumption of the amplifier is very similar. Where to look for the problem ?
How are you measuring the 6V RMS? Is that one phase to ground
(incorrect) or the differential between the +/- outputs? Do you
know what the gain is supposed to be? Did it change after a while?
G²
(incorrect) or the differential between the +/- outputs? Do you
know what the gain is supposed to be? Did it change after a while?
G²
AC measurement, taken with a TrueRMS meter, difference between + and -. I have seen that for a 4Om speaker it should be 15V. I have 5-6V maximum at all times.
The audio input signal is given by the telephon. I measure the output with a multimeter while playing audio, I don't have an oscilloscope. The speaker plays much quieter with the TPA3116d2 than with the car radio, where the power is 17-19 W per channel.
have a look at my posting here:
https://www.diyaudio.com/community/threads/tpa3116d2-and-ne5532-pre-amp.367509/post-6526380
this amp is not very well built, unfortunately.
coils are not up to the task and heat up.
idle current is high.
The opamps are fake 5532s (I measured them here: https://www.diyaudio.com/community/threads/fake-op-amp-or-not.393883/post-7533474)
sorry for bad news.
Yeah, but the multimeters can measure true RMS only up to a certain frequency.... after which the measurements are not accurate no more.
True RMS meer is digital? What frequency?
In short, if you are measuring music with a digital meter, you won't see anything which indicates the voltage across the speaker. The frequency is not right, and the meter is too slow.
A little bit more useful measurement would be a 60 Hz sine output onto a 4 ohm speaker. The frequency is right, and the signal is continuous.
Better measurement would be measuring a constant 400 Hz signal with an analog meter.
Best measurement is with an oscilloscope. If you don't have a scope you really cannot see WHY the output voltage is limited. Does it clip? Is the input signal insufficient?
Gain of BTL configuration is 36dB, which is about 60x. You can calculate the input voltage needed for a certain output voltage (and power).
Note that the stereo outputs are specified for 4 ohms. The bass channel uses two output stages in BTL parallen and could drive 2 ohms.
I am using this amplifier as well, and it produces an adequate sound level but nothing special. But what would you expect?
As far as I know they follow closely the application note on this datasheet: https://www.ti.com/lit/ds/symlink/tpa3116d2.pdf
Figure 37.
In short, if you are measuring music with a digital meter, you won't see anything which indicates the voltage across the speaker. The frequency is not right, and the meter is too slow.
A little bit more useful measurement would be a 60 Hz sine output onto a 4 ohm speaker. The frequency is right, and the signal is continuous.
Better measurement would be measuring a constant 400 Hz signal with an analog meter.
Best measurement is with an oscilloscope. If you don't have a scope you really cannot see WHY the output voltage is limited. Does it clip? Is the input signal insufficient?
Gain of BTL configuration is 36dB, which is about 60x. You can calculate the input voltage needed for a certain output voltage (and power).
Note that the stereo outputs are specified for 4 ohms. The bass channel uses two output stages in BTL parallen and could drive 2 ohms.
I am using this amplifier as well, and it produces an adequate sound level but nothing special. But what would you expect?
As far as I know they follow closely the application note on this datasheet: https://www.ti.com/lit/ds/symlink/tpa3116d2.pdf
Figure 37.
Well, usually, the meter isn't too slow, it's the display what's too slow. The internals of the digital meter usually update at several hundreds of Hz if not a few kHz. Of course, that doesn't change the outcome and lack of display capabilities/readabilities.
That depends on the circuit of the analog meter. There are analog ones which can display accurate values up to 10 or even 20k, others limit the frequency by the circuit to rectify the signal. You have to evaluate the meter to be sure to have a precise measurement. For the input signal, 400 Hz will be plenty to asess the issue though. I did not want to scholar you, I am aware you extremely likely know all that, I just wanted to prevent false assumptions on measurements.
If you have a scope, don't put it on AC, you DO want to see any DC offset, that's a major logic flaw "I want to measure AC". Again, that's not against you, that's for explaining to use the scope.
..and you won't have any more power unless you are using such a low impedance. Which means in the most cases, a PBTL is useless since you won't get any power increase.