Why then did you wrote an email to the vendor of that particular board? If you aren't interested in a solution you don't need to do any measurements at all.
(Maybe it's just a picture polarity issue)
Vendor says to try it with a smps psu...
And yes I hope to find a solution for that problem...but showing the measurements to all here will not be the answer...schematic would be a better place to look for eventual cause...
So far there is only a lot of questions over here (thats ok) but I was hoping to find some users here with the same board...
Anyway, I will stop discussing issues and live with the equalisation as a solution for my problem or use one of many other amps and enjoy some music...
I will come back with the results of the smps and the other tpa3255 board...
Other users of tpa3255 are off course most welcome to share their findings...
Any chance you have the polarity swapped on the one of the speaker wires?
I made this mistake with a cheap tpa311x amp a year or two ago; I thought the amp had some serious issue, but it was good old operator error. (Though I think there was at least one cheap tpa311x board that had the speaker polarity mis-labeled on one channel.)
It's a very unusual sound when one channel is exactly out of phase with the other, but IIRC, lack of bass is the most prominent characteristic. (This makes intuitive sense to me, as with a lot of recorded music, bass typically isn't panned to one side, so if you play each speaker out of phase, much of the bass will cancel. Based on this, another easy test is to find some music where the bass is panned to one channel, and see if the problem persists. I haven't looked at this in a while, but I believe a lot of the Ramones recordings have bass mostly on only one channel; I think some of the Beatles recordings are like this too.)
Also, is your source single-ended or balanced? On the 3e-audio tpa315x boards, there is a jumper for each input where you select single-ended or balanced input. If you haven't already, double-check that both jumpers are set correctly, and also that the wiring is correct.
Please don't take my simple suggestions as patronizing... Almost all the issues I've personally dealt with tend to be silly things I overlooked, so sometimes it helps to go back to the basics and do simple sanity checks.
I made this mistake with a cheap tpa311x amp a year or two ago; I thought the amp had some serious issue, but it was good old operator error. (Though I think there was at least one cheap tpa311x board that had the speaker polarity mis-labeled on one channel.)
It's a very unusual sound when one channel is exactly out of phase with the other, but IIRC, lack of bass is the most prominent characteristic. (This makes intuitive sense to me, as with a lot of recorded music, bass typically isn't panned to one side, so if you play each speaker out of phase, much of the bass will cancel. Based on this, another easy test is to find some music where the bass is panned to one channel, and see if the problem persists. I haven't looked at this in a while, but I believe a lot of the Ramones recordings have bass mostly on only one channel; I think some of the Beatles recordings are like this too.)
Also, is your source single-ended or balanced? On the 3e-audio tpa315x boards, there is a jumper for each input where you select single-ended or balanced input. If you haven't already, double-check that both jumpers are set correctly, and also that the wiring is correct.
Please don't take my simple suggestions as patronizing... Almost all the issues I've personally dealt with tend to be silly things I overlooked, so sometimes it helps to go back to the basics and do simple sanity checks.
You made me doubt...thought I forgot one jumper to set on SE...but it is not...
Speakers are in phase...double checked it again with test file...
Anyway, glad you would share some possible causes...thanks!
I will wait for the smps psu and see from there...also another TPA3255 board on order...meanwhile correct the problem with the equalizer...
Thanks!
Speakers are in phase...double checked it again with test file...
Anyway, glad you would share some possible causes...thanks!
I will wait for the smps psu and see from there...also another TPA3255 board on order...meanwhile correct the problem with the equalizer...
Thanks!
Yep, tried about everything out there...all sound fine, no complaints...
runeaudio, volumio, daphile, hqplayer, roon, jriver, ap linux...
Amazing wat a simple RPI3 with rune or volumio can do...
If sombody ask me what to pick for a small budget, I would say RPI3 with runeaudio or volumio...and a decent usb dac...
If the budget is no problem I would choose intel nuc with ROON ROCK...
( that is what I am using)...
Love this hobby...
I finally got my trafo delivered. It's a 0-15-18-25VDC single secondary 250VA trafo. The VA is high as compared to the needs of 3116d2. I have connected the 15v tap to a linear unregulated PSU and it's feeding the 3116 board.
