Thanks, Chris!
The infos given at Anazon are somewhat poor, I'd say. So, how would one know the data? And is it plausible that this chip operates at split rails?
Best regards!
If it was my money, and I wanted a TPA3255 amp board, it'd be one of these:
TPA3255 2x260W 2Ch Class D Audio Amplifier | eBay
For class AB amplifiers you can use the delayed relay circuits but they are no good for class D amplifiers because the class D amplifiers should be loaded at the outputs all the time they are with power. The problem should be solved with the chip control pins.
Are this protection board any good
BTL TDA7498 TPA3116 TDA7492 Digital Amplifier Speaker Protection Board Module | eBay
BTL TDA7498 TPA3116 TDA7492 Digital Amplifier Speaker Protection Board Module | eBay
I think the discussion on this page would be helpful to answer your question.
TPA3255EVM to complete amp (advise needed)
Regards,
It seems like a traditional relay board.
It is claimed to be a speaker protection board and as such it probably protects the speakers. The problem is that a class D amplifier should never be powered without a load. A traditional relay board disconnects the speakers at start-up and that may damage the class D amplifier.
So, while the speakers are protected the amplifier may be damaged. Therefore I will conclude no-good.
Hi, mates. Seems like my unit is finished today. The sound reptoduction was interrupted during listening, now deadly silent. Red light is on. No smell, no visible damage of the board. Any idea how to restart it? May be some safety option were activated like temp/ voltage etc? As an reason I believe might be switching speaker s on the go, thus for deconds amp was been on without load. I forgot D amps djould be loaded all the time.
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Restart: Power OFF for some minutes and then power back ON.
Before restart do the following test without power and without connection to speakers and input source: With an Ohm-meter, check the impedance of all four output lines toward the ground rail, toward the supply rail and from one output line to the other. Any combination measuring below 100 Ohm?
I have one of those BTL protection boards. The relays are only rated for 3 amps. It is definitely for bridged amplifiers like tpa3116 and tpa3255 in bridged mode. I decided not to use it on my tpa3255 board because of the very low relay rating. It might be ok for a stereo tpa3116 board.
If you are worried about a chip failing and damaging your speakers put 2 10,000uf capacitors connected + - - + in series with your speaker. If the chip fails and dumps the dc rails on your speaker, you will get a thump sound while the cap charges up. Your speakers should be fine. Many old solid state amplifiers that had a single rail supply cap coupled the speaker to the output stage. The tpa3255 does the exact same thing when run in SE mode.
If you are worried about a chip failing and damaging your speakers put 2 10,000uf capacitors connected + - - + in series with your speaker. If the chip fails and dumps the dc rails on your speaker, you will get a thump sound while the cap charges up. Your speakers should be fine. Many old solid state amplifiers that had a single rail supply cap coupled the speaker to the output stage. The tpa3255 does the exact same thing when run in SE mode.
Hello,
Did someone identified suitable heatsinks for DIY TPA3251 and TPA3255 boards ? The reference used on the TI EVM boards does not seems to be a common off the shelf model.
And sometimes those heatsinks are a significant par of the final price...
Help on this side would be welcomed,
Best regards,
JMF
Did someone identified suitable heatsinks for DIY TPA3251 and TPA3255 boards ? The reference used on the TI EVM boards does not seems to be a common off the shelf model.
And sometimes those heatsinks are a significant par of the final price...
Help on this side would be welcomed,
Best regards,
JMF
I've got a 3e audio TPA3255 board with a Meanwell LRS-350-48.
It sounds great but is ridiculous massive overkill for my desktop PC setup.
I do hear a faint click through the speakers when I turn the amp on, but nothing to worry about IMO.
I just measured it and the whole setup is using 10.8W from the power point while idle, with just the tpa3255 using 0.134A @ 48V = 6.432W when idle (and virtually the same at any volume level that I'd ever use, which I found interesting).
Does this seem like too much? The TPA3255 datasheet says it should be less than 2.5W, the rest of the 3e audio board shouldn't be using 4W while idle, I wouldn't have thought.
How many watts are other people with the 3e audio TPA3255 board measuring when idle?
It sounds great but is ridiculous massive overkill for my desktop PC setup.
I do hear a faint click through the speakers when I turn the amp on, but nothing to worry about IMO.
I just measured it and the whole setup is using 10.8W from the power point while idle, with just the tpa3255 using 0.134A @ 48V = 6.432W when idle (and virtually the same at any volume level that I'd ever use, which I found interesting).
Does this seem like too much? The TPA3255 datasheet says it should be less than 2.5W, the rest of the 3e audio board shouldn't be using 4W while idle, I wouldn't have thought.
How many watts are other people with the 3e audio TPA3255 board measuring when idle?
Have you tried putting the amp in reset mode (ground the reset pin) and see if the consumption changes?
I had an SMSL SA-S21 which is a TA2021B before, and it was (just) loud enough but didn't have any extra headroom so I suspected there was extra distortion. The TPA3255 was only slightly more money than TPA3251 so I just got that. I could definitely have gotten away with a much smaller PSU.
I wanted to hear what 0.01% THD sounds like, and it does definitely sound better, but I must say I was surprised that the whole setup is using almost 11W all the time now.
Haven't tried that yet but I will later on. I forgot to mention that the amp heatsink is warm all the time, not hot but warm.
I have the 3251 from 3e but haven't measured it. The 2.5W mentioned in the datasheet is idle loss for the chip itself and there is a note mentioning that output inductors can increase that. There also is another dc-dc converter that's always on on-board for the 12v supply and input buffers, and the buffers probably have some power consumption as well.
And then, based on how quiet your pre-amp/dac is the amp is probably never idle so the reset switch plus lower voltage power supply or even a relay driven by your pre-amp/dac would help a lot.
And then, based on how quiet your pre-amp/dac is the amp is probably never idle so the reset switch plus lower voltage power supply or even a relay driven by your pre-amp/dac would help a lot.