TPA3116 D2 mono amplifier as a stereo system?

A good choice for a stereo amplifier. I have only tried with TPA3118 which is the same chip but less good cooling abilities.
The 100W is in 2 Ohm. If you use 8 Ohm or 4 Ohm speakers, use a 24V/6A "laptop brick" and 10000uF/35V between the brick and the amplifiers. One power supply for both amplifiers.
 
Modification. I will suggest you this mono module instead:
Numerique Puissance Audio Amplificateur Conseil TPA3116 100 w DC 12 v 24 v Mono Canal BTL Out dans Amplificateur de Electronique sur AliExpress.com | Alibaba Group

The reason is, as I just noticed, the board you suggest uses 33uH ("330") chokes in the output filter. 33uH chokes of that type can only handle some 2Arms before saturation and you cannot use the full capacity of the TPA3116 chip.
The board I suggest uses 10uH ("100") chokes that can handle around 3-3.5Arms before saturation. Then you have more output power.
 
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Thanks for your feedback @FauxFrench.

If I see this correctly the mentioned mono amp has the following specification:

Chip Type: TPA3116D2
Supply voltage: dc12-26v
Output Power: 100W
SNR: 100db
Channels: Mono
size: 79 * 54 * 16MM

Where do you see that it has 2 Ohm?


I got a couple of newbie questions if you don't mind as this is the first time I am building a system with 2 mono amps:

- What kind of speakers would you recommend for those amps in a stereo setup? Are speakers with lower impedance generally considered better?

- How do you determine the required power in watt of your power supply for this setup?

- Would there be any benefit of using 2 power supplies, for instance this one, over a single laptop brick? Most laptop power supplies I find are either 15V / 6A or 24V / 5A. I wouldn't mind using a dedicated power supply.

- With "10000uF/35V" I guess you are referring to a power rectifier like this one? One of those would be sufficient to run the 2 mono amps with one power supply?

- How do you implement volume control to simultaneously manage both amps? I guess you use a pre-amplifier for that which could also manage the input source (CD / MP3 etc.)?


Thanks a lot for your advice which is much appreciated.
 
If I see this correctly the mentioned mono amp has the following specification:

Chip Type: TPA3116D2
Supply voltage: dc12-26v
Output Power: 100W
SNR: 100db
Channels: Mono
size: 79 * 54 * 16MM

Where do you see that it has 2 Ohm?
The (exaggerated) 100W have been discussed more times on this forum. TPA3116 is limited by its maximum supply voltage of 26V (applying some margin, 24V). Even with 26V supply it is impossible to have 100W in 4 Ohm (or 8 Ohm for that matter). The theoretical maximum with 26V is some 75W in 4 Ohm. You have to go below 4 Ohm to get 100W out.

of * Ohm
I got a couple of newbie questions if you don't mind as this is the first time I am building a system with 2 mono amps:

- What kind of speakers would you recommend for those amps in a stereo setup? Are speakers with lower impedance generally considered better?
In the past, 8 Ohm speakers were considered "best" because the damping factor with a class AB amplifier would be the highest. With class D, damping factor is no longer an issue. Today, the advantage of 8 Ohm is you can use the speakers on any amplifier. And, the distortion is normally a little better with 8 Ohm, even for class D amplifiers. But, you have less output power than with 4 Ohm.

- How do you determine the required power in watt of your power supply for this setup?
In a following posting.......

- Would there be any benefit of using 2 power supplies, for instance this one, over a single laptop brick? Most laptop power supplies I find are either 15V / 6A or 24V / 5A. I wouldn't mind using a dedicated power supply.
To use the full capacity of an TPA3116 chip you should use a 24V supply. Two separate supplies leave a marginal advantage due to very little interference from one channel on the other. The difference may be difficult to notice in practice.
I have the power supply you suggested. It lasted some 10 minutes before breaking down! I will suggest you this one instead: AC 100 240 V a 24 V DC 6A 150 W alimentacion AC DC modulo interruptor G08 gran valor abril 4 en Fuente de Alimentacion Conmutada de Mejoras para el hogar en AliExpress.com | Alibaba Group
, or a "brick" with a casing.

