3e Audio SY-DAPx002 TPA3250/TPA3255 DSP Amplifier

[daftcombo]

@AfterThought you are almost right,there are 3 main reason for why we make this AIO amplifier.

1. combination with our current product with DSP,power supply and amplifier
2. within $100 budget but with good design and build quality.
3. build-in aluminum case for people who don't want build it as separated

for other idea and suggestion like USB/SPDIF/External I2S,higher performance ADC/DAC,we all understand this but only consider in further product if we continues to make it.

Hi,
Thanks for your replies. One more question:
On the TPA3255 models, does the fan start often ?

 

[AfterThought]

@AfterThought you are almost right,there are 3 main reason for why we make this AIO amplifier.

1. combination with our current product with DSP,power supply and amplifier
2. within $100 budget but with good design and build quality.
3. build-in aluminum case for people who don't want build it as separated

for other idea and suggestion like USB/SPDIF/External I2S,higher performance ADC/DAC,we all understand this but only consider in further product if we continues to make it.

It seems like an awesome product. I'm sure there are certain things that each person wants...but I understand that you need to make it to suit as many as possible AND keep the cost reasonable for consumer, and profit. For example, personally...I don't need optical, meanwhile another person does...it's not really reasonable to be able to have everything for a ~$100 price point. It seems like a nice thing to tinker with, expand, modify, etc.

 

[Marco54]

Hi all, my first post here.
I bought tpa3250 version, arrived in 10 days, no custom duties (!)
Impressions: awesome using bluetooth via ipad, better than using rca inputs ( auralic aries streamer > gustard x20 dac >rca). Using rca implies the signal goes to a/d conversion at the input of adau1701 and to d/a conversion at the output of this chip. So In my chain there is useless a/d and d/a conversion given that I don’t use the