Good day guys...
This is my first time posting here, I'm from Philippines.
Please forgive me for lacking knowledge in amplifiers and electronic because I'm a newbie. I wanted to build a small amplifier that can delivery much power that is sufficient for my small speakers. From where I come from, they prefer louder and powerful Amplifiers that is not my type.
I choose to work with TDA8954 Board that is already available online, powered it with 27-0-27 VAC Toroidal Transformer...
Now begins my problem, after connecting the PSU and the Amp, it produce only 3-6vac on both channels left and right, while my TPA3116D2 produce 10vac powered with 24v Car Battery...
I have no idea what to check here, the TDA8954 Board has no signs of damage or what so ever.
Both TDA8954 and TPA3116D2 was tested using 4ohms speaker 150watts(PMPO)...
If you need more info regarding my trouble, feel free to ask because I don't know if I provided much enough...
Please give me inputs on what to check on this board, I would really appreciate it...
Thanks!
This is the sample picture of the Board :
This is my first time posting here, I'm from Philippines.
Please forgive me for lacking knowledge in amplifiers and electronic because I'm a newbie. I wanted to build a small amplifier that can delivery much power that is sufficient for my small speakers. From where I come from, they prefer louder and powerful Amplifiers that is not my type.
I choose to work with TDA8954 Board that is already available online, powered it with 27-0-27 VAC Toroidal Transformer...
Now begins my problem, after connecting the PSU and the Amp, it produce only 3-6vac on both channels left and right, while my TPA3116D2 produce 10vac powered with 24v Car Battery...
I have no idea what to check here, the TDA8954 Board has no signs of damage or what so ever.
Both TDA8954 and TPA3116D2 was tested using 4ohms speaker 150watts(PMPO)...
If you need more info regarding my trouble, feel free to ask because I don't know if I provided much enough...
Please give me inputs on what to check on this board, I would really appreciate it...
Thanks!
This is the sample picture of the Board :
An externally hosted image should be here but it was not working when we last tested it.
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If you have a correct supply voltage, the amplifier works well (trivial) and you have connected the wires right, you get more output than 3-6Vac only if the input signal amplitude times the gain allows more than 3-6Vac.
On the supply voltage: a 27-0-27 transformer delivers close to 2x29V unloaded and more than 40V rectified. Do you exceed the 42.5V maximum of the TDA8954 (please measure)?
For a start we assume the amplifier is fine (does it get unnaturally warm?) but the photo you posted does not load. Does the amplifier distort?
If the gain (amplification factor) of the TDA8954 is below that of your TDA3116D2, the output signal may be less simply because your input signal is not strong enough.
On the supply voltage: a 27-0-27 transformer delivers close to 2x29V unloaded and more than 40V rectified. Do you exceed the 42.5V maximum of the TDA8954 (please measure)?
For a start we assume the amplifier is fine (does it get unnaturally warm?) but the photo you posted does not load. Does the amplifier distort?
If the gain (amplification factor) of the TDA8954 is below that of your TDA3116D2, the output signal may be less simply because your input signal is not strong enough.
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Thank you for your response...
By the way, speaker sound would come out if I dial the potentiometer up to 4 - 5pm o clock (if you know what I mean), which is the supposed to be full max volume of the knob...
From zero (7pm on the clock) to around before 3/4 (4pm of the clock) of the knob, there is no sound coming out of the speaker, no reading on the output...
Sorry, I don't know how to upload picture, I'll try to upload later on my FB Account and link it here.
For the mean time, refer to below picture, thanks! :
AC16V~AC28VAC (recommended transformer 24v-0-24v) or -/+12 - -/+42DAC was the required PSU, I use a 27-0-27VAC, I measured it during test run and the voltage is stable on the input around 27.8vac each...
Where can I measure if I exceeded the 42.5VDC maximum?
Someone suggest that I should add a pre-amp to level the gain, but based on the forum, TDA8954 can be use without pre amp. How can I measure the gain, I already try to test if the potentiometer, I think it's working fine...
No distortion and it warms normal, around 30-35 Celsius, current temperature on my area is 38 degree Celsius, I will try to post it in my FB account later so I could link the picture here, the amp has no physical damage so I think there was just one bottle neck part that hinders the output to perform well...