- With "10000uF/35V" I guess you are referring to a power rectifier like this one? One of those would be sufficient to run the 2 mono amps with one power supply?
If you use a "brick" power supply, the output is already DC so the rectifier part is not needed. But, good decoupling capacitors are important for a powerful bass. How much capacitance in the decoupling depends on the amplifier power, the speaker impedance and the "brick" regulation speed. I normally use around 10000uF.

- How do you implement volume control to simultaneously manage both amps? I guess you use a pre-amplifier for that which could also manage the input source (CD / MP3 etc.)?
All you need is a stereo potentiometer with 2x5KOhm resistance. Personally I use a good headphone amplifier with a volume control as pre-amp. The headphone amp. is feed from a separate DAC controlled by optical toslink from a BlueTooth receiver module. I only stream music from various sources.

Lastly, the quality of the mono PBTL module I suggested. I have several TPA3116 and 3118 modules that perform without such noise described at YouTube. I do not have that particular module myself.
The module you suggested seems very fine APART from a weird choice of 33uH chokes when TI recommends 10uH. 33uH chokes can stand considerably less output current than 10uH such that the 33uH chokes become a limiting factor for the output power. Therefore, I suggested the other module but without knowing it appears to have a noise problem.
 
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Thanks for your detailed response @FauxFrench.

I think there are not many mono amp options available with that chipset and power range.

So let's settle on 2 units of the TPA3116DA 100 watt mono amplifier for simplicity... :)


I read an interesting article last night that explained how to choose the right speakers for your amp in terms of power. Considering that this setup will be used for normal music listening in a room of roughly 50 m3, I think the following applies:


"If you are mainly doing light dance music or voice, we recommend that the amplifier power be 1.6 times the Continuous Power rating per channel. If you are doing heavy metal/grunge, try 2.5 times the Continuous Power rating per channel. The amplifier power must be rated for the impedance of the loudspeaker (2, 4, 8 or 16 ohms). ... So stay with 1.6 to 2.5 times the speaker's continuous power rating."


So if I have 100 watts of power available per channel (which will not be reached in practice) and choose speakers with an impedance of 8 Ohm as you suggested, I would need full range speaker models with the following specification according to this formula (depending on the applied factor):

100 watts / 1.6 = 62.5 watts of continuous power rating per speaker
100 watts / 2 = 50 watts of continuous power rating per speaker
100 watts / 2.5 = 40 watts of continuous power rating per speaker

Does that make sense?


I guess that would then also determine the power supply the should be used:

The AC 100-240 V a 24 V DC 6A 150 Watt model you suggested looks fine.

A laptop "brick" for 24V at 6A would be more expensive.

Another option would be a metal-boxed model, which are bit higher in price with that specification.

Considering the price of the amplifiers, would it be reasonable to choose the model you suggested and then 1 or 2 of those?


Could you recommend a suitable decoupling capacitor board for that setup?


I would also appreciate, if you could suggest a good pre-amplifier board with volume control. USB/MP3 and Bluetooth feature as a source for both amps would be nice (not sure if that is available in that combination)...


Thank you. :)
 
It makes sense and based on the philosophy of not loosing control with the speaker. It is an old discussion if the amplifier or the speaker should be the “strongest”. At heavy amplifier clipping (heavy distortion), the amplifier looses control of the speaker movement such that the coil may deviate from its correct linear movement in the narrow magnet air-gap and the coil may strike the magnet. Such may cause permanent mechanical damage even at a power considerably below the rated power of the speaker. Understand the power rating of a speaker such that it is a power level the manufacturer guarantees the speaker can stand for long with a clean input signal. In reality it can stand more for a short time. It is not so that above that power level the speaker is just burned in a short moment. The magnet strike is more unpredictable because it happens in a fraction of a second.

The "brick" has the advantage of being protected by a casing. It costs around 18 US$. The power supply I suggested 11-12 US$.