What a difference did it make to the sound !!
... the sound cleaned up,
... it more musical now,
... bass is much better (maybe bcos of rock steady psu & 18000 mfd; my earlier psu was smps 24v 10A)
... since there is no switching noise being fed to the line, sound clarity is higher..
In short, the improvement is huge, and I dare say I have to hear a good Class A to get convinced that those power hungry and hot monsters are better.
What a difference did it make to the sound !!
... the sound cleaned up,
... it more musical now,
... bass is much better (maybe bcos of rock steady psu & 18000 mfd; my earlier psu was smps 24v 10A)
... since there is no switching noise being fed to the line, sound clarity is higher..
In short, the improvement is huge, and I dare say I have to hear a good Class A to get convinced that those power hungry and hot monsters are better.
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"Musical" is the same as "sweeter" that many forum members use.
Bass "much better" is that the lower freq bass notes are much clearer, and bass is 'fuller'.
There are so many 3116d2 boards that results after mods can vary. On my board, the improvement has been clearly audible.
So, other's who use 3116 can try out lpsu and see for themselves.
Bass "much better" is that the lower freq bass notes are much clearer, and bass is 'fuller'.
There are so many 3116d2 boards that results after mods can vary. On my board, the improvement has been clearly audible.
So, other's who use 3116 can try out lpsu and see for themselves.
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Upgrading from 36V -> 48V may give a bit more "precision/attack" to the lower frequencies but wont change the frequency response at all. This also would only apply if your power-supply is hard dropping at high output levels. If the clip-led never came on while testing, this isn't related.
Have you measured the audio bandwidth of the amp?
Nice death-trap-. Why not spending some more bucks into a MeanWell supply for additional safety?
he don't need to we had done the test before we ship out.
the reason why i suggested switch to 48V is that,with 36V power supply at 8ohm speaker,he can only get around 75W~90W output.
i sent some measurement to him and hope he can do comparing on that.
Found the problem...
I have a digital bass processer with equalising settings for 30, 60 and 90 hz, just double checked these settings and the 90 Hz setting had -4 db less then the other two...now they are all the same level and no further equalizing is needed in Roon...
Strange all my other amplifiers did not mind this...
tpa3255 from 3e-audio is now playing beautifull...I guess that is what HD stands for... 
Douk is also on the TPA3255 now. Cheaper, terminals seem ok, any opinions on the layout?
TPA3255 Digital Power Amplifier Class D Audio Amp Assembled Board 300W+300W HiFi
They boast Elna caps rated at 3900uF at 100v, but that's about it. The rest seems "good enough" to me, but other than that nothing to rave about but the price.
Summary of their Boast list:
1. using original TPA3255 (Hahah! they just had to put it in writing.)
2. main filter electrolytic capacitors using ELNA brand, capacity 3900UF / 100V * 2, to ensure a strong stream of continuous power support.
3. resistance selection of high precision chip resistors, to ensure a good signal to noise ratio.
4. use of audio special inductance, to ensure sound crisp and powerful.
5. NPCB with 1.6mm thick double-sided sheet, 2.0 oz thick copper, tin spray the whole process to ensure the size of the current through the performance. First-class PCB quality.
TPA3255 Digital Power Amplifier Class D Audio Amp Assembled Board 300W+300W HiFi
They boast Elna caps rated at 3900uF at 100v, but that's about it. The rest seems "good enough" to me, but other than that nothing to rave about but the price.
Summary of their Boast list:
1. using original TPA3255 (Hahah! they just had to put it in writing.)
2. main filter electrolytic capacitors using ELNA brand, capacity 3900UF / 100V * 2, to ensure a strong stream of continuous power support.
3. resistance selection of high precision chip resistors, to ensure a good signal to noise ratio.
4. use of audio special inductance, to ensure sound crisp and powerful.
5. NPCB with 1.6mm thick double-sided sheet, 2.0 oz thick copper, tin spray the whole process to ensure the size of the current through the performance. First-class PCB quality.
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It seems to be the same, as already linked to. I think a member have picked one up, but not tested it yet
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Post 206
TPA3255 - all about DIY, Discussion, Design etc.
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Post 206
TPA3255 - all about DIY, Discussion, Design etc.