In testing the amplifier board, I use the same equipment, Cellphone and Bluetooth received, as well as speakers...
My TPA3116D2 has built in pre amp, I think, because it has sa 2xNE5532 Chip if I'm not mistaken...
By the way, speaker sound would come out if I dial the potentiometer up to 4 - 5pm o clock (if you know what I mean), which is the supposed to be full max volume of the knob...
From zero (7pm on the clock) to around before 3/4 (4pm of the clock) of the knob, there is no sound coming out of the speaker, no reading on the output...
Sorry, I don't know how to upload picture, I'll try to upload later on my FB Account and link it here.
For the mean time, refer to below picture, thanks! :
An externally hosted image should be here but it was not working when we last tested it.
AC16V~AC28VAC (recommended transformer 24v-0-24v) or -/+12 - -/+42DAC was the required PSU, I use a 27-0-27VAC, I measured it during test run and the voltage is stable on the input around 27.8vac each...
Where can I measure if I exceeded the 42.5VDC maximum?
Someone suggest that I should add a pre-amp to level the gain, but based on the forum, TDA8954 can be use without pre amp. How can I measure the gain, I already try to test if the potentiometer, I think it's working fine...
No distortion and it warms normal, around 30-35 Celsius, current temperature on my area is 38 degree Celsius, I will try to post it in my FB account later so I could link the picture here, the amp has no physical damage so I think there was just one bottle neck part that hinders the output to perform well...
In testing the amplifier board, I use the same equipment, Cellphone and Bluetooth received, as well as speakers...
My TPA3116D2 has built in pre amp, I think, because it has sa 2xNE5532 Chip if I'm not mistaken...
Just to have a basic understanding of this board I found:
Ultra TDA8950 TDA8954 210W + 210W 2.0 after two channel Class D digital HIFI finished Power Amplifier board D4 001-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
Seems like a nice implementation and they recommend using until 2x28V AC.
There is a small red DIP-switch for the power supply. I cannot see what purpose it serves. Do you know?
I guess you use the green transformer supply connector to the left?
You can measure the rectified voltages on the two rows of large electrolytic capacitors. One row is likely to be for one power rail, the other for the other power rail. In order to measure, you have to turn the board around for a moment. Else, it may be possible to measure the rectified voltages on the blue connector (for DC voltages) next to the green connector you use for the transformer.
The TDA8954 gain is internally fixed at 30dB. A very common value. That should not prevent a good output. I have a different TDA8954 board and that one has no problem playing loud from a smart-phone headphone output.
A stupid question: have you set the other small red DIP-switch correctly? Non-BTL?
The potentiometer you talk about is the one on the amplifier? Potentiometers like that may have strange characteristics and for now turn it fully up (fully clockwise) and use the volume on your smart-phone. Like that the amplifier cannot play loud even with full volume from the phone?
Ultra TDA8950 TDA8954 210W + 210W 2.0 after two channel Class D digital HIFI finished Power Amplifier board D4 001-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
Seems like a nice implementation and they recommend using until 2x28V AC.
There is a small red DIP-switch for the power supply. I cannot see what purpose it serves. Do you know?
I guess you use the green transformer supply connector to the left?
You can measure the rectified voltages on the two rows of large electrolytic capacitors. One row is likely to be for one power rail, the other for the other power rail. In order to measure, you have to turn the board around for a moment. Else, it may be possible to measure the rectified voltages on the blue connector (for DC voltages) next to the green connector you use for the transformer.
The TDA8954 gain is internally fixed at 30dB. A very common value. That should not prevent a good output. I have a different TDA8954 board and that one has no problem playing loud from a smart-phone headphone output.
A stupid question: have you set the other small red DIP-switch correctly? Non-BTL?
The potentiometer you talk about is the one on the amplifier? Potentiometers like that may have strange characteristics and for now turn it fully up (fully clockwise) and use the volume on your smart-phone. Like that the amplifier cannot play loud even with full volume from the phone?
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` Sorry for the late reply, office work hinders me from getting back here at the forum but at last I was able to take actual pictures, sorry for the low quality though...