One power supply is more than enough for two amplifiers. A posting on how to estimate the size of a power supply is coming up soon.

For the decoupling capacitor board, I need to see if that power supply accepts 10000uF at the output. My "bricks" do. I will try with my power supply sometime today.
 
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Regarding power supplies - there are loads of used (actual) laptop power bricks, ie. 19-20V ones available online. I'd trust those infinitely more than whatever brand new crap you can get from the far east. I say "crap" because you don't wanna be d*cking around with cut-rate stuff when we're talking about things you plug into the mains. But that's just me...

Most of those are made my well-known and highly-regarded OEMs like Delta, LiteOn, AcBel, Astec etc.

Just as a quick example, on the local market over here, i found a company selling a "surplus" of 120W (20V 6A) LiteOn laptop bricks for under 6eu a pop...

Sure, you might have to spend some time looking for "the right thing", but i'd say that's worth it, rather than rolling the dice (with your health / life) on health-/fire-hazards like that chinese stuff. Plus you have the near-certainty they haven't skimped on components (isolation inside the transformer, japanese capacitors etc).

Case in point:
I have the power supply you suggested. It lasted some 10 minutes before breaking down! I will suggest you this one instead: AC 100 240 V a 24 V DC 6A 150 W alimentacion AC DC modulo interruptor G08 gran valor abril 4 en Fuente de Alimentacion Conmutada de Mejoras para el hogar en AliExpress.com | Alibaba Group
, or a "brick" with a casing.
 
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I completely agree with the health and safety implications regarding the power supply. So let's go with a laptop "brick" version, which then leads to the question of the specification so that it can handle those 2 mono amps (and a pre-amp).

JohnAudioTech has reviewed the mono amp model on YouTube and published the pre-clipping power output that can realistically be expected for different speaker loads and supply voltages (at 08:28).


8 Ohm
----------

20v -> 19.5 watt

22v -> 24.5 watt

24 v -> 28.1 watt


4 Ohm
----------

20v -> 34.8 watt

22v -> 45.6 watt

24 v -> 51.8 watt


The question is then which factor should be applied (1.6 - 2.5) to calculate the continuous power rating per speaker that should be used for each channel ?

And the other question is if these amps can be operated continuously at 24v, without running into any heat problems?
 
As promised.....

How to choose the power supply for your class D amplifier module.

Typically less experienced DIYs repeatedly ask about this issue. It is not particularly difficult but requires knowledge of Ohms Law, the functioning of a class D amplifier and a Buck (step-down) power converter and some general electronic overview.

Only one channel (mono) will be considered. If you need two amplifiers (stereo) to operate from the same power supply, you simply double the current capability of the power supply such that also the power rating is doubled.

Important parameters
For deciding the right power supply, the maximum (operational) power supply voltage and the maximum output current (where the over-current protection is activated) of the amplifier need to be known (see the specifications or the chip datasheet). You also need to know if the amplifier operates from a single supply voltage or two symmetrical (+ and -) supply voltages. Next, you have to design for optimum operation with 8 Ohm or 4 Ohm speakers, eventually 2 Ohm speakers for automotive use.

The effective operating voltage
The effective operating voltage (Veff) is the voltage the amplifier can use to generate a sine half-wave.
For class D amplifiers operating in BTL configuration from a single supply voltage it is the single rail-to-ground voltage.
For class D amplifiers operating in SE mode with one speaker terminal connected to ground and a symmetrical supply voltage it is the voltage from one rail to ground.
For class D amplifiers operating in BTL mode with a symmetrical supply voltage it is the voltage from one rail to the other rail, thus, double the voltage from one rail to ground.

