Which TPA3255 amp do you recommend?

[aon500]

brezza BRZHIFI TPA3255-A
In your opinion is it better than AIYIMA A07?
Already the power supply inside, I don't know what kind of power supply it mounts.
Have any of you already tried it?
Does it make pop noise when it turns on and off?
Can you tell me something?
I'd be interested.

https://it.aliexpress.com/item/4000970577819.html?spm=a2g0o.detail.1000014.1.49061424Dp7UCQ&gps-id=pcDetailBottomMoreOtherSeller&scm=1007.14976.188500.0&scm_id=1007.14976.188500.0&scm-url=1007.14976.188500.0&pvid=376329a2-893f-472d-9137-8f0c9c8d79ba&_t=gps-idcDetailBottomMoreOtherSeller,scm-url:1007.14976.188500.0,pvid:376329a2-893f-472d-9137-8f0c9c8d79ba,tpp_buckets:668#0#131923#76_668#808#4094#456_668#888#3325#19_4976#0#188500#0_4976#2711#7538#635_4976#3104#9653#10_4976#3141#9888#10_668#2846#8113#622_668#2717#7561#397_668#1000022185#1000066059#0_668#3422#15392#316_4452#0#184418#0_4452#3474#16498#935_4452#3098#9599#585_4452#3564#16062#582

From DIY


https://www.diyaudio.com/forums/cla...iy-discussion-design-etc-216.html#post6221962

 

[Bruce Morgen]

From DIY


https://www.diyaudio.com/forums/cla...iy-discussion-design-etc-216.html#post6221962

These are now available in black -- and with North American voltage capability -- via eBay for $91USD.

"300Wx2 TPA3255 Bluetooth 5.0 DAC HiFi Home Power Amp with Tone Control Preamp Assembled Black"

 

[robertospeed]

I changed the OPA chips of my AIYIMA A07, put the OPA2604AP and the sound improved a lot, before the sound was inaudible and annoying and my ears hurt.
The NE5532 chips That mounts as standard, the sound is very dirty.

 

[Ralferator]

I changed the OPA chips of my AIYIMA A07, put the OPA2604AP and the sound improved a lot, before the sound was inaudible and annoying and my ears hurt.
The NE5532 chips That mounts as standard, the sound is very dirty.

That's crazy! I didn't expect such a huge difference. Some people seem to be very satisfied with the AIYIMA A07 with the standard OP amps, so this is really surprising.

 

[robertospeed]

That's crazy! I didn't expect such a huge difference. Some people seem to be very satisfied with the AIYIMA A07 with the standard OP amps, so this is really surprising.

try to change the OPA chips and then you tell me, they are so cheap and trying is cheap

 

[Ralferator]

try to change the OPA chips and then you tell me, they are so cheap and trying is cheap

Where can i buy those chips and be sure they are originals? And how to change? Just pull out with pliers and press the new ones in with my fingers?

 

[robertospeed]

Where can i buy those chips and be sure they are originals? And how to change? Just pull out with pliers and press the new ones in with my fingers?

Yes, you pull them with your hands or with suitable pliers and put them back in with your hands, I don't know if the chips I took are original, but they sound much better than the stock ones.
I got these on ebay : https://www.ebay.it/itm/IC-Circuito-Integrato-OPA2604AP-DIP-8-Lotto-2-Pezzi/184454650259?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160908105057&meid=17317c5807e445a487f060eb159b7315&pid=100675&rk=3&rkt=15&mehot=none&sd=254196861466&itm=184454650259&pmt=0&noa=1&pg=2380057&brand=-+Senza+marca/Generico+-&_trksid=p2380057.c100675.m4236&_trkparms=pageci:9ab1136f-0028-11eb-9387-0a1a1040332b|parentrq:cbbd024a1740a4d6b13da042fffea036|iid:1

Then there are also these on Aliexpress which I believe are ceramic originals: https://it.aliexpress.com/item/4001020269706.html?spm=a2g0s.9042311.0.0.3f814c4dhmfd8u

Then I'd like to try these too: OPA21O7AP

 

[startkapital]

I might have to upgrade to the EAUMT-0260-2 B Version to cycle trough OP amps myself

Is there a comprenhensive list for available Opamps and their sounds signature or anything like that?