The Dip Switch let you choose what PSU you would use, 1 up, 2 down is for AC while 1 down, 2 up is for DC... It should be adjust when there is no power, because the unit will burn if there is power as I have read on the other seller. The 5pin chip beside it gets hot even there is no load, around 40 degree Celsius, I think its a regulator? On the other side, the blue box seems to have something moving from the inside when I shake it, I think it is not normal...
Yes, I have used the green connectors for AC, I was able to test it last night, it got stable voltage of 28-0-28 when there is no load, the blue connector for DC has a stable voltage reading of -/+37 when there is not laod. I test the capacitor using multimeter but I don't know how to use it, 5pcs straight, reads 4.9mF and other 5pcs straight line reads 4.8mF, I don't know if my process is right because out technician said that there are interference on capacitor when it is installed on the board so my reading would be far from accuracy...
May I know what board you used? Maybe I could order that one, instead of trying to figure out what's the problem with my current board. They say that maybe I have 26db gain and the board can't amplify it, how can I measure that?
Yes, I have tested the OCL and BTL selector on the dip switch on the front, sadly same output vac...
Here is the picture of the potentiometer that I'm talking about, sound only come out when the dial is near it's max full volume phase, if you look at the clock, when it's pointing on 4 and 5 o'clock, that when you can hear something, but turning it from before 4 o'clock all the way to 7 o'clock (counter clock wise), no sound produced. I tested this potentiometer, and there is resistance and seems to be working fine, I just don't know if it's correct potentiometer for these board. Both Full Volume on my Smart Phone and Amplifier Potentiometer produce around 6vac on the output. 2 smart phones already been used in this board, seems to have no hope for now...
thanks!
The Dip Switch let you choose what PSU you would use, 1 up, 2 down is for AC while 1 down, 2 up is for DC... It should be adjust when there is no power, because the unit will burn if there is power as I have read on the other seller. The 5pin chip beside it gets hot even there is no load, around 40 degree Celsius, I think its a regulator? On the other side, the blue box seems to have something moving from the inside when I shake it, I think it is not normal...
An externally hosted image should be here but it was not working when we last tested it.
Yes, I have used the green connectors for AC, I was able to test it last night, it got stable voltage of 28-0-28 when there is no load, the blue connector for DC has a stable voltage reading of -/+37 when there is not laod. I test the capacitor using multimeter but I don't know how to use it, 5pcs straight, reads 4.9mF and other 5pcs straight line reads 4.8mF, I don't know if my process is right because out technician said that there are interference on capacitor when it is installed on the board so my reading would be far from accuracy...
An externally hosted image should be here but it was not working when we last tested it.
May I know what board you used? Maybe I could order that one, instead of trying to figure out what's the problem with my current board. They say that maybe I have 26db gain and the board can't amplify it, how can I measure that?
Yes, I have tested the OCL and BTL selector on the dip switch on the front, sadly same output vac...
An externally hosted image should be here but it was not working when we last tested it.
Here is the picture of the potentiometer that I'm talking about, sound only come out when the dial is near it's max full volume phase, if you look at the clock, when it's pointing on 4 and 5 o'clock, that when you can hear something, but turning it from before 4 o'clock all the way to 7 o'clock (counter clock wise), no sound produced. I tested this potentiometer, and there is resistance and seems to be working fine, I just don't know if it's correct potentiometer for these board. Both Full Volume on my Smart Phone and Amplifier Potentiometer produce around 6vac on the output. 2 smart phones already been used in this board, seems to have no hope for now...
An externally hosted image should be here but it was not working when we last tested it.
thanks!
Thorough explanation, fine.
It is a well made board and it can be made to work. Far better than the board I bought and had to modify. I only mentioned my board to let you know TDA8954 boards generally work well with an ordinary SmartPhone. "Rome wasn't build in one day" as we say here in Europe - patience.
The blue thing next to the power select DIP-switch is a relay. The DIP-switch most likely controls the relay to choose one of the power inputs. The DIP-switch on its own would not have sufficient current rating. If you shake a relay strong enough it may make mechanical noise. Don't worry.
The small 5-pin IC is an SMPS and works with the small inductor marked "330". 40 degrees is fine.
2x37V is fine. Now we know the supply is right.
I will think a bit about your results and make a second posting.
Bye for now.....