This effective operating voltage indicates the maximum peak voltage the amplifier can generate for a sine half-wave. From a sine half-wave peak value to the rms value, the factor 1.41 applies. The rms value is found by dividing the peak value with 1.41.
Though the theoretical conversion factor is 1.41, it is suggested to use the factor of 1.5 when calculating the rms value of a sine half-wave that can be generated from an effective operating voltage (Veff). Then, some output switch drop is taken into account.
As an example, for a BTL-coupled amplifier that can handle a single supply voltage of 36V, the rms value of the sine half-wave that can be generated by the amplifier is 36Veff/1.5=24Vrms.
With the rms voltage of the sine wave signal, the power in a load can be calculated using the expression Vrms*Vrms/Rload. Using the values from the example above: 24Vrms x 24Vrms / 8 Ohm = 72W. Or, for a 4 Ohm load: 24Vrms x 24Vrms / 4 Ohm = 144W.
This way we can calculate how much AC signal power it is possible for the amplifier to generate in the load PROVIDED the amplifier can stand the resulting current.

The maximum current for an amplifier output
This value is more difficult to find in a chip datasheet. Sometimes it is specified as the (peak) current the amplifier can handle at an output, sometimes as the output current where the (over-) current limiter is invoked. Some datasheets are not clear about if the chip can stand the maximum (peak) current on more outputs at the same time.

When we have calculated the maximum output power the supply voltage will allow, we have to compare the resulting current against the maximum current for the amplifier chip. To calculate the maximum peak output current, we simply divide Veff with the load impedance. Veff / 8 ohm for 8 Ohm load and Veff / 4 Ohm for 4 Ohm load.
Using the values from the example above, the peak current value in 8 Ohm will be 36Veff / 8 Ohm = 4.5 Apeak. In 4 Ohm it will be 36Veff / 4 Ohm = 9 Apeak. Let’s assume the amplifier can handle 6 Apeak at the output(s), operation with 8 Ohm load is fine (max. 4.5Apeak) but operation with 4 Ohm load (max. 9Apeak) will result in over-current at a certain output level.
If we know we will use the amplifier from the example above with 4 Ohm speakers, we need to lower the supply voltage (Veff) such that the maximum current at an amplifier output is not exceeded. Reducing the supply voltage (Veff) to 24V means the peak current in 4 Ohm will be 6A and the amplifier maximum current is not exceeded.

Calculating the power supply capacity
When the maximum output power that is possible with a certain supply voltage has been calculated and the maximum current at the amplifier output has been successfully checked, we need to calculate the power capacity of the power supply.
Here, we use the knowledge that a class D amplifier has an efficiency of typically 90%. To be prudent we use 80%.
The classical way assuming test with a constant amplitude sine-wave: The maximum output power from the amplifier is divided by 0.8 (80%) to take amplifier losses into account. Using the values from the example above, 72W in 8 Ohm requires a power supply of 72W / 0.8 = 90W. In 4 Ohm, 144W / 0.8 = 180W.
The realistic way assuming use with music: The power supply capacity (Watt) calculated above is divided by two. Why? Because music has got a “crest-factor” meaning that no music is demanding full power for long. Actually, most music has long passages with rather quiet sound and short passages with powerful sound. Therefore, it is seen as unrealistic to design the power supply for maximum sound level all the time. Clever and competent people estimate the steady-state power supply need to be half of what is normally needed for the maximum power the amplifier can output. The power line decoupling capacitors are handling the need for short but powerful surge currents.
Using the example above with 72W in 8 Ohm will then require only a 45W power supply (half of 90W).

Can we swap 4 and 8 Ohm loads?
Yes, but with two different results. If the amplifier and power supply are optimized (designed) for a 4 Ohm load, you can always use an 8 Ohm load instead – but, you will only get half the output power. No overload. If the amplifier and power supply are optimized for an 8 Ohm load, you can use a 4 Ohm load instead at lower output levels. But at a certain output level, the higher current demanded by the 4 Ohm load will exceed the current capability of the amplifier and perhaps also power supply such that you have an over-current situation.
Therefore, 8 Ohm speakers are the most versatile if you do not need the extra power.
 
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The question is then which factor should be applied (1.6 - 2.5) to calculate the continuous power rating per speaker that should be used for each channel ?

And the other question is if these amps can be operated continuously at 24v, without running into any heat problems?

