6 Channel TPA3116 + DSP

[grahamgraham]

Morning all!

Since my stalled project to sync several class D boards for bi-amping is at the mercy of international delivery I've turned my attention to another project.

It is a stereo tri-amped active DSP system (2 x 4" mid [8ohm]/ 1" tweeter [4ohm] satelites & 2 x Tang Band 6.5" [4ohm] subwoofers - sealed) and I think I have found the board that will do the trick for it:

AIYIMA TPA3116 Amplifier Audio Board 5.1 Channel Digital Power Amplifier Board 50W*4 100W*2 DIY 5.1 Home Theater DC12 24V-in Amplifier from Consumer Electronics on AliExpress - 11.11_Double 11_Singles' Day

It looks quite tidy, the output inductors look fairly chunky and similar to Wurth counterparts which might indicate they have a similar saturation point of around 6A (744750420100 | Wurth 10 μH +-20% Ferrite Power Inductor, 6.2A Idc, 15.5mΩ Rdc WE-FAMI | RS Components). I will be using the balanced in connections via some better quality coupling caps from 3 x Sure ADAU1701 DSP boards.


The subs would be run from the two PBTL chips whereas the mids and tweeters will have chip each to share.


What do you guys think of it? I have ordered it just to see what it's like for now.


As far as PSU goes I was looking at this but have been told this is overkill:

SANPU SMPS 24V 500W DC LED Switching Power Supply 20A Constant Voltage Single Output 220V 230V AC/DC Transformer Driver Indoor-in Switching Power Supply from Home Improvement on AliExpress - 11.11_Double 11_Singles' Day

But I would prefer something sold in Europe that has to conform to our safety regs even tho it is a little under-powered. Could I use bulk caps to get round this?

MEAN WELL LRS-350-24 Switching Power Supply SMPS 24V 14.6A 350W - Audiophonics


This is not a big budget build otherwise I would have looked at other boards but finding balanced ins and multi-channel is difficult to begin with!

 

[Turbowatch2]

Don´t use Sure DSP. It suck´s.
This one, at close range, is much cheaper. It has all the stuff Sure forgot and you can only add at huge cost´s.
ADAU1701-2In4Out | 3e Audio

Two of them should be enough.

 

[grahamgraham]

Don´t use Sure DSP. It suck´s.
This one, at close range, is much cheaper. It has all the stuff Sure forgot and you can only add at huge cost´s.
ADAU1701-2In4Out | 3e Audio

Two of them should be enough.

Brilliant, I had looked at them before but had disregarded them due to lack of balanced input however, this system is largely bluetooth based and I can use the I2S input from a board. Thanks Turbo!

Did you have any thoughts on the board or power supply at all?

 

[chermann]

Hi Graham


i used the PSU meanwell LRS350-36V on a TPA3255 board/amp. the psu is not too expensive and works well.


the board i don´t know..be careful before you use good speakers. make tests before..

chris

 

[grahamgraham]

Hi Graham


i used the PSU meanwell LRS350-36V on a TPA3255 board/amp. the psu is not too expensive and works well.


the board i don´t know..be careful before you use good speakers. make tests before..

chris

Thanks, yes, the amp is an unknown. I am not getting my hopes up too much!

Do you think the PSU will have enough grunt for this application?

 

[Neil Davis]

I've used that 6-channel amp for two different projects. It works fine, but you will need to be very careful about running your grounds or else you will have a lot of noise from those 6 amps switching at the same frequency. This link shows the amp I use for my computer speakers, which makes them active 3-ways.

I've got another version underway with that amp shown in the picture. Both of these projects use the "Revision 2" stereo 3-way ADAU1701 board described in this link. There is a new version of the board on the workbench, awaiting some parts, that uses the $16 ADAU1701 learning board. That one should be very easy to build, as it has no SMD parts.

 

[grahamgraham]

I've used that 6-channel amp for two different projects. It works fine, but you will need to be very careful about running your grounds or else you will have a lot of noise from those 6 amps switching at the same frequency. This link shows the amp I use for my computer speakers, which makes them active 3-ways.

I've got another version underway with that amp shown in the picture. Both of these projects use the "Revision 2" stereo 3-way ADAU1701 board described in this link. There is a new version of the board on the workbench, awaiting some parts, that uses the $16 ADAU1701 learning board. That one should be very easy to build, as it has no SMD parts.

Thanks Neil! Wow, this board has been around for a while, I'm surprised.

Are the chips not in sync mode? I suppose that is something that could be done fairly easily. Using balanced in to each input I will have a decent chance of avoiding unwanted noise.

I noticed that the one I have (black PCB) is version 3.1 of the design, not sure what the difference is. Maybe they address the syncing? Time will tell.

What PSU would you recommend I don't recognise the one in your image.

Cheers!

