What is wrong with TPA3255?

[xrk971]

Thanks for the tip. Will get some on my next order. Would you happen to have part number handy?

 

[chermann]

Thanks for the tip. Will get some on my next order. Would you happen to have part number handy?

Hi X


here it comes...493-10815-1-ND


i tried it at the input rca instead of silmic 2 and the dark nichicon muse. it would be nice to here your feedback
chris

 

[xrk971]

Thank you, chermann,

I just switched to all Silmic II 10uF 35v for every cap and it sounds very nice. Listening to it on my reference speakers at present. No lack of highs or clarity.

 

[chermann]

fine......and then you should try the green caps at the rca...

 

[chermann]

Hi X
if you want a better focus at the speakers please try this:
as sandwich to avoid vibration - filter between your stand and your speaker
gel pads...e.g
https://www.amazon.de/gp/product/B00EANTICY/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

bamboo plate.e.g.
https://www.amazon.de/gp/product/B0015ZCSS6/ref=ppx_yo_dt_b_asin_title_o04_s01?ie=UTF8&psc=1
gel pads
speaker


chris

 

[Kay Pirinha]

Are you joking?
Best regards!

 

[chermann]

Are you joking?
Best regards!

No

 

[picowallspeaker]

I use to hang 'em on elastic bands...
BTW those naked amps look great

 

[chermann]

Hi

for me its logical to de coupling mechanically. a sub has a linear movement about 5-10mm a twetter much less -lets say 1mm max.
so every mechanical stress (vibrations) that comes from the sub driver interact with the twetter and with the stand wherer the speaker is mechanical coupled. the target is th let the mecahnicel swing(vibrations) let go away to a defined region - not to the chassis

if you think about a the mechanical decoupling in very good turntables then you understand me.

chris

 

[chips666]

https://www.amazon.de/Bostik-Blu-Ta...id=1569829342&sprefix=blu tack,aps,151&sr=8-3

https://www.amazon.de/Pritt-PGP55-M...ords=pritt+poster+buddy&qid=1569829492&sr=8-1

Pritt poster buddy and Blu Tack commonly used between speakers and stands
Enjoy...

 

[grandwazoo]

What I've done is to keep the amp muted all the time and only unmute via a raspberry pi GPIO when it starts playing music. If the power goes out the raspi goes out fast and the mute kicks in before the SMPS power ramps down and causes the pop.
Obviously, a dedicated controller that would watch the fault signal and trigger the reset would be better but that would be another project.

Can you (or anyone - it was a while ago!) point me to a schematic/piece of code for this?

 

[highcut28]

must say from post #898 onwards i am totally confused.
That 3255 looks nothing like mine which is the generic chinese one, also like the the ones pictured in the posts just before # 898 .

 

[Think]

You can find that board here: TPA3255 Reference Design Class D Amp GB

 

[highcut28]

You can find that board here: TPA3255 Reference Design Class D Amp GB

Ah i see Thanks

 

[chermann]

fake amp modifications

Hi


my TPA3255 - Fake amp" post 767.
https://www.diyaudio.com/forums/class-d/309813-wrong-tpa3255-77.html#post5701127
....was running about 5 month by my brothers big house. at this hot summer he was happy that he don´t fire up his F5 class A clone.
at some compare sessions i can say that my TPA3255 sound nice but the voices and vocals are not "stable", the board has the AD8599 and i claimed that this configuration is not so good as the AD1602 opamp. additionally the background noise was not as good as i remember - long term listening gets little bit boring. i thought the amp was better before i deliver this to my brother..



source:

i played around with the TPA3116 dual amp and in this thread i get the hint to use a 470nF + 10 R Zobel
https://www.diyaudio.com/forums/cla...pa3116-2-0-100w-dual-chip-12.html#post5876827
this push be to try it out on my TPA3255 - fake amp.


the zobel is like a big LPF for the complete amp.

i tried 220nF +10R (3W), 2x 220nF +10R (3W), 680n+10R (3W) at the speaker terminals.

immediately i realized that the 220nF+10R - small Zobel helps very much!


finally i found the 2x 220nF +10R as best solution. now its dead quiet and the amps sounds very realistic. the dynamic is very very nice.
680nF is too much - the 220NF is good but the annoying "ringing" is still here.


at the attached document you will find some measurements without filter (right) and the 3 different zobel networks.


the pics shows a contest where some DIY speaker (4" +1, partly active) guys made a session. at this event i moved my DAC (CM6631A + fake amp) with me. i know that they are not really interested in compare "electronics". so i enjoy and wait...late evening i was lucky to demonstrate my DAC+amp....
the small speakers on the table - "twiggy" (81db...) i have to push over 1 hour with a lot of titles... i get from all guys very positive feedback



chris

 

[Radian]

For all who have a differential dac and don't care about bleeding ear sound levels I ecourage you to just bypass
the whole input Stage. It's a worthwhile sonic improvement. There are four 100ohm resistors next to the opamps
where you can attache your leads.

Greets,
Klaus

 

[AnatoliyHill]

Hello, mates.Got my China's tpa3255 board with samwha cspacitors instead of Elna as it was promised. Sounds good. Much better than complete unit YJ i had before with Bluetooth onboard. This board delivering extra bass as i expected with my psu 48V/1200 w. It was only once i did it turnoff due protection circuit with very high volume on B&W 603. This board paired with b&w603 really make audible sence of biwiring. Even regular copper audiocable 2,5 sq.mm immediately extend highs being connected biwiring. Mistics in cables exists imho. Btw on one photo i used direct plugin DAC ES9082 to tpa3255 directly eliminating any cables. I tried to find rca connectors male- male rca but they are not available nearby, ordered via Ali express of course they anything even what seems stupid.

 

[sorokin]

Hi all

I am really sorry I did't read at all this topic, but could you please tell me or to sum up: buying tpa3255 board from Aliexpress is it a good idea? Whats wrong with them? Or in general it is good?

If not, recommend me please where to buy.
Thanks

 

[Alialiali]

Hi everyone,

I'm about to pull the trigger on 8 of these for an 8 zone house audio system:

Assembled TPA3255 DIY Digital Amplifier Board HIFI audio power AMP (300W + 300W) | eBay

Is it a crazy idea, and should I stick to cheaper boards? It's all cheap in honesty, because similar spec 16-channel amps will be much more expensive.

p.s. I have a separate matrix amp and volume controller for the 16 channels.

 

[Alastair E]

Anyone messed with these TPA3255 amps from Ali? They are built into an ally case, even come with a Vol knob! and have nice features inside like through hole coupling caps and socketed op-amps....

Input voltage, 24 to 48V, guess the low-voltage regulators are suitable for the higher voltages without mods...

cheap at 46 bucks, I've got one coming.....

AIYIMA TPA3255 Power Amplifier 300Wx2 Class D Stereo Audio Amp HiFi 2.0 Digital Amplifier For Speaker Home Sound Theater DIY on AliExpress