I checked if the 24V/6A power supply module I suggested could handle 10000uF at the output. It can. I tested two power supply modules with a TPA3116 amplifier as load. Worked!

I agree with Krohn and you that the "brick" is the most safe and simple. As your output filter chokes will current-limit the output power to around 20W in 4 Ohm and the supply voltage limit is 32W in 8 Ohm, you may go for a cheap 19-20V "brick" with standard 90W capacity in particular for 4 Ohm speakers.

The continuous power rating factor of 1.6 or 2.5 is only to be used as a guideline when you initially decide how to spend your budget on an audio system.
You probably already have some speakers. Now you want to make your second DIY amplifier. You can use this DIY amplifier on your existing speakers. It will work well even if you are far away from 1.6 or 2.5 as the power rating factor. It is just not optimum balance from an economical point of view. To comply with these factors would require you to change amplifier if you listen to a different type of music.

These modules will not overheat as long as you keep the speaker currents below the saturation current of the output chokes. These modules have good heatsinks and TPA3116 is known for little heating in particular in PBTL (mono) configuration. The worst you can do is to put the amplifier modules in a small fully enclosed box. Then, the temperature inside the box can build up to impressive levels. Use vents and eventually a slow running, low noise fan (I can't hear my $3 12V fan running on 6V) to ensure a flow of air.


As a power line decoupling module, I can suggest: Lusya Amplificateur Redresseur Filtre Conseil DC Double Audio Module D'alimentation DIY KITS/Fini dans Amplificateur de Electronique sur AliExpress.com | Alibaba Group
It can be supplied as a kit such that you can adapt it for AC or DC input and single or symmetrical supply voltage(s).
 
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P.S.: The other mono amp that you mentioned seems to suffer from some quality issues.. Not sure if the reviewer was just unlucky with the samples they sent him...
The guy in the YT review mentions he uses a common ground for his speakers (big no no for class D and running in BTL) and at first he did not ground half of the differential input...... doing it did not even change the sound; LOL

I have used this board for a subwoofer and it sounds fine!

\\ lastest (?) version of this board has a 3300uF 25V 'nichicon' cap


\\\ I would not spend much money on the power supply: 24V does not give much more then 19V as 3dB down from max volume allready uses half the power. I like the 19V 3.14A HP laptop adapters best and they seem to be powerful enough even for my 2.1 dual chip board with 2Ohm (pbtl) subs and 5Ohm tops.
 
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Thanks for your great explanations @FauxFrench. As this is my first DIY project, your assistance is much appreciated... :)

I currently only have a pair of small 6 Ohm cube speakers, which will only do for testing and even don't show the continuous power rating. Building some speakers will be the next project... ;)


So if we sum this up, I should be fine with a standard 20v 4.5A 90 watt laptop power supply like this one (or similar brand manufacturer) for 4 Ohm speakers, right?


Considering Think's comment and friendly advice brings me back to the amp model question:

Should I get the originally proposed version or the alternative model that you suggested?

Here is an example of a stereo setup with the model you suggested... :)


For the power line decoupling module, would I need 1 or 2 units?


Which then leads to the question how to properly connect the 2 amps with the power supply and the capacitor board(s)? I guess I would need something like a 1-to-2 cable splitter and 2 female connectors that should support 20v for the case.


So far I have not spent much thought on the amp housing, but I am not planning anything fancy here. This should be functional and will likely just be mounted on a board with a protective acrylic glas on the top for free airflow.
 
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So if we sum this up, I should be fine with a standard 20v 4.5A 90 watt laptop power supply like this one (or similar brand manufacturer) for 4 Ohm speakers, right?
Right. BUT, almost all power adapters have a Chinese origin like the one you suggest. It is difficult to say if one is clearly better than other, even for adapters supplied by brand names. All mine appears to have a Chinese origin and I have had no accidents. Only my 24V/4A board stopped working.
The price for the one you suggest is in FR, USD 12.69. That I find rather expensive. The price should be around 9-10 USD.
For 8 Ohm speakers I would go for 24V, 5A or 6A (USD 13-14, USD 18).