It is a well made board and it can be made to work. Far better than the board I bought and had to modify. I only mentioned my board to let you know TDA8954 boards generally work well with an ordinary SmartPhone. "Rome wasn't build in one day" as we say here in Europe - patience.
The blue thing next to the power select DIP-switch is a relay. The DIP-switch most likely controls the relay to choose one of the power inputs. The DIP-switch on its own would not have sufficient current rating. If you shake a relay strong enough it may make mechanical noise. Don't worry.
The small 5-pin IC is an SMPS and works with the small inductor marked "330". 40 degrees is fine.
2x37V is fine. Now we know the supply is right.
I will think a bit about your results and make a second posting.
Bye for now.....
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The small SMPS power supply: I'm not sure exactly for what purpose it is used. Could you try to check the output voltage by measuring the voltage on each side of the small inductor marked “330”. On one side (probably facing the black LM2596 IC) the voltage you measure is not stable, but the other side (probably away from the LM2596) should give a stable DC voltage. Try what I believe to be the stable side first – if OK, forget the other. Knowing the stable voltage, I may guess the purpose.
As you mention, it may be very useful to measure the gain. Measuring the amplifier gain is quite trivial but requires a steady input signal. If you have a sine-wave generator, use that one. If not, download this 1KHz MP3-file from YouTube:
YouTube
Put it on one of your smart phones and play that for the test.
The test: Speakers on the outputs, the smart phone on the inputs and the dog out of the room. Eventually, ear protectors for yourself. Voltmeter in AC mode. Turn the board around for the test - then you have access to the soldering pads. Amplifier volume potentiometer turned fully up (clockwise). Identify a good ground pad to use as reference for the measurements (probably the mid-terminal of the green terminal block you use for transformer power). Adjust the volume on the phone to a loud, but not very loud, 1KHz sound in the speakers. Measure the ac signal amplitude at the input of the amplifier (output of the phone; both channels), at the output of the volume potentiometer (both channels) and at the amplifier output (on the speakers; both channels). With these values we can see if the amplifier has the 26/30dB gain.
OK?
As you mention, it may be very useful to measure the gain. Measuring the amplifier gain is quite trivial but requires a steady input signal. If you have a sine-wave generator, use that one. If not, download this 1KHz MP3-file from YouTube:
YouTube
Put it on one of your smart phones and play that for the test.
The test: Speakers on the outputs, the smart phone on the inputs and the dog out of the room. Eventually, ear protectors for yourself. Voltmeter in AC mode. Turn the board around for the test - then you have access to the soldering pads. Amplifier volume potentiometer turned fully up (clockwise). Identify a good ground pad to use as reference for the measurements (probably the mid-terminal of the green terminal block you use for transformer power). Adjust the volume on the phone to a loud, but not very loud, 1KHz sound in the speakers. Measure the ac signal amplitude at the input of the amplifier (output of the phone; both channels), at the output of the volume potentiometer (both channels) and at the amplifier output (on the speakers; both channels). With these values we can see if the amplifier has the 26/30dB gain.
OK?
Thank you for your response, I really I appreciate it...
I had to explain much because here in my place no one meddles with IC type boards, they like the transistor types here. So I'm used to it...
the IC with no load is around 34 degree celcius while the room temperature is 32...
I wasn't able to make a video, I'm a little bit busy on my day time work that it tolls my night time new hobby which is this amplifier, hehehe
Yah, I'm running out of patience with this board, it seems perfectly built but the lack of support from the vendor as well as local audiophiles here in my area hinders me to make it work. Thanks to you that gives me information and hope that I'll be able to use this board...
I thought that is a regulator, so that 5pin is a PSU also? I think I know what purpose it serves. After that 330, there are capacitors and 2pin, that pin is reguled 12vdc output for accessories like fan or MP3 Decoder...
An externally hosted image should be here but it was not working when we last tested it.
In my previous testing of the amplifier, I play the 50hz test tone that I used in settings gain on car amplifier, but in car amplifier you adjust the gain knob in accordance with vac output of the car amp, here there are no such gain knob or control.
Will download a test tone generator right now, or download from youtube.
I got a little bit confused; the black test lead will be at the center ground of the PSU, then the red test lead will measure VAC on the L/R Channel of Smart Phone and L/R Output of amplifier? How about Potentiometer Output, the ground will still be at the PSU Input common ground?
