My Dual Mono TI TPA3255EVM based Class D Amplifier build

[vizeta]

Hey Guys,

As Promised, here are details of my TI TPA3255EVM AMP build.


Stage 1:
After reading very encouraging reviews about TPA3255 chip, I decided to try it and ordered a Chinese (black version) from Aliexpress. While this board was in transit I came across the very positive reviews of TI TPA3255EVM module and discount (50%) offer on class D Amp module. I went ahead ordered one module.

The Board was not in stock when I ordered but they shipped it after 20 days they shipped it via Fedex. It was a very painful experience to get it Custom cleared via Fedex. And it took almost 20 days to get it cleared.
But it got delivered around the same time when the Chinese board was delivered via India post

I sold the Chinese board to a very friendly FM here.

I connected the EVM board to my setup and was blown away by the sweet and highly detailed output of the speakers. I used Lagaan, Daft Punk- Random Access Memories and Hotel California Flac files to check the performance.
Test Setup : RPI3+Allo Boss DC >>> Allo stepped attenuator >>> TPA3255EVM BTL mode + Mean Well LS-350-48 >>> Heco Victa 700

Stage 2:

I was so much excited by the performance of the board and diyaudio forum reviews encouraged me to try the board in PBTL config (dual mono).

I ordered one more EVM board and another SMPS to power it.

Then I started hunting for a decent cabinet for the Amp (but was not ready to pay the premium price). I found this PRO POWER G17082UBK 19" Case, ABS, 2U cabinet.

I paid around Rs 3400/- for the same. The ABS material is very easy to work with. it was very easy to make holes and mounting the board.

I am yet to test it fully, but I felt for some reason (maybe psychological) the performance is not that great (compared to the single EVM board in BTL mode).
Will update the thread later with a detailed review of the sound quality.

Here is my build picture:
The Amplifier:




The Power Supply:

I decided to go ahead with dual Mono configuration and to maintain (at least I tried to) I ordered two Mean Well LRS-350-48 (48 Volts 350 Watts) SMPS modules.
Since the Cabinet was not big enough to accommodate 2 x TPA3255EVM boards along with 2 x SMPS modules, I placed SMPS modules inside a Metalic Tea box (Will upgrade it later).




Power Supply Connections:

Now, The next problem was how to connect the SMPS outputs to AMP via a connector (should be able to handle 7+ Amps). The obvious choice was to use Banana connectors. But I don't to take a chance where someone may connect the PSU plugs to Speaker binding posts.

I came across this >> JELEN HP20, 4 pin power connector (IP55). The specs suggest the connector can hanlde upto 30Amp.
I ordered this from aliexpress and used it to connect the PSUs to Amp.

 

[Rud31]

How is the startup of the amps? The Chinese TPA3255 boards don't have speaker protection circuitry thus giving a loud pop on powering up. What about this one?

 

[SanjeevM]

There is a small pop at shutdown. Not speaker busting.

I am using this board since a long time. It's a wonderful amplifier.

 

[vizeta]

How is the startup of the amps? The Chinese TPA3255 boards don't have speaker protection circuitry thus giving a loud pop on powering up. What about this one?

As mentioned by @SanjeevM it makes a small pop at shutdown. But its not too loud to make you think about having a speaker protection broard added with it.

 

[sunilmani]

In a class D amplifier, i am coming across folks who state that a linear power supply makes a world of difference to the quality of sound. Has anyone here verified it ?

 

[RaahulT]

How is the performance of the amp/chip over the time?
Would you suggest to go for it? Any precautions to be taken in design

 

[RaahulT]

How is the performance of the amp/chip over the time?
Would you suggest to go for it? Any precautions to be taken in design

@vizeta

 

[vizeta]

How is the performance of the amp/chip over the time?
Would you suggest to go for it? Any precautions to be taken in design

I am not using these boards in PBTL config (dual mono) now. One board is being used in my Bedroom setup : Squeezbox Touch >> TPA3255EVM (In BTL) >> Wharfedale 9.1

I have never faced any issue with the amp and am satisfied with the performance.


I think the Board and Power supply connections are pretty straightforward. If you are planning to use it with 48V SMPS, just check the output voltage with a good Voltmeter/Multi-meter to make sure that voltage should not exceed 48V. Some of the Caps on the board are rated for 50volts

 

[RaahulT]

I am not using these boards in PBTL config (dual mono) now. One board is being used in my Bedroom setup : Squeezbox Touch >> TPA3255EVM (In BTL) >> Wharfedale 9.1

I have never faced any issue with the amp and am satisfied with the performance.


