We see a lot of 2-channel TPA3255 based modules, but 4 channel ones are rarer. I bought this one off AliExpress for $50 including shipping - that's $12.50 per channel!
Build quality is OK but not great. The power and speaker I/O is all screw terminals, where better modules use spades. The capacitors are rated at 50V which is a bit tight - but then again the vendor does suggest a 36V supply. We'll see later that this is sensible as raising the power supply voltage to 42V doesn't do much to help performance. The heatsink is fine. There are no pins to expose the TPA3255 control and status signals, which is a bit annoying if trying to build a more sophisticated amp with soft-start, or clipping detection.
Does it do what a TPA3255 should do in terms of power and distortion? Yes it does
. It's wonderful to be able to get this level of performance so cheaply. Full details below...
The test rig is a Topping D10 Balanced, a 150W/4.7ohm dummy load, a DIY AES17-25 filter (https://github.com/mattclarkdotnet/aes17_filter_25), and a Cosmos ADC. Power was from my bench DC supply - I have some cheap AliExpress supplies to test later.
The TPA3255 Single Ended THD+N should be this (from the TI data sheet), so about 0.01% THD+N at 1W, and 60-70W available before distortion takes off:
Starting with frequency response it's as expected, just 1dB down at 20KHz
At 36V power performance is as expected, topping out at around 70W, with 0.01% THD+N at 1W
EDIT: my bench supply was the limiting factor, it actually does more like 85W at 0.1% THD:
Increasing the power supply to 42V gives pretty much the same result: EDIT - this is a limitation of my bench supply
The 1KHz FFT is very clean:
The 1/3 octave multitone less so, though I think I need to adjust my REW settings a bit:
And finally the 19/20KHz multitone is also good for the price:
Build quality is OK but not great. The power and speaker I/O is all screw terminals, where better modules use spades. The capacitors are rated at 50V which is a bit tight - but then again the vendor does suggest a 36V supply. We'll see later that this is sensible as raising the power supply voltage to 42V doesn't do much to help performance. The heatsink is fine. There are no pins to expose the TPA3255 control and status signals, which is a bit annoying if trying to build a more sophisticated amp with soft-start, or clipping detection.
Does it do what a TPA3255 should do in terms of power and distortion? Yes it does
. It's wonderful to be able to get this level of performance so cheaply. Full details below...The test rig is a Topping D10 Balanced, a 150W/4.7ohm dummy load, a DIY AES17-25 filter (https://github.com/mattclarkdotnet/aes17_filter_25), and a Cosmos ADC. Power was from my bench DC supply - I have some cheap AliExpress supplies to test later.
The TPA3255 Single Ended THD+N should be this (from the TI data sheet), so about 0.01% THD+N at 1W, and 60-70W available before distortion takes off:
Starting with frequency response it's as expected, just 1dB down at 20KHz
EDIT: my bench supply was the limiting factor, it actually does more like 85W at 0.1% THD:
Increasing the power supply to 42V gives pretty much the same result: EDIT - this is a limitation of my bench supply
The 1KHz FFT is very clean:
The 1/3 octave multitone less so, though I think I need to adjust my REW settings a bit:
And finally the 19/20KHz multitone is also good for the price:
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