I was not aware about the difference and ordered this board at cheapest price available. Though the list was for blue board but I received a black board
Have you tested it?
Does it have pop sound when power up and shutdown?
Does it sound good?
PFFB -- If you can get away with the lower gain, the idle noise will decrease accordingly. If you have to turn up the gain elsewhere to make up for the PFFB, you're basically back to square one.
* I'd think this would matter only in the most extreme of sensitive speakers and/or ground loops. The former would be important for sound reinforcement (who needs this many watts PLUS super sensitive speakers for domestic hifi?!) and the latter should be addressed, not blamed on the amp itself.
* I'd think this would matter only in the most extreme of sensitive speakers and/or ground loops. The former would be important for sound reinforcement (who needs this many watts PLUS super sensitive speakers for domestic hifi?!) and the latter should be addressed, not blamed on the amp itself.
no, that is not the hole truth. Idle noise can be reduced due to the fact that input referred noise of TPA3255 is something like
65uV/Gain = 6.5uV.(rms)
There are lots of OPAs with significant lower input noise.
Following this, you can reduce gain of TPA3255, compensate gain loss with a preceeding OPA and achieve a lower output noise at the same total gain.
In my private test setup I did demonstrate this achievement.
65uV/Gain = 6.5uV.(rms)
There are lots of OPAs with significant lower input noise.
Following this, you can reduce gain of TPA3255, compensate gain loss with a preceeding OPA and achieve a lower output noise at the same total gain.
In my private test setup I did demonstrate this achievement.
Of course, Voltwide, I guess I should have provided the caveat that an inverting, 10k input impedance NE5532 (like the EVM but changing the feedback resistor) will have higher noise than the internal gain structure of the TPA3255, albeit marginally. Plenty of ways to go lower both on input impedance or switch over to something like an OPA164x (suggested due to DI process lowering CM distortion and jfet-input) and have a very high input impedance non-inverting topology. A direct swap from the NE5532 on the EVM to a OPA2209 would also lower the noise appreciably.
I couldn't find any additional information about it, but in the pictures it looks like there is no earth ground (marked "NC", not connected, on the board), which means you could use it with a 2-prong power cord, but might need to be careful about grounding of input devices for your amp or you could have noise. Typical RCA outputs/inputs are earth-grounded but it depends on the source.
Also, it does not appear to be adjustable, which I guess means you get 48V and only 48V? For tpa3255, I like to run at 51V. And there's no PFC mentioned.
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The TPA3255 cheap Amp. board from china is not capable of delivering high power under 4 Ohm load.
(keyword : Classe D TPA3255 MINI HIFI 300 W + 300 W)
I bought 2 TPA3255 board last week and test it under different conditions. it seems the chip can be easily overheated and shut down itself under 4 ohm load. The heatsink is not hot when running, howevery, it always shutdown when i try to deliver high power into speaker.
i can not make it delivery more than total 150W power into a pair of 4 Ohm speaker even under "cooler" situation (reduced supply voltage to Vin = 36V.)
the others TI's prodect, TAS5630, is founded have similar thermal issues on another china amp. board. but the thermal problem is not that serious comparing to cheap TPA3255 board.
(Keyword : YJHIFI TAS5630 Classe D 2*300 W)
I am quite sure about it's all about thermal issue because the self shutdown problem is reduced when I add a fan on the top of heatsink.
Anyone have similar experience with TPA3255 ?
(keyword : Classe D TPA3255 MINI HIFI 300 W + 300 W)
I bought 2 TPA3255 board last week and test it under different conditions. it seems the chip can be easily overheated and shut down itself under 4 ohm load. The heatsink is not hot when running, howevery, it always shutdown when i try to deliver high power into speaker.
i can not make it delivery more than total 150W power into a pair of 4 Ohm speaker even under "cooler" situation (reduced supply voltage to Vin = 36V.)
the others TI's prodect, TAS5630, is founded have similar thermal issues on another china amp. board. but the thermal problem is not that serious comparing to cheap TPA3255 board.
(Keyword : YJHIFI TAS5630 Classe D 2*300 W)
I am quite sure about it's all about thermal issue because the self shutdown problem is reduced when I add a fan on the top of heatsink.
Anyone have similar experience with TPA3255 ?
I use the black version.
just solved my TPA3255 China cheap amp thermal issue by inserting a small piece of aluminum between TPA3255 chip and heatsink.
no shutdown observed anymore.
it seems the thermal design of that TPA3255 cheap amp board should be improved a lot or it will never deliver high power into speaker.
happy now !
google drive photos
IMG_5297.JPG - Google Drive
IMG_5296.JPG - Google Drive
just solved my TPA3255 China cheap amp thermal issue by inserting a small piece of aluminum between TPA3255 chip and heatsink.
no shutdown observed anymore.
it seems the thermal design of that TPA3255 cheap amp board should be improved a lot or it will never deliver high power into speaker.
happy now !
google drive photos
IMG_5297.JPG - Google Drive
IMG_5296.JPG - Google Drive
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It's not a problem of the board but the heat sink and it's thermal connection to the chips top power pad. The interface should be made of polished surface at the heat sinks side with a thin layer of thermal compound. Best results are archived with removed eloxal and mirror polished surface.
Just wondering if those power adapter used for POE networking can be used? It looks like those laptop adapter.
Power rating is 48v 3amp (144w).
No that's not a good idea. You should bring them 400W - 600w from a good qualty smps like one from connex Electronic like this.
SMPS600RS | Connex Electronic
Power rating is 48v 3amp (144w).
No that's not a good idea. You should bring them 400W - 600w from a good qualty smps like one from connex Electronic like this.
SMPS600RS | Connex Electronic
It depends... how these power adaptors behave near the current limit. Does the voltage sag, is there a shutdown on current limit, etc.
TPA3255 can deliver 150W each channel in 8 ohms. With moderate sensitive speakers average power drain should stay at about 10-20 watt and peaks a bit higher. If you promise not to exceed normal listening levels at home, there is no need for those ridiculous large power supply's.
If you have such a power adapter available, give it at try. Don't buy a new one, in that case its better to buy a Meanwell.
TPA3255 can deliver 150W each channel in 8 ohms. With moderate sensitive speakers average power drain should stay at about 10-20 watt and peaks a bit higher. If you promise not to exceed normal listening levels at home
, there is no need for those ridiculous large power supply's.If you have such a power adapter available, give it at try. Don't buy a new one, in that case its better to buy a Meanwell.