Has anyone tried the TPA3255 Class D Amplifier board?

[SanjeevM]

FWIK the TPA3255 chip is actually four high quality Class D amplifiers embedded on a single chip, which can be used as 4 single channels or 2 stereo or a single mono channel, depending upon the jumpers you set. It provides 260 Watts stereo power into 4 ohm speakers at 1% thd. THD + N at 1W 4ohm is 0.006% which is very low. Rest of the details you can see from its datasheet.

The chip is sold by Texas Instruments as an fully assembled Evaluation board at $149 with high quality components. Surface mounted components are standard. It has a very high PSRR, so simple switch mode supplies are good enough, without having to build large Trafo and huge cap banks. No heatsinks are needed other than a small one mounted on the board. The cost structure is very attractive...
TI Eval board ... Re 9000 + customs (or free in hand baggage)
SMPS Meanwell 350W -48v or other ..... 3000
Cabinet ..... 2000
Other connectors, wires etc..
So about Rs 15000 will get you this high quality amplifier. Now that Summer is coming, this amp with over 90% efficiency will not heat up your room It is said that the chip doesn't even get warm ar normal listening levels.

This chip is getting a lot of praise for its sound quality and configurability in forums such as diyaudio.com etc.. Earlier, Class D chips were thought as mid-if, but with this chip, there is serious competition to Class AB Amps.I have used its smaller brother, the TPA3251, and I like it very much.

Has anyone tried the TPA3255 chip / board?

http://www.ti.com/product/tpa3255/datasheet

 

[SanjeevM]

I guess no one has tried this wonderful board ... *sigh*

 

[surfatwork]

I haven't tried the 3255, but have tried the tda8932, which gives terrific sound quality for loose change (Rs.300 for a mono board!) . Granted it isn't as powerful as the 3255, but IMO, most people don't really need 260W.

 

[SanjeevM]

Completely agree. I am using 3251 for the sheer performance and simplicity, but not for power.

Before the 3251, I was using TPA3118D2, and found it to be very musical. The 3251 is a world apart.

Theoretically, a Class A should sound the best, but if you do a comparison with a good Class D, you will be surprised to see how good D now is.

In fact, before going the big-D way, I did go with my PCH player and music to one Class A builder, and was surprised to find that D held more promise.

Now, I feel, 3251 surpasses. One could say, maybe that wasnt a good A, and he may be right, but my ears tell me differently. Maybe I am biased; could be !!

But one should try it out !

 

[vizeta]

I am the one who got two TPA3255EVM boards and almost completed the Amp build using those
Using these boards in PBTL config.
Planning to post my experience and build pictures. I need some more time to create a thread for that.

Initially, I ordered single board and used it in BTL config (2 channel mode) and I was very happy with the performance.
Then, I ordered one more board to build Dual mono config (each board in PBTL mode) but I felt for some reason (maybe psychological) the performance is not that great (compared to the single EVM board on BTL mode).

My test setup : RPI3+Allo Boss DC >>> Allo stepped attenuator >>> TPA3255EVM PBTL >>> Heco Victa 700
(each board is powered by a separate Mean Well 48V-350W SMPS)
Let me know if you need any specific info.

 

[vizeta]

Here you go>>

 

[vizeta]

Here you go My Dual Mono TI TPA3255EVM based Class D Amplifier build

 

[SanjeevM]

Nice work, vizeta. I will also try out this chip.

I have RPi3B + BossDAC 1.1. The dac feeds 3251 directly. Should I go for Meanwell 350 smps or a linear unregulated PSU will be better?

 

[SanjeevM]

I mean, for the 3255 board.

 

[SanjeevM]

Do you get any pop or click at startup?

My 3251 has just a small startup click.i dont have to use the reset button.

 

[vizeta]

Nice work, vizeta. I will also try out this chip.

I have RPi3B + BossDAC 1.1. The dac feeds 3251 directly. Should I go for Meanwell 350 smps or a linear unregulated PSU will be better?

I am also using it with RPi3B + BossDAC 1.1 (connected to Allo SMPS).
I am very happy with Meanwell 350W SMPS and since I did not try the board with linear PSU I can't comment on any benefit of using linear PSU. Initially, I was planning to get toroid transfer to run one board on linear and other board on SMPS and compare the result. But the long wait time to source the trafo, good quality diodes and filter Caps discouraged me to go that way.

 

[vizeta]

Do you get any pop or click at startup?

My 3251 has just a small startup click.i dont have to use the reset button.

Yes actually. I can hear a small turn-on click but I am concerned about turn-off click (I think gradual voltage drop of SMPS Caps+Board caps make it worse). Its little louder compared to turn-on click.

Planning to use a circuit to engage reset switch (probably a MCU sensing main supply and introduce turn-on delay and engage Reset before capacitors loose charge in case of powercut/off events) to avoid pop sound during power-on/power-off events.

 

[SanjeevM]

I tried powering the Boss 1.0 dac with a power bank. The result was good. Havent tried it with 1.1 as yet, due to connector problem.