Considering Think's comment and friendly advice brings me back to the amp model question:
Should I get the originally proposed version or the alternative model that you suggested?

I would go for the module tested by Think (alternative model). Better output filter chokes.

Here is an example of a stereo setup with the model you suggested... :)

Seems to work well there.

For the power line decoupling module, would I need 1 or 2 units?

You need one power line decoupling module per power supply. I use one power supply (and one power line decoupling module) for two amplifier modules and I will suggest you to do the same.

Which then leads to the question how to properly connect the 2 amps with the power supply and the capacitor board(s)? I guess I would need something like a 1-to-2 cable splitter and 2 female connectors that should support 20v for the case.
I would cut-off the DC-plug and connect the wires from inside the cable directly to the power line decoupling module.

So far I have not spent much thought on the amp housing, but I am not planning anything fancy here. This should be functional and will likely just be mounted on a board with a protective acrylic glas on the top for free airflow.
Fine. I use open boards as I do not use each amplifier for very long. New experiments are always ahead.
 
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Great, so to summarize:

1 x 20v 4.5A 90 watt laptop power supply for 4 Ohm speakers

or

1 x 24V 5-6A 120 watt laptop power supply (which seems to be the standard specification) for 8 Ohm speakers

---------

2 x TPA3116 Mono Amps -> the model that you suggested

----------

1 x power line decoupling module

Is there any advantage of buying the DIY kit over the soldered version?

-------------

If I wanted to keep the power supply cable intact for other projects, I could use a DC adapter like this, correct?



Which basically leaves me with the last question of the setup:

Could you recommend a pre-amplifier board that could handle volume control and source input simultaneously for both amps?
 
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Great, so to summarize:

1 x 20v 4.5A 90 watt laptop power supply for 4 Ohm speakers
or
1 x 24V 5-6A 120 watt laptop power supply (which seems to be the standard specification) for 8 Ohm speakers


Yes!

2 x TPA3116 Mono Amps -> the model that you suggested

Yes!

1 x power line decoupling module
Is there any advantage of buying the DIY kit over the soldered version?


Yes! I did not find a rectifier board for a single voltage with sufficient capacitance. This board is intended for symmetrical voltages with a transformer input. You can use that as well for a single DC voltage.
If you buy the kit, you may modify it according to your preferences. I can tell you how.
Kit or soldered version as you prefer.

If I wanted to keep the power supply cable intact for other projects, I could use a DC adapter like this, correct?

You can use such connectors if you prefer not to cut the DC plug.

Which basically leaves me with the last question of the setup:
Could you recommend a pre-amplifier board that could handle volume control and source input simultaneously for both amps?


I am very bad with pre-amplifiers because I do not use one. I use: BlueTooth receiver with optical output -> optical input of my DACMagic (Cambridge) -> Musical Fidelity headphone amplifier with volume control -> DIY amplifier. I use different sources to stream FLAC files via BlueTooth.
My only advise is a pre-amp with at least NE5532/34 OP-AMPs. In my opinion, tone-controls (bass/treble) are little important with decent speakers.

I guess the section "Analog Line Level" on this forum has got specialists in pre-amps.

Good luck and let me know, eventually with a PM, when you have got the stuff and is ready to assemble the rectifier board if needed.

FF
 
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Better use 19/20V with 25V caps or you might have to replace them later (had this problem with 1 board); the difference in max sound level/output will be minimal (<2dB)

Based on my practical experience with a couple of 3116 boards: Just a standard 65W/3.14A laptop supply will be fine to power both when used for music into regular 8Ohm speakers instead of sinewaves into resistors/static loads.

You can use any stereo preamp, as the L and R outputs go to the mono boards. (assuming you want to play stereo)

You can use a simple and cheap DPDT switch as input (or output) selector for 2 sources. Or use a (audio) selector switch (ie from an old reciever/ preamp) for more sources.
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