 

[Neil Davis]

The noise problem is due to switching currents in the ground lines, and balanced inputs won't fix the problem. There is actually an error in the picture--it shows one of those LM2596 DC-DC converter boards to provide the 5V for the DSP from the 24V. That configuration will result in lots of noise, even with no input. There is also lots of "chatter" whenever the Bluetooth interface is used to control the DSP. I need to replace that non-isolated DC-DC converter with an *isolated* 24V-5V DC-DC converter so that the DSP and amp only share a ground at the amp input connection. I forgot that I had done that on the other amp that I made.

I use smaller power supplies, in the 75W-200W range, because there is no way you will ever need 50W continuous from each amp for music. The power supply in the picture is just a $10 65W supply from MPJA. This amp will be for a 4" tall 3-way computer monitor stand using 2-1/2" "subwoofers", so I didn't need a lot of power. The other amp uses the Meanwell UHP-200, which is 200W but it is about half the size of their other 200W supplies.

 

[grahamgraham]

The noise problem is due to switching currents in the ground lines, and balanced inputs won't fix the problem. There is actually an error in the picture--it shows one of those LM2596 DC-DC converter boards to provide the 5V for the DSP from the 24V. That configuration will result in lots of noise, even with no input. There is also lots of "chatter" whenever the Bluetooth interface is used to control the DSP. I need to replace that non-isolated DC-DC converter with an *isolated* 24V-5V DC-DC converter so that the DSP and amp only share a ground at the amp input connection. I forgot that I had done that on the other amp that I made.

I use smaller power supplies, in the 75W-200W range, because there is no way you will ever need 50W continuous from each amp for music. The power supply in the picture is just a $10 65W supply from MPJA. This amp will be for a 4" tall 3-way computer monitor stand using 2-1/2" "subwoofers", so I didn't need a lot of power. The other amp uses the Meanwell UHP-200, which is 200W but it is about half the size of their other 200W supplies.

Interesting. I had planned on using the Mornsun b0505s-1w type DC-DC isolators for both BT and DSP boards coming from one of the LM2596 boards you used, hopefully that will keep things clean. They will all have their own ground but I am not sure of the power consumption of the boards so I don't know if they will be enough.

Which isolating DC solution are you going to switch to?

Are there any other provisions I should take to help keep noise down?

 

[daemonsgr]

can amps like these be used with 105++ db CDs? (110db maybe) or we are asking for trouble?

 

[grahamgraham]

can amps like these be used with 105++ db CDs? (110db maybe) or we are asking for trouble?

Compression drivers?

Yes, but I have no idea how this amp functions just yet. With any class-d Chinese design board the gain will be jacked up high leading to noise. With a high sensitivity CD that would be unbearable. So expect to have to do some fiddly soldering with SMD resistors. Balanced inputs would further reduced noise potential but as we have been discussing it depends if it is connected to any other board or if it shares the same PSU.

I wouldn't.

 

[Neil Davis]

Interesting. I had planned on using the Mornsun b0505s-1w type DC-DC isolators for both BT and DSP boards coming from one of the LM2596 boards you used, hopefully that will keep things clean. They will all have their own ground but I am not sure of the power consumption of the boards so I don't know if they will be enough.

Which isolating DC solution are you going to switch to?

Are there any other provisions I should take to help keep noise down?

I've got a 5V to 5V isolated converter on that PCB to power a WiFi module, but the DSP also needs to be isolated. I use the Meanwell modules: SMU02L-05 for 5V to 5V and SPB05B-05 for 24V to 5V. They about about $9 or $10 each from Digikey or Mouser. 3W output is plenty--it's over twice what is needed, even if you have radios (WiFi and/or Bluetooth). You don't need the LM2596 board--just use the SPB05B-05 to go from 24V to 5V.

That Mornsun module should work OK for the DSP, but it does not provide enough current for Bluetooth or WiFi modules.

 

[grahamgraham]

I've got a 5V to 5V isolated converter on that PCB to power a WiFi module, but the DSP also needs to be isolated. I use the Meanwell modules: SMU02L-05 for 5V to 5V and SPB05B-05 for 24V to 5V. They about about $9 or $10 each from Digikey or Mouser. 3W output is plenty--it's over twice what is needed, even if you have radios (WiFi and/or Bluetooth). You don't need the LM2596 board--just use the SPB05B-05 to go from 24V to 5V.

That Mornsun module should work OK for the DSP, but it does not provide enough current for Bluetooth or WiFi modules.

Cheers, man. I already have a step-down board so I think I'll use 5v-5v to keep costs down. Two 1w isolators for each DSP and a 2w for the bluetooth.

Incidentally I used a 1w 5v DC-DC for a csra64215 build and the range was poor. Could this have been the reason?

Seeing as you did not use these amp boards with any anger you may not have bothered but do you think the large capacitor needs to be upgraded?