Thank you very much...
When you have to measure on an board which is compact and with small solder pads, it is important beforehand to decide where to touch with the measuring wires. If not, you risk measure something wrong or disturb the circuit you measure on (for instance an amplifier input).
When you measure AC with you voltmeter, you only need a potential that is stable with respect to the reference you like to use. A DC offset is no problem. In your case, we want to measure the signal (AC) amplitude. We do not know for sure if the potentiometer has a DC offset, but we don't care (AC measurement). Therefore, use the same ground as for the input measurement.
When you measure AC with you voltmeter, you only need a potential that is stable with respect to the reference you like to use. A DC offset is no problem. In your case, we want to measure the signal (AC) amplitude. We do not know for sure if the potentiometer has a DC offset, but we don't care (AC measurement). Therefore, use the same ground as for the input measurement.
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` Can't edit my reply in my previous post, waiting fo someone to reply but nothing commented so I would post my findings here, hopefully I will not get suspended for double posting...
I have tested the AC Voltage as you have suggested, 0.7 VAC on the Source and 4.7VAC on Each Output, left and right...
I don't know how to measure VAC of potentiometer yet. Only continuity and resistance...
I don't know if it's relevant or not, but I have read somewhere that if my transformer is made out of aluminum magnet wire, it will have an affect on sound quality, but the problem with that is it will have a voltage drop. My transformer didn't show signs of voltage drop but it is possible that it drops the ampere? I didn't try to test it yet, because it has 2 vac, how may I measure it? My tester has a limit of 10A...
Thanks...
I have tested the AC Voltage as you have suggested, 0.7 VAC on the Source and 4.7VAC on Each Output, left and right...
I don't know how to measure VAC of potentiometer yet. Only continuity and resistance...
I don't know if it's relevant or not, but I have read somewhere that if my transformer is made out of aluminum magnet wire, it will have an affect on sound quality, but the problem with that is it will have a voltage drop. My transformer didn't show signs of voltage drop but it is possible that it drops the ampere? I didn't try to test it yet, because it has 2 vac, how may I measure it? My tester has a limit of 10A...
Thanks...
Hi fidgety, good to hear from you again. You cannot edit a posting more than 30 minutes from when it is first put on the forum. After 30 minutes you will have to make another posting.
From your measurements of 4.7Vac on the output (speakers) with 0.7Vac on the input, I calculate only 16.5dB amplification (6.7 times) . That isn't much when they promise 30dB.
This is why I want to know the amplitude at the potentiometer. Unless you start removing the heatsink, we have to assume the signal level on the TDA8954 chip input to be close to the signal level at the output of the potentiometer.
Measuring the signal level at the output of the potentiometer is simple, I will explain: You put your multimeter in position "Vac" like you did to measure the input signal. When you measure the input signal level, you put the black measuring probe to signal ground and the red measuring probe to one of the input terminals (afterwards to the other input terminal to see if both channels are close to the same level).
Following the measurement of the input signal levels (on each input terminal), you leave the black measuring probe where it is on signal ground and you move only the red measuring probe! The red measuring probe you move to touch one of the middle terminals on the potentiometer.
Seen from the rear of the amplifier board, the potentiometer has 6 terminals arranged as two times 3 terminals. It is the two terminals in the middle of each line of three that interest us.
When you touch first one and then the other of the middle terminals on the potentiometer with the red measuring probe, you measure the signal level to the TDA8954 chip. That signal level should be close to the signal levels at the input but in this case it may not.
I want to see if the gain from the output of the potentiometer to the output of the amplifier (at the speakers) is 30dB.
From your measurements of 4.7Vac on the output (speakers) with 0.7Vac on the input, I calculate only 16.5dB amplification (6.7 times) . That isn't much when they promise 30dB.
This is why I want to know the amplitude at the potentiometer. Unless you start removing the heatsink, we have to assume the signal level on the TDA8954 chip input to be close to the signal level at the output of the potentiometer.
Measuring the signal level at the output of the potentiometer is simple, I will explain: You put your multimeter in position "Vac" like you did to measure the input signal. When you measure the input signal level, you put the black measuring probe to signal ground and the red measuring probe to one of the input terminals (afterwards to the other input terminal to see if both channels are close to the same level).
