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3e Audio SY-DAPx002 TPA3250/TPA3255 DSP Amplifier

fsimen

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I received my DAP1002 two days ago and by now it's ok. I have to get my ear close to the speaker to hear the noise while idle.
 

Toku

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I received my DAP1002 two days ago and by now it's ok. I have to get my ear close to the speaker to hear the noise while idle.
From everyone's report, the cause of the noise seems to be the NE5532 attached to the DIP8 conversion board. The OP amp for the DAP1002 you purchased is the OPA1602. So I don't think there will be any noise problems.

The DAP1002 I purchased stopped producing sound in 2 days and is currently being returned to 3e audio to investigate the cause.
 

somebodyelse

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Thank you. got it.

so it’s 100W per channel in 4 ohm at about 31V... I’m wondering why limiting the chip capability with limited power supply.
Engineering trade offs to server the target market I guess - specifically cooling constraints given a small, low cost case and an internal power supply. Even with the limited output they've added a fan to keep things cool. More power would need more cooling, and probably bigger and more expensive PSU components, moving to a bigger and/or more expensive case and a different market segment. At least they're honest about its limitations, unlike sellers who just quote datasheet specs for a very cheap amp.
 

3eaudio

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Hi @zachery2006 @daftcombo and others amigos.
we did received your great feedback regarding the noise on our integrated amp and our engineer had deep into it and now come out a solution,
this can reduce the noise into a much smaller level,please see instruction as attached.
 

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3eaudio

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@molexey
  1. the 1st picture,the top one cap(100uF/6V) still need swap direction or remove.can you check that?
  2. the second picture,we only suggest change the PVDD rail capacitor(just use other band DIP part,SMT part can remove as not easy solder),not the MLCC on other rail,adding too much on that may cause start timing issue.
  3. with PFFB the coupling still there? from the picture it is removed.the reason why we not use on Rev1.0 and remove on Rev1.1,is because the performance is limited by DSP DAC, the amp itself is much better than DAC(please see picture 2 as a whole system test),so it make not big sense to include PFFB into this design.below you can see in amp section(no DSP DAC) test, blue curve is ordinal without PFFB,RED is with PFFB.
1609144070214.png

THD+N Ratio vs Measured Level-2.jpg
 

Lorenzo74

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Engineering trade offs to server the target market I guess - specifically cooling constraints given a small, low cost case and an internal power supply. Even with the limited output they've added a fan to keep things cool. More power would need more cooling, and probably bigger and more expensive PSU components, moving to a bigger and/or more expensive case and a different market segment. At least they're honest about its limitations, unlike sellers who just quote datasheet specs for a very cheap amp.
I agree and I like their transparencies.
But to me 50€ more to use the chip at it’s design spec would worth the purchase.
it would have been a perfect integrated amp with DSP (something like devialet high end amp with SAM...) This actually not. Now I’m using their DIY 2x265W stereo (60€) and a power supply 500W (800w peak) 70€ In a DIY case. compared with friends’ high end stuff it’s really not bad.
Best
 

molexey

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@molexey
the 1st picture,the top one cap(100uF/6V) still need swap direction or remove.can you check that
Yes, I reinstalled it. I didn't take all pictures.

@molexey
with PFFB the coupling still there? from the picture it is removed.
The coupling capacitors C93, C86, C70, C69 are still there. The R_in resistors also still there. But the amp didn't start. When I removed R_fb 18K resistors the amp started up as usual.

@molexey
the amp itself is much better than DAC(please see picture 2 as a whole system test)
Thanks for the measurements.
I understand this fact. But I want to try making analog balanced inputs.
 

coolize

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Hello guys , i just registered to confirm you guys the SY-DAP2002, I think the NE5532 is either fake or broken idk..
My speaker noise could be heard for like 3 meters away using the NE5532 supplied.
I went to try using a LM4562NA , and the noise is gone. So try changing the OPAMP guys.. see if the noise is gone
 

fsimen

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From everyone's report, the cause of the noise seems to be the NE5532 attached to the DIP8 conversion board. The OP amp for the DAP1002 you purchased is the OPA1602. So I don't think there will be any noise problems.

The DAP1002 I purchased stopped producing sound in 2 days and is currently being returned to 3e audio to investigate the cause.


Hi Toku,

I have opened my DAP1002 (REV 1.1) and the OP amp is NE5532. One thing I forgot to mention is that I only listened with Bluetooth input.

DAP1002 (REV 1.1) - inside picture.
 

Ralferator

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Hello guys , i just registered to confirm you guys the SY-DAP2002, I think the NE5532 is either fake or broken idk..
My speaker noise could be heard for like 3 meters away using the NE5532 supplied.
I went to try using a LM4562NA , and the noise is gone. So try changing the OPAMP guys.. see if the noise is gone

Ok all of this turns me away from the 3eAudio amps. They really need to take more care to deliver their amps without these troubles. The original NE5532 are so cheap - why to mess up a nice amplifier for a few cents?
 