 

[Turbowatch2]

When I put such combination of modules together, I never build it at once with all components.
It is much better to work from the basic amp and PS, if this works as expected and is noise free, you can connect the next stage. In this case the DSP with power supply. If anything is still well and working, you might try your luck by throwing in the Bluetooth module.
This way you will waste no time with trouble shooting, ripping things apart and changing modules and PS. Components that have faults can be terminated in the early stage.

Look at the usual questions you read here at the forum every day: "I took this and that, neatly wired it up and now it makes noise I don´t want. How do I fix it?" Endless threads are dedicated to this!
Some builders always have such problems, some never. This has nothing to do with the price of parts or the "luck" of the designer, it is predetermined by the way you start such a build. If you do one wire wrong, the whole project is spoiled.

Anyway, good luck!

 

[Turbowatch2]

If you have two modules that need the same voltage to operate and you fear they could disturb each other, maybe try a very simple solution.
Just separate the outputs by some simple, cheap (1N4001 or 1N4148) diodes. This way the connected modules do not see each other. Usually any module has some kind of buffer for the power supply on board, so you need not add any extra capacitors after the diode. Even better if you can adjust the PS, as you loose .7 volt at the diode.
Sure you can take an isolated PS for each module, but this is not very elegant and might lead to new problems.
The majority of noise problems, in the end boils down to ground issues.

 

[Neil Davis]

Seeing as you did not use these amp boards with any anger you may not have bothered but do you think the large capacitor needs to be upgraded?

No. According to the TDA3116 data sheet, the main filter capacitor should be 100uF or greater for each chip. Using a larger bulk capacitor won't improve the performance, and it may screw up the feedback loop in the switching power supply. If you feel the need to "upgrade" the filtering, add some .001uF and 1uF low ESR ceramic caps as close to the chips as possible, as suggested in section 10.1 of the data sheet.

 

[grahamgraham]

When I put such combination of modules together, I never build it at once with all components.
It is much better to work from the basic amp and PS, if this works as expected and is noise free, you can connect the next stage. In this case the DSP with power supply. If anything is still well and working, you might try your luck by throwing in the Bluetooth module.
This way you will waste no time with trouble shooting, ripping things apart and changing modules and PS. Components that have faults can be terminated in the early stage.

Look at the usual questions you read here at the forum every day: "I took this and that, neatly wired it up and now it makes noise I don´t want. How do I fix it?" Endless threads are dedicated to this!
Some builders always have such problems, some never. This has nothing to do with the price of parts or the "luck" of the designer, it is predetermined by the way you start such a build. If you do one wire wrong, the whole project is spoiled.

Anyway, good luck!

Noted, I will definitely do it like this, I promise.

If you have two modules that need the same voltage to operate and you fear they could disturb each other, maybe try a very simple solution.
Just separate the outputs by some simple, cheap (1N4001 or 1N4148) diodes. This way the connected modules do not see each other. Usually any module has some kind of buffer for the power supply on board, so you need not add any extra capacitors after the diode. Even better if you can adjust the PS, as you loose .7 volt at the diode.
Sure you can take an isolated PS for each module, but this is not very elegant and might lead to new problems.
The majority of noise problems, in the end boils down to ground issues.

Thanks for the tip. Are the diodes on both the voltage and ground lines?

Also, I mentioned this on my 2 x TDA7492 board thread as a possible solution to the noise problem. Would this help or work in that instance?

No. According to the TDA3116 data sheet, the main filter capacitor should be 100uF or greater for each chip. Using a larger bulk capacitor won't improve the performance, and it may screw up the feedback loop in the switching power supply. If you feel the need to "upgrade" the filtering, add some .001uF and 1uF low ESR ceramic caps as close to the chips as possible, as suggested in section 10.1 of the data sheet.

Noted!

 

[NMOS]

Don´t use Sure DSP. It suck´s.
This one, at close range, is much cheaper. It has all the stuff Sure forgot and you can only add at huge cost´s.
ADAU1701-2In4Out | 3e Audio

Two of them should be enough.

Hi

look good

but I need 2 in 4out or 2 in 2out DSP with Rotary encoder + Display


Do you know reliable supplier for this solution ?

I know ALLDSP from our country, but he dont like to sell me

HMAUDIO offer, but I didnt try to import

 

[digitaled]

Noob question. Please dont laugh.
Is it possible to make this or any similar type of 5.1 amp a Dolby compatible.

 

[Turbowatch2]

@diditaled
You take a Dolby 5.1 pre amp and put it in front of your 6-channel amp. Was that your question? But why build a 5.1 Dolby amp? There are AVR receiver out there...

@grahamgraham The diode only in the + (or, with a dual supply + and -) supply line, no diode with ground.
Yes, this diode thing is used with many D-amps. I think it is more a kind of idiot protection you need if you sell worldwide to people that do not have any basic education, like you expect them in most western country´s. I have worked with refugees and now have a different view at our (good) school system.
With D-amps it might even reduce the need to synchronize them.

@NMOS
look for PM