I am still planing to downgrad my voltage from LSR-350-48V to a lower voltage to 38V what is the most reasonable option?

 

[robertospeed]

Here are which speakers I play my TPA3255, Magnat Monitor Supreme 1002

 

[aon500]

I might have to upgrade to the EAUMT-0260-2 B Version to cycle trough OP amps myself

Is there a comprenhensive list for available Opamps and their sounds signature or anything like that?

I am still planing to downgrad my voltage from LSR-350-48V to a lower voltage to 38V what is the most reasonable option?

From DIY recommend OPA1656 or OPA1622 because both really good at 12V.

 

[somebodyelse]

I changed the OPA chips of my AIYIMA A07, put the OPA2604AP and the sound improved a lot, before the sound was inaudible and annoying and my ears hurt.
The NE5532 chips That mounts as standard, the sound is very dirty.

Obligatory question: what's your testing methodology?

 

[robertospeed]

Obligatory question: what's your testing methodology?

just my ears unfortunately

 

[meep-sama]

Just got myself one of these AIYIMA TPA3255 Amps (2.1 w/ BT version) for my entertainment setup:
https://www.aliexpress.com/item/33032214800.html?spm=2114.12010615.8148356.8.42846d7bt0QuNx

I wired it up with a mean well 48V 7.3A supply, and I noticed a small amount of mains hum. Even with the volume all the way down on the amp. I tried adjusting the voltage on the mean well with the amp on, and I noticed a change in the harmonic content of the noise. more fundamental at 48V, but as I swept down or up, I heard more high harmonics come out. I swapped out the power supply for another mean well using the same cabling, and the noise is still there, but at a slightly lower fundamental frequency! It's somewhere between E & F, not your typical 120Hz ripple.

To be honest, the noise is not unworkable. It's pretty low, but I'd like to see if it's fixable. Anybody have a clue what this issue is? Do the power supplies need better filtering, is it clocking noise, or just a quirk of the Class D Amp? Or something else I'm missing? (My first class D, don't judge)

 

[somebodyelse]

just my ears unfortunately

Thanks - I suspected that was the case, but good to be sure. I would expect the differences to disappear in a blind level matched test unless there's a design issue with the amp, but if you're happy with the sound and you had fun then that's a win.

 

[Bruce Morgen]

Just got myself one of these AIYIMA TPA3255 Amps (2.1 w/ BT version) for my entertainment setup:
https://www.aliexpress.com/item/33032214800.html?spm=2114.12010615.8148356.8.42846d7bt0QuNx

I wired it up with a mean well 48V 7.3A supply, and I noticed a small amount of mains hum. Even with the volume all the way down on the amp. I tried adjusting the voltage on the mean well with the amp on, and I noticed a change in the harmonic content of the noise. more fundamental at 48V, but as I swept down or up, I heard more high harmonics come out. I swapped out the power supply for another mean well using the same cabling, and the noise is still there, but at a slightly lower fundamental frequency! It's somewhere between E & F, not your typical 120Hz ripple.

To be honest, the noise is not unworkable. It's pretty low, but I'd like to see if it's fixable. Anybody have a clue what this issue is? Do the power supplies need better filtering, is it clocking noise, or just a quirk of the Class D Amp? Or something else I'm missing? (My first class D, don't judge)

If it's actually inadequate filtering that's at fault, it's easy to add more capacitance across the DC output of the SMPS using the additional "+ V" and "- V" screw terminals to see if that changes the symptom. I suspect it's that pesky BT circuit, which is active all the time so that devices can find it for BT pairing -- those cheap BT daughterboards can be problematic that way, especially in the very close quarters of a typical chip amp.

 

[aon500]

Just got myself one of these AIYIMA TPA3255 Amps (2.1 w/ BT version) for my entertainment setup:
https://www.aliexpress.com/item/33032214800.html?spm=2114.12010615.8148356.8.42846d7bt0QuNx

I wired it up with a mean well 48V 7.3A supply, and I noticed a small amount of mains hum. Even with the volume all the way down on the amp. I tried adjusting the voltage on the mean well with the amp on, and I noticed a change in the harmonic content of the noise. more fundamental at 48V, but as I swept down or up, I heard more high harmonics come out. I swapped out the power supply for another mean well using the same cabling, and the noise is still there, but at a slightly lower fundamental frequency! It's somewhere between E & F, not your typical 120Hz ripple.