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daftcombo

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Hello guys , i just registered to confirm you guys the SY-DAP2002, I think the NE5532 is either fake or broken idk..
My speaker noise could be heard for like 3 meters away using the NE5532 supplied.
I went to try using a LM4562NA , and the noise is gone. So try changing the OPAMP guys.. see if the noise is gone

Thank you very much!

@3eaudio advises to add 4 capacitors prior to the op-amps. You advise to replace the op-amps. What is the easiest and the best?

I'm afraid adding capacitors (RC filter) might alter frequency response and / or phase.
 

somebodyelse

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Has anyone got any measurements to show the changes with different opamps? Or done tests with known-good 5532s?
 

Sebbou

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Hi, I too registered to x2 confirm this issue on the 3e audio dap2002, with my polk rti a9 I can hear hissing noise 3 meter away from the speaker...
I normally put it on low volume to fall asleep with the music but with this amp I just cant the hissing noise is way too present.
I sent two message to 3e audio weeks ago but they never replyed but seen my message on aliexpress.. So i'm glad I found this forum to know I can switch the op amp. Just a shame that they cheaped for a few cents on those already cheap op amp.
 

coolize

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Thank you very much!

@3eaudio advises to add 4 capacitors prior to the op-amps. You advise to replace the op-amps. What is the easiest and the best?

I'm afraid adding capacitors (RC filter) might alter frequency response and / or phase.
TBH i changed my opamps right after 3eaudio advise to add 4 caps. For me myself , i'm not handy at doing these soldering stuff especially SMD stuff , even i couldnt find the C0G caps itself in my country.. so i just tried to change the opamps. Heres the supplied NE5532 , idk how to spot whether its legit one or not, but the label itself is scratched badly..
unnamed.jpg


Has anyone got any measurements to show the changes with different opamps? Or done tests with known-good 5532s?
i couldnt measure it though, but at least now the noise is very small at small volume and increases very little on the highest volume (RCA connected no audio played). Before , the noise is constant from low volume to high and can be heard from 3 meters away..

Hi, I too registered to x2 confirm this issue on the 3e audio dap2002, with my polk rti a9 I can hear hissing noise 3 meter away from the speaker...
I normally put it on low volume to fall asleep with the music but with this amp I just cant the hissing noise is way too present.
I sent two message to 3e audio weeks ago but they never replyed but seen my message on aliexpress.. So i'm glad I found this forum to know I can switch the op amp. Just a shame that they cheaped for a few cents on those already cheap op amp.

glad to find another one to confirm this.. yeah , my message also only read by him and not replied at all.. i just realized also that the NE5532 solder looks unclean ? is it shorting...? anyone know what happens if the opamps shorts each other pins ?
 
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spacevector

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Hi @3eaudio

Can you please confirm whether replacement of the opamp from NE5532 to OPA1602 is the preferred solution for SY-DAP2002? Or is it adding the capacitors you described in the document? Are you able test both solutions and report back which has lower noise?

All, where can I buy the OPA1602 soldered on the DIP socket? I am going to try to convince Amir to make this change before he tests the SY-DAP2002 and I do not think he'll want to solder these parts.
 

Toku

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Thank you for your information. It seems that it has become clear that the cause of noise is the OP amplifier.
In the new model, the OP amplifier is a socket type installation and can be freely attached and detached, so you can replace it with various OP amplifiers and check the change in noise.
In the early SY-DAP1002 I purchased, the OPA1602 was soldered directly to the board. There are no noise issues with this model.
 

3eaudio

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Hi @3eaudio

Can you please confirm whether replacement of the opamp from NE5532 to OPA1602 is the preferred solution for SY-DAP2002? Or is it adding the capacitors you described in the document? Are you able test both solutions and report back which has lower noise?

All, where can I buy the OPA1602 soldered on the DIP socket? I am going to try to convince Amir to make this change before he tests the SY-DAP2002 and I do not think he'll want to solder these parts.

there are 2 ways:
  1. Replace OP-AMP is easier way and can reduce noise to a certain level like 500-600uV
  2. By adding capacitor can get a little bit lower level to 200-300uV.
if you want test the unit please note it will be good to bypass DSP limiter,either the output power will limiter(when >100mS) to around 22Vrms.
you can email us then we can send you a bypass DSP image to do that.

THD+N Ratio vs Measured Level w Limiter_1.jpg
 

3eaudio

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Sorry for my English...
In DSP, can I just use the equalizer or add something else?

I am interested in the effect of LOUD.
sure you can ,the user section can be designed.
1609332342671.png
 
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