I think the Board and Power supply connections are pretty straightforward. If you are planning to use it with 48V SMPS, just check the output voltage with a good Voltmeter/Multi-meter to make sure that voltage should not exceed 48V. Some of the Caps on the board are rated for 50volts

Thanks.

 

[sound1]

In a class D amplifier, i am coming across folks who state that a linear power supply makes a world of difference to the quality of sound. Has anyone here verified it ?

I did and it was very true iny case.

 

[vizeta]

I did and it was very true iny case.

Can you please share the details of the LPS you connected to a Class D Amp?

 

[SanjeevM]

In the 3255 forums on diyaudio people have stated that the chip has high psrr, so
LPS will not make much of a difference. They recommend the Meanwell 35v or 48v smps psu.

 

[sound1]

Can you please share the details of the LPS you connected to a Class D Amp?

Please check this post: https://www.hifivision.com/threads/thread-on-hypex-ncore-amps.26731/#post-374964

It was my personal experience while experimenting with SMPS, and as always it may not be true for everyone.

 

[vdevgon]

Still

Hey Guys,

As Promised, here are details of my TI TPA3255EVM AMP build.


Stage 1:
After reading very encouraging reviews about TPA3255 chip, I decided to try it and ordered a Chinese (black version) from Aliexpress. While this board was in transit I came across the very positive reviews of TI TPA3255EVM module and discount (50%) offer on class D Amp module. I went ahead ordered one module.

The Board was not in stock when I ordered but they shipped it after 20 days they shipped it via Fedex. It was a very painful experience to get it Custom cleared via Fedex. And it took almost 20 days to get it cleared.
But it got delivered around the same time when the Chinese board was delivered via India post

I sold the Chinese board to a very friendly FM here.

I connected the EVM board to my setup and was blown away by the sweet and highly detailed output of the speakers. I used Lagaan, Daft Punk- Random Access Memories and Hotel California Flac files to check the performance.
Test Setup : RPI3+Allo Boss DC >>> Allo stepped attenuator >>> TPA3255EVM BTL mode + Mean Well LS-350-48 >>> Heco Victa 700

Stage 2:

I was so much excited by the performance of the board and diyaudio forum reviews encouraged me to try the board in PBTL config (dual mono).

I ordered one more EVM board and another SMPS to power it.

Then I started hunting for a decent cabinet for the Amp (but was not ready to pay the premium price). I found this PRO POWER G17082UBK 19" Case, ABS, 2U cabinet.

I paid around Rs 3400/- for the same. The ABS material is very easy to work with. it was very easy to make holes and mounting the board.

I am yet to test it fully, but I felt for some reason (maybe psychological) the performance is not that great (compared to the single EVM board in BTL mode).
Will update the thread later with a detailed review of the sound quality.

Here is my build picture:
The Amplifier:
View attachment 26006View attachment 26015View attachment 26013



The Power Supply:

I decided to go ahead with dual Mono configuration and to maintain (at least I tried to) I ordered two Mean Well LRS-350-48 (48 Volts 350 Watts) SMPS modules.
Since the Cabinet was not big enough to accommodate 2 x TPA3255EVM boards along with 2 x SMPS modules, I placed SMPS modules inside a Metalic Tea box (Will upgrade it later).

View attachment 26008


Power Supply Connections:

Now, The next problem was how to connect the SMPS outputs to AMP via a connector (should be able to handle 7+ Amps). The obvious choice was to use Banana connectors. But I don't to take a chance where someone may connect the PSU plugs to Speaker binding posts.

I came across this >> JELEN HP20, 4 pin power connector (IP55). The specs suggest the connector can hanlde upto 30Amp.
I ordered this from aliexpress and used it to connect the PSUs to Amp.

View attachment 26010View attachment 26009View attachment 26012

have these or sold or planning to sell, please let me know thanks?

 

[sunilmani]

As mentioned by @SanjeevM it makes a small pop at shutdown. But its not too loud to make you think about having a speaker protection broard added with it.

I know if too late, but i found this on another forum posted by cyberpit.

TPA3255 - all about DIY, Discussion, Design etc

Can be modified for headphone amp? My God !!!😵‍💫😵‍💫:violin:

www.diyaudio.com

You may want to take a look.