TPA3255 - all about DIY, Discussion, Design etc

[daniboun]

You can operate @40V DC with your 3E Audio board yes. I would say 36/40V is a good option. I personnaly won't go more to avoid overheat.

 

[Kjeldsen]

DC = 1,41 x AC...

//

Minus the loss over diodes in the bridgerectifier 2x0,7 volt

 

[vitopro]

I see yours came with Nichicons..mine came with ELNAs. Did you swap them out?

Pete

No. They are stock.

 

[claredes]

You can operate @40V DC with your 3E Audio board yes. I would say 36/40V is a good option. I personnaly won't go more to avoid overheat.

Great.
I am testing a power transformer that I have and after rectifying it it gives me approximately 40V.
I was going to buy an SMPS power supply and use it outside the case, but this idea of an external power supply was bothering me a lot.

 

[turion64]

clardes, I’m in agreement with daniboun about the voltage range. I used both a 36V and 48V SMPS with the 3e boards (old and new version of the amp) and 48V just heated the heatsink and output coils to an uncomfortable level. The 36V SMPS is fine and everything only gets moderately warm. I’m driving 6-8 ohm speakers as a reference.

 

[claredes]

clardes, I’m in agreement with daniboun about the voltage range. I used both a 36V and 48V SMPS with the 3e boards (old and new version of the amp) and 48V just heated the heatsink and output coils to an uncomfortable level. The 36V SMPS is fine and everything only gets moderately warm. I’m driving 6-8 ohm speakers as a reference.

What about 40V versus 4ohms ??
I believe that with load these 40V should drop a little, being optimistic, I believe it drops to 38V.
But supposing it doesn't drop and keep the 40V. Is 40V and 4ohms safe?

 

[daniboun]

Great.
I am testing a power transformer that I have and after rectifying it it gives me approximately 40V.
I was going to buy an SMPS power supply and use it outside the case, but this idea of an external power supply was bothering me a lot.

This one in revision 3.3 is great and has a nice ripple ! (LLC + Softstart)

SMPS connex 300RS 36V (up to 40V max) and work fine with any 3E Audio Board and other TPA325X

You can also get a Murata PQ250-36

36V / 250W that is also very good for about 65 euros @ DIGIKEY

about $39 @ Components Store )


PQC250-36, Murata Power Solutions PQC250-36 in Stock available. Buy PQC250-36 with best price at Components-Store.com

An externally hosted image should be here but it was not working when we last tested it.

 

[claredes]

This one in revision 3.3 is great and has a nice ripple ! (LLC + Softstart)

SMPS connex 300RS 36V (up to 40V max) and work fine with any 3E Audio Board and other TPA325X



You can also get a Murata PQ250-36

36V / 250W that is also very good for about 65 euros @ DIGIKEY

about $39 @ Components Store )

Yes, I understood.
But I will use a linear power supply.
Anyway, I saw that I will be safe close to 40V.

 

[arizonavideo]

I receive 3255 amp the other day. It is the ebay YJ-D01 with the TPA3255.



I have a 400 VA 47V spply.


Out of the box I just don't have much love for the sound. It has the NE5532 pre amps.



I did upgrade to the LME49720NA which did make it sound a fair bit better. I guessting the 5532 might be fake.



The marking on the back are different with the tow opamps. I don't have a good way to tell if the 5532 are fake.

 

[Tattenbach]

48v psu to much for tpa3255?

As I have interruption with this psu on my Ayima tpa3255, I ask if I should change to a opamp which takes higher current or has someone changed caps.:

 

[vitopro]

I'm found my old connexelectronics A1000SMPS suitable for TA3020 1000W. It produces a +-60 voltage with a trimmer regulation i can step down to about +-48 V. My question is: may i use a single rail as TPA3255 psu or is better to buy a single rail PSU?

 

[drMordor]

My question is: may i use a single rail as TPA3255 psu or is better to buy a single rail PSU?

Yes, this is normal.

 

[chriscam]

pffb question

Hi there,

Didn't want to start yet another 3255 thread so am posting this Q over here. I'm looking at implementing pffb with my tpa3255 design but am wondering about the following: in a standard single rail setup the outputs float at 1/2Vpp as shown in the image below. My Q is whether I should worry about the dc unbalance over R_fb assuming the output of the opamp buffer sits at GND ?

 

[bucks bunny]

To make this work, you op-amps require +/- supplies.

 

[cdsgames]

I have made more progress . This new FFT was made after optimizing zobel network . Instead of one cap and one R I used 3 caps in parallel with 3 R in parallel . THD is 0.00045


Note also the absence of H3




I think that at this point this is the best measured TPA3255 (at 5W , 1Khz , 8R)

 

[bucks bunny]

I wonder which soundcard you use that generates <120dB H3.

 

[bucks bunny]

I think that at this point this is the best measured TPA3255 (at 5W , 1Khz , 8R)

Inspires me to do some measurements of my own.

 

[cdsgames]

I wonder which soundcard you use that generates <120dB H3.

Simple I am using my own DAC Katana (modified) thats rated at -120 THD at full signal



Also I ordered a special oscillator thats rated at -135 from one of the venders on diyforums .

 

[chriscam]

To make this work, you op-amps require +/- supplies.

Thanks, I know, please see below where you will find the opamps use symmetric supplies. The question concerns the 1/2Vpp the tpa3255 outputs are on - typically 25.5V with a Vpp of 51V. Doesn't the dc imbalance between the driving opamp output (0V) and the OUT_X (Vpp/2) mess up the control loop ?

 

[Peterwitkin]

Hello guys.

Does Anyone knows how to bypass input OP AMP on
The 3eaudio 2x260w board AMP ?

A picure could be a big help.

I do not need a lot of power and i would like to try to use it directly with a topping dx7pro (balanced output).

Thanks