TPA3255 - all about DIY, Discussion, Design etc

Founder of XSA-Labs
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Final thing to check is the bootstrap capacitors. If incorrect value or too low of a voltage here, it is a problem. I have seen bad bootstrap caps causing low power output and instabilities. One time the caps exploded. Rating may have been non compliant or a mistake in values at the factory. Just remove them and install known good quality ones from Panasonic or TDK etc.

Beyond that, you may have a bad TPA3255 chip. $11 for a new one. Fairly easy to swap with hot air workstation.

By now, might have been better to spend $100 on a higher quality amp board. :)
 
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I'll remove the bootstrap caps and replace them with some proper 220nF ones I have around. I'm honestly tired of this amplifier, while it works at "normal" volume rates, I'd like to be able to push it to certain sound levels as well.

Besides, your idea of buying something better actually does make sense. In the future I'm going to package both this amp and an headphone one into a single case, might be worthy getting something proper.
 
Founder of XSA-Labs
Joined 2012
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The TI EVM board recommends 0.033uF 25V X7R for bootstraps. You might want I upgrade to 50v rating. Where did you see 220nF?

https://www.ti.com/lit/ug/slou441/slou441.pdf


IMG_9836.jpeg
 
I'm aware they suggest 33nF. I found something on TI's forums on a discussion with issues similar to mine, which then points to a SLOA for bootstrap crcuits for TPA31xx devices, which as far as I can see are pretty similar to the 32xx.

https://e2e.ti.com/support/audio-group/audio/f/audio-forum/1196004/tpa3255-fault-shutdown
https://www.ti.com.cn/cn/lit/pdf/sloa259?keyMatch=SLOA259

What they are saying, if the bootstrap capacitor hasn't got a large enough value, the output mosfets in certain conditions could not turn on fully inducing a large Vds voltage and tehrefore a "fake" overcurrent situation (as load current is measured on the drain-source votlage with a 'known' RdsON).

I'll keep you posted once I get some results!
 
@tschrama
ohh so sadd.. maybe get defective/bad product.. which one your Amp??
i will buy from Aliexpress too.. Basic Price + Shipping + Tax to my Country maybe became expensive (im predicted 2xBasic Price)
so i'll selective with minimalist broken..

*only ZK-3002 available on local online shop, but price around $35
 
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I have a variation of 2023 Upgraded version TPA3255. This type of design uses series connected 25V power decoupling Caps. So the ESR will be double and capacitance will be half. It may be low impedance load application will not fit. But it keeps working so far ...
oke.. thankz..
are U recomended this type vs other??
btw i'm also following u'r tutorial at Cyberpithilo modifying XH-M543 TPA3116D2 , but failed😂
 
@zintolo
at local online shop Aiyima brand hard to find here, mostly Fosi Audio..
my goverment also blocking import from Aliexpress since October 2023..
now more difficult self import from Aliexpress since blocked.. if using 3rd Services import from Aliexpress, total price became nearly twice😩
so, im carefully choosing what TPA3225 model which i buy😆
 
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@robbayani

are U recomended this type vs other??

Well, it still works but I don't recommend 2023 Upgraded version TPA3255 not so much. Especially using this board with a 48V supply. (30V - 35V will be better)
  1. Needed to add the automatic RESET driver for the anti-pop. (Power-on pops may damage the sensitive speakers)
  2. Too small a heatsink (Thermal shutdown will occur if you drive maximum power with 48V supply)
So my recommendation is ZK-3002 from a low-cost point of view or 3e-audio PFFB from the specific performances.
 
@tschrama
ohh so sadd.. maybe get defective/bad product.. which one your Amp??
i will buy from Aliexpress too.. Basic Price + Shipping + Tax to my Country maybe became expensive (im predicted 2xBasic Price)
so i'll selective with minimalist broken..

*only ZK-3002 available on local online shop, but price around $35
ZK-3002 is failed product, you have to make capacitor mod to make them works right and no guarantee that it would make them last. I have 2 tpa3255 (aiyima A07, fosi M03) and they are good enouh for my home theatre. So if you not like mod your amp i suggest a aiyima/fosi or anything that have a good brand (my fosi is include with the 32v adaptor!), it's guarantee to works well from the start, no pop up issue, including the amp box, sure its more costy but you always have peace of mind that its works well
 
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@robbayani



Well, it still works but I don't recommend 2023 Upgraded version TPA3255 not so much. Especially using this board with a 48V supply. (30V - 35V will be better)
  1. Needed to add the automatic RESET driver for the anti-pop. (Power-on pops may damage the sensitive speakers)
  2. Too small a heatsink (Thermal shutdown will occur if you drive maximum power with 48V supply)
So my recommendation is ZK-3002 from a low-cost point of view or 3e-audio PFFB from the specific performances.
okee.. maybe i choose this.. this is risk for cheap Amp..
can i use anti-pop schematic what u build??
i see u make antipop schematic for 3255 on several page backward.. the board likes similar..

@lokonsky
thankz for the info.. Aiyima/Fosi price 2-3x than " Cheap Chinese board TPA3255 from Aliexpress"..
i'm just want to "try" TPA3255 for first time, so ill will search cheap as possible.. sorry for that
 
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The most different point is the capacitors for the re-construction filter. Non-PFFB amps are simply related to the reconstruction filter's performance.
BDM8 uses MLCC, on the other hand, BDM9 uses Film Caps. MLCC's capacitance will decrease when the large voltage swings. So the large swing distortion spec value might be a little bit different but hard to say whether you can hear those differences.
I guess the BT Audio chip's sound quality will be much more related to its quality than the difference in caps.