To be honest, the noise is not unworkable. It's pretty low, but I'd like to see if it's fixable. Anybody have a clue what this issue is? Do the power supplies need better filtering, is it clocking noise, or just a quirk of the Class D Amp? Or something else I'm missing? (My first class D, don't judge)

I use AIYIMA A07 TPA3255 + 48V 7.3A supply too but no noise at all. Sorry I can't help.

 

[meep-sama]

If it's actually inadequate filtering that's at fault, it's easy to add more capacitance across the DC output of the SMPS using the additional "+ V" and "- V" screw terminals to see if that changes the symptom. I suspect it's that pesky BT circuit, which is active all the time so that devices can find it for BT pairing -- those cheap BT daughterboards can be problematic that way, especially in the very close quarters of a typical chip amp.

the fact that the frequency changed with a different supply is really tripping me out. But that does make a bit of sense. the damn blue light does not ever seem to stop flashing either... wish they had the same exact box but with the bluetooth on a switch. I did snag a stereo 3255 from them as well that has the BT on switch, so I will give that a try and see if I hear any noise.

 

[robertospeed]

Thanks - I suspected that was the case, but good to be sure. I would expect the differences to disappear in a blind level matched test unless there's a design issue with the amp, but if you're happy with the sound and you had fun then that's a win.

I have 3 TPA3255 AIYIMA A07 amplifiers and all 3 with the standard OPAs all sound the same, if you change the OPAs the sound changes, sorry but I'm Italian and I translate the language with the translator, I hope I have explained myself well.

 

[Ralferator]

I have 3 TPA3255 AIYIMA A07 amplifiers and all 3 with the standard OPAs all sound the same, if you change the OPAs the sound changes, sorry but I'm Italian and I translate the language with the translator, I hope I have explained myself well.

It's so strange that some people say that you can't hear a difference at all and others say the difference is huge. I don't get it

 

[somebodyelse]

It's so strange that some people say that you can't hear a difference at all and others say the difference is huge. I don't get it

It's just the way the brain works - it can fool us into percieving a difference when there isn't one, or failing to spot a real difference because you're not expecting one for that matter. It's well known and demonstrated in other fields, not just audio, and it's why any testing where you want to know if there's actually a detectable difference has to control for other factors that might influence the result. A non-audio example is food tasting happening under blue lighting to avoid the food colour influencing the perception of flavour. In audio, testing has shown that a small difference in signal level between 2 signals leads to both being apparently as loud as each other, but the one with the greater level usually being preferred. This is why we insist on level matching. Similarly blind testing removes the bias you may have, consciously or unconsciously. Fast switching is needed to get past auditory memory being short. Then there's statistics - occasionally you can throw 10 heads in a row, so passing an ABX once may not be convincing, but getting somewhere around 70% right every time you do it will show there's a difference but that it's not always detectable.

One problem with this is that until you try a properly controlled test you won't see the need for one - after all you clearly heard a difference! You may fortuitously spot the problem - many builders, both DIY and professional, have described the experience of having clearly heard the difference from a change, then discovering that they hadn't actually changed anything.

Another problem is that a properly controlled test takes quite a bit more effort and expense, and may be simply impractical. An ABX box for testing cables, DACs, headphone amps and the like may be relatively easy, but power amp switching is a bit harder, and there aren't many off the shelf examples so you'll probably have to build it. A robotic speaker switcher is beyond almost all of us. It's also not a lot of fun!

I'm not saying that there's never an audible difference between opamps or cables, but usually when there is an audible difference it's because there's a measurable defect with one of them. It's even possible you'll prefer the sound of the defect. Spending an afternoon doing uncontrolled tests is mostly harmless entertainment, so long as it doesn't become an expensive habit, but you should be aware of the limitations. If you start telling others that there's a clear difference you should at least tell them whether it was in a controlled test or not.