Sure Electronics AA-AB32313 2x400

How would you wire +- together?

I connected the speaker wires to the amp, and wondered why there was no sound when I noticed the cables were not connected to the speakers(I have two sets of amps and forgot that I plugged the other one in) :D

Then when I turned off to connect to the speakers I noticed on one of the channels, the cable had wired it self together at the other end making a +- loop. No magic smoke, no strange sounds or anything but it was maybe full power with music in a loop for 10 seconds.

I had no chance to listen to it before this happened so don't know if it did take any damage. But maybe it would have just either died or not taken any damage at all
 
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Well, the IC should handle that. :D

The STA516BE has build in overcurrent-protection.

Okay, it doesn't sound "wrong" as in damaged, distorted, or such. I hope I can conclude that it's damaged.

I think I notice somewhat lower signal on one channel, and overall definately(to my ears) worse sound compared to my TDA7498, less bass and treble, strange rugged midrangey sound.
 
Ali supplier, Power supplies and second revision

Cantunes: The board look original, even to small levels on the silkscreen, so I would say that they are good. It seems that there is a rev2 of the AB32313, so make sure that you are getting the new one.

strongbow60: Looks like yours is the new revision/
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clawmd: i have the AA-AB3151 1x500W version of the board and I am tunning mine with a minidsp and HLG-150H-36 set at 40V. I run tests with a bigger power supply and with test tones at 1000Hz at the fill .9 Volt output of the minidsp, the amp was consuming about 3 Amps. , so that power supply was enough. If you want an open frame look in CNC supply shops for 48 Volts power supplies.

I decided to use two of the the AA-AB3151 1x500w modules and two of the HLG-150H-36 to create a dual monoblock system. If you run the numbers, you can see that costwise is basically the same price as the AB32313.
 
The board I bought has physically bigger/better coils and might handle bigger currents before distortion levels rise. Make sure the you bypass the input capacitors as explained in the start of this thread. Even then it needs at least 100 hours playing before the sound opens up.

Also, the German seller has an optional heatsink that almost fits the board :) It is a big deal because the fan get annoying in the long run if not in a well sound proofed enclosure. Even when no input signal the fan turns on every ten minutes or so.

I also have the TPA3255 board and they are different sound wise.

The Wondon board has a more dynamic sound, fantastic bass, a warm midrange (2:nd harmonic distortion?) but a frizzy and not too pleasant treble. Perfect party board, but after a few hours you get listening fatigue (often attributed to high 3:d harmonic distortion).

TPA3255 eval board has not many faults, maybe a little "bland", nothing stands out. But in the long run much easier to listen to. Perfect to combine with a tube amplifier if you are of that persuasion.
 

ICG

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The board I bought has physically bigger/better coils and might handle bigger currents before distortion levels rise. [...]

Bigger is not always better. And the size does not say anything about the quality or at which point the core becomes saturated.

The Wondon board has a more dynamic sound, fantastic bass, a warm midrange (2:nd harmonic distortion?) but a frizzy and not too pleasant treble. Perfect party board, but after a few hours you get listening fatigue (often attributed to high 3:d harmonic distortion).

Well, I would attribute that to the coils. Besides that, your speakers might have a high impedance in the treble, which - like on all class D amps - causes a peak at the upper end. Your TPA3255 board got the output filter probably optimized for higher impedances which makes it probably flat or even dip in the hights, which could lead to the 'bland' impression. That is an assumption ofcourse, there could also other issues be involved too.

It looks pretty much like this:

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


Again: That's an issue with all Class-D amplifiers, not just these two. It just differs on to which impedance the output filter is optimized, the impedance these curves represent might be lower or higher, the tendency is always the same though, higher impedances create a peak, lower ones a dip. In general, the impedance of the speaker in the treble influences the frequency response of class D amps very much and changes the sound far more than most ppl anticipate. That also means that the sound impression in the highs can vary very much with different speakers.