Following the measurement of the input signal levels (on each input terminal), you leave the black measuring probe where it is on signal ground and you move only the red measuring probe! The red measuring probe you move to touch one of the middle terminals on the potentiometer.
Seen from the rear of the amplifier board, the potentiometer has 6 terminals arranged as two times 3 terminals. It is the two terminals in the middle of each line of three that interest us.
When you touch first one and then the other of the middle terminals on the potentiometer with the red measuring probe, you measure the signal level to the TDA8954 chip. That signal level should be close to the signal levels at the input but in this case it may not.
I want to see if the gain from the output of the potentiometer to the output of the amplifier (at the speakers) is 30dB.
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` I was waiting for a reply, from the previous forum that I have joined, it is prohibited to bump a thread with double posting, so I was idle at a moment.
Glad to got a reply from you again, I really appreciate the help
I'm going to measure the things you say later and then report here what I found out... :3
The potentiometer mid when off was connected to the ground while when fully open is connected to the left and right, so this one's working right?
The left and right Channel gives 4.7vac playing full volume 1000hz at 0.7vac supply (I did the same on my TPA3116D2 and the gain is 1.1vac and the gain is near 7vac...).
I am kinda lost at the term amplitude, I don't know what it means yet, going to google it, hehehe
I was getting curious with the chip when you mention the heat sink, so I took it off and take a peak at the chip, it is TDA8954TH (NXP), so it seems legit ( I was having a doubt if I had the right chip...)
I have read here in the forum that there was case where the other amp board has low output then it turns out something about filter or resistor was not right in the board, replacing it produce better sounds, I'm thinking about maybe the same thing happen to this board?
Oh! I have discovered something, the output connection has wrong polarity on it, the L+ was actualy L-, fortunately my speaker didn't blow up when I connected BTL R+ and L-(L+ in real life)...
Here is pictuer under the board :
I forgot to mention that during my testing of 1k hz, the part of the heat sink that is touching the chip produce 51 degree Celsius...
Glad to got a reply from you again, I really appreciate the help
I'm going to measure the things you say later and then report here what I found out... :3
The potentiometer mid when off was connected to the ground while when fully open is connected to the left and right, so this one's working right?
An externally hosted image should be here but it was not working when we last tested it.
The left and right Channel gives 4.7vac playing full volume 1000hz at 0.7vac supply (I did the same on my TPA3116D2 and the gain is 1.1vac and the gain is near 7vac...).
I am kinda lost at the term amplitude, I don't know what it means yet, going to google it, hehehe
I was getting curious with the chip when you mention the heat sink, so I took it off and take a peak at the chip, it is TDA8954TH (NXP), so it seems legit ( I was having a doubt if I had the right chip...)
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I have read here in the forum that there was case where the other amp board has low output then it turns out something about filter or resistor was not right in the board, replacing it produce better sounds, I'm thinking about maybe the same thing happen to this board?
Oh! I have discovered something, the output connection has wrong polarity on it, the L+ was actualy L-, fortunately my speaker didn't blow up when I connected BTL R+ and L-(L+ in real life)...
An externally hosted image should be here but it was not working when we last tested it.
Here is pictuer under the board :
An externally hosted image should be here but it was not working when we last tested it.
I forgot to mention that during my testing of 1k hz, the part of the heat sink that is touching the chip produce 51 degree Celsius...
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Replies next to your questions:
The potentiometer mid when off was connected to the ground while when fully open is connected to the left and right, so this one's working right?
When fully open, the two mid terminals of the potentiometer are connected to the two potentiometer terminals to the right, the way your rear-side photo is taken.
The left and right Channel gives 4.7vac playing full volume 1000hz at 0.7vac supply (I did the same on my TPA3116D2 and the gain is 1.1vac and the gain is near 7vac...).
For the TDA8954: 0.7Vac input gives 4.7Vac output. Gain=4.7/0.7=6.7 times
For the TPA3116D2: 1.1Vac input gives 7Vac output; Gain 7/1.1=6.4 times.
