TPA3255 - all about DIY, Discussion, Design etc

Amigos...

I have the feeling that Aiyima still has not kept his promises.... Another TPA3255, with bad caps....

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AIYIMA TPA3255 Bluetooth 5.0 Digital Power Amplifier 315Wx2 Audio Speaker Amplifier Class D Sound Amplificador PCM5102 Decoding| | - AliExpress
 
I too power 3255 2 channel with big old 525va 35v trafo and a load of capacitance. I leave it powered 24/7 and prefer the simplicity and reliability of this set up over SMPS.

I have seen well made SMPS fail and luckily the safety systems kept things in check....ie kept your house from burning down .
I do not know enough to tell a good SMPS/LLC psu from a bad one, so I keep clear.
YMMV of Course!
 
This is my psu, it says it is ultra low ripple, 400w 8.3A. It is adjustable +-10%. I don’t have any way to measure it in any way. I have been impressed with it, my amp is silent with my ear to the speakers.

I have the same one but in 36V version.
The ripple is low but not ultra low compared to the Connex SMPS PSUs.
Anyway, it works pretty fine and voltage is stable and ajustable indeed, good point )
Conversion efficiency is about 93%.

Would be nice to have DrMordor's opinion about the LLC PSUs for Audiophile usage. I know he is a defender of LLC technology ))

Almost sure Cdsgames could answer to this ? Can you share your opinion too ?
 
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Get a meanwell SMPS, it has a decent performance. Get the SE-450-48 or LRS-350-36

I also have an adjustable generic SMPS, it is now blown up (when I started it at 51VDC with load), I'm ordering some parts for it. Its main mosfets looks 2nd hand and has different part numbers, also the mains caps look second hand. Don't buy them!.

Here's the scope comparison of Meanwell LRS-350-36 vs SMPS300RS (I also own both).

They have the same ripple, except that the meanwell has a higher switching noise (65kHz) (192mV-pp).

Noise of Connex is only slightly higher than its ripple.

Meanwell also produces clean noisefloor on my TPA3255 THD measurements. Unlike my generic adjustable SMPS which has some spurious noise in 22kHz.
 

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  • SMPS300RS.jpg
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Get a meanwell SMPS, it has a decent performance. Get the SE-450-48 or LRS-350-36

I also have an adjustable generic SMPS, it is now blown up (when I started it at 51VDC with load), I'm ordering some parts for it. Its main mosfets looks 2nd hand and has different part numbers, also the mains caps look second hand. Don't buy them!.

Here's the scope comparison of Meanwell LRS-350-36 vs SMPS300RS (I also own both).

They have the same ripple, except that the meanwell has a higher switching noise (65kHz) (192mV-pp).

Noise of Connex is only slightly higher than its ripple.

Meanwell also produces clean noisefloor on my TPA3255 THD measurements. Unlike my generic adjustable SMPS which has some spurious noise in 22kHz.

Hello
An improvement with a loop of wires between smps and amp in a Clamp filters like https://product.tdk.com/info/en/catalog/datasheets/clamp-filter_commercial_zcat_en.pdf.
Self between 10 to 20uH.
Test done with ZCAT2032-0930.
Best regards
Roger
 
Have you tried this for LRS-350-36 or for the connex?

If we can lower down the switching spikes from LRS-350-36, it will be a winner in price/performance.

I'm getting slightly lower THD when I use connex SMPS300RS. but the price is triple, not worth the added price I think.

Hello
An improvement with a loop of wires between smps and amp in a Clamp filters like https://product.tdk.com/info/en/catalog/datasheets/clamp-filter_commercial_zcat_en.pdf.
Self between 10 to 20uH.
Test done with ZCAT2032-0930.
Best regards
Roger
 
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Hello
An improvement with a loop of wires between smps and amp in a Clamp filters like https://product.tdk.com/info/en/catalog/datasheets/clamp-filter_commercial_zcat_en.pdf.
Self between 10 to 20uH.
Test done with ZCAT2032-0930.
Best regards
Roger

This is a ferrite clamp right ?
As you can see on my amps, I am always using some Ferrite clamps.
I shared a few pages back that the Cook Book from New Class D, highlights that ferrites are very useful when properly positioned (anti RFI / EMI)
 
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SINAD - Wikipedia

It's an easy way to compare different pieces of equipment, but ultimately is not very meaningful in and of itself. For example - any amount of noise will affect SINAD, but the threshold of audible noise depends on the sensitivity of your speakers. THD similarly will affect SINAD, but we know that very large amounts of H2 (perhaps 5-10%) and H3 (perhaps 1-10%) are inaudible while higher orders may be very audible, so the distribution of the various orders is important too.
 
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