Thus, it is not that the TDA8954 board has less gain than the TPA3116D2 board! Actually, the TDA8954 board has a little more gain than the TPA3116D2. The reason why you get more power out of the TPA3116D2 board is simply that you feed it with a higher signal. If you give the TDA8954 board 1.1Vac at the input it may also give 7Vac at the output.
I am kinda lost at the term amplitude, I don't know what it means yet, going to google it, hehehe
Amplitude means the size (value) of the signal. For DC values we talk about "voltage" or "tension", for AC signals we use "amplitude". The values you measured (0.7Vac, 1.1Vac, 4.7Vac and 7Vac are "amplitudes".
I was getting curious with the chip when you mention the heat sink, so I took it off and take a peak at the chip, it is TDA8954TH (NXP), so it seems legit ( I was having a doubt if I had the right chip...)
I believe it is "genuine" and even if it isn't, it is hardly the problem we look for.
I have read here in the forum that there was case where the other amp board has low output then it turns out something about filter or resistor was not right in the board, replacing it produce better sounds, I'm thinking about maybe the same thing happen to this board?
I have seen wrong component values used in amplifier boards. For the SMD boards with small SMD components, it is possible to read the values of most resistors but not capacitors. So, checking the values is difficult and for a start we have to assume the values are correct as in the datasheet.
Oh! I have discovered something, the output connection has wrong polarity on it, the L+ was actualy L-, fortunately my speaker didn't blow up when I connected BTL R+ and L-(L+ in real life)...
If you swap the L+ and L- it does not harm the amplifier but you get a wrong stereo perspective. If you by mistake connect a speaker from R+ to L+ you may damage the amplifier. Be careful with your connections.
I forgot to mention that during my testing of 1k hz, the part of the heat sink that is touching the chip produce 51 degree Celsius....
51 degrees Celsius is a bit high but not a problem for now. My TDA8954 board got to about the same level before I improved the cooling.
When you put back the heatsink, do not forget the insulating pad and thermal paste on both sides!
Conclusion: It seems the TDA8954 has the same gain as the TPA3116D2 board and the difference in output levels (4.7Vac/7Vac) is due to different input levels (0.7Vac/1.1Vac).
The potentiometer mid when off was connected to the ground while when fully open is connected to the left and right, so this one's working right?
When fully open, the two mid terminals of the potentiometer are connected to the two potentiometer terminals to the right, the way your rear-side photo is taken.
The left and right Channel gives 4.7vac playing full volume 1000hz at 0.7vac supply (I did the same on my TPA3116D2 and the gain is 1.1vac and the gain is near 7vac...).
For the TDA8954: 0.7Vac input gives 4.7Vac output. Gain=4.7/0.7=6.7 times
For the TPA3116D2: 1.1Vac input gives 7Vac output; Gain 7/1.1=6.4 times.
Thus, it is not that the TDA8954 board has less gain than the TPA3116D2 board! Actually, the TDA8954 board has a little more gain than the TPA3116D2. The reason why you get more power out of the TPA3116D2 board is simply that you feed it with a higher signal. If you give the TDA8954 board 1.1Vac at the input it may also give 7Vac at the output.
I am kinda lost at the term amplitude, I don't know what it means yet, going to google it, hehehe
Amplitude means the size (value) of the signal. For DC values we talk about "voltage" or "tension", for AC signals we use "amplitude". The values you measured (0.7Vac, 1.1Vac, 4.7Vac and 7Vac are "amplitudes".
I was getting curious with the chip when you mention the heat sink, so I took it off and take a peak at the chip, it is TDA8954TH (NXP), so it seems legit ( I was having a doubt if I had the right chip...)
I believe it is "genuine" and even if it isn't, it is hardly the problem we look for.
I have read here in the forum that there was case where the other amp board has low output then it turns out something about filter or resistor was not right in the board, replacing it produce better sounds, I'm thinking about maybe the same thing happen to this board?
I have seen wrong component values used in amplifier boards. For the SMD boards with small SMD components, it is possible to read the values of most resistors but not capacitors. So, checking the values is difficult and for a start we have to assume the values are correct as in the datasheet.
Oh! I have discovered something, the output connection has wrong polarity on it, the L+ was actualy L-, fortunately my speaker didn't blow up when I connected BTL R+ and L-(L+ in real life)...
If you swap the L+ and L- it does not harm the amplifier but you get a wrong stereo perspective. If you by mistake connect a speaker from R+ to L+ you may damage the amplifier. Be careful with your connections.
I forgot to mention that during my testing of 1k hz, the part of the heat sink that is touching the chip produce 51 degree Celsius....
51 degrees Celsius is a bit high but not a problem for now. My TDA8954 board got to about the same level before I improved the cooling.
When you put back the heatsink, do not forget the insulating pad and thermal paste on both sides!
Conclusion: It seems the TDA8954 has the same gain as the TPA3116D2 board and the difference in output levels (4.7Vac/7Vac) is due to different input levels (0.7Vac/1.1Vac).
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` I haven't got the time to measure yet the potentiometer, maybe early next week...
TPA3116D2 has a Jack connector while the TDA8954TH has 3 wires connected to small wires/pin thus making the difference in input amplitude as you say (I learn alot, hehehe)
Actually I accidentally did connect to R+ and L-(L+ in real life) for a couple of seconds as I thought it's BTL Mode not checking the polarity, hopefully it does not damage the driver and the amplifier...
if the TDA and TPA has same gain, then it means that TPA performs well with 24vdc than the TDA with 27-0-27vac? The TPA board i have is the one advertise as 2x50w+100w... It has two NE5532 chip tone control, that an advantage in amplifying the input they say. So I'm waiting for the NE5532 Tone Control Board and Hopefully this will improved the sound amplitude
So far I'm on the right track regarding with your instructions...
Thanks!
TPA3116D2 has a Jack connector while the TDA8954TH has 3 wires connected to small wires/pin thus making the difference in input amplitude as you say (I learn alot, hehehe)
Actually I accidentally did connect to R+ and L-(L+ in real life) for a couple of seconds as I thought it's BTL Mode not checking the polarity, hopefully it does not damage the driver and the amplifier...
if the TDA and TPA has same gain, then it means that TPA performs well with 24vdc than the TDA with 27-0-27vac? The TPA board i have is the one advertise as 2x50w+100w... It has two NE5532 chip tone control, that an advantage in amplifying the input they say. So I'm waiting for the NE5532 Tone Control Board and Hopefully this will improved the sound amplitude
So far I'm on the right track regarding with your instructions...
Thanks!
The input connector does not influence the signal level you have at the input (if connected correct). A difference in input impedance of the two amplifiers may make a difference.
As I concluded in my previous posting, it is not obvious that there is a problem. The pre-amp you have ordered may solve the problem.
As I concluded in my previous posting, it is not obvious that there is a problem. The pre-amp you have ordered may solve the problem.
TDA8954D2 power supply
I bought a TDA8954D2 (XH-M251) bluetooth amplifier. I connected it to a power supply that supports the 100 - 240V 2.8A input and 24V 10A output. A blue light was turned on for the Bluetooth enhancer, but no one device (Samsung S7 edge or PrivaIII) was able to find it. Also, when it was connected to the AUX cable, there was no sound signal. Where is the problem?
I bought a TDA8954D2 (XH-M251) bluetooth amplifier. I connected it to a power supply that supports the 100 - 240V 2.8A input and 24V 10A output. A blue light was turned on for the Bluetooth enhancer, but no one device (Samsung S7 edge or PrivaIII) was able to find it. Also, when it was connected to the AUX cable, there was no sound signal. Where is the problem?
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Hi Freeco,
When I search for "XH-M251" I get photo's of a TDA8954 amplifier I know quite well but without Bluetooth. Could you please post a photo of your board?
One information you give confuse me: You use a 24V/10A power supply but this board I know needs a symmetrical supply voltage. Is your power supply symmetrical?
Further, the TDA8954 is not "D2". TDA8954 is manufactured by NXP, the "D2" is known from TPA3116D2 made by TI. Please clarify?
When I search for "XH-M251" I get photo's of a TDA8954 amplifier I know quite well but without Bluetooth. Could you please post a photo of your board?
One information you give confuse me: You use a 24V/10A power supply but this board I know needs a symmetrical supply voltage. Is your power supply symmetrical?
Further, the TDA8954 is not "D2". TDA8954 is manufactured by NXP, the "D2" is known from TPA3116D2 made by TI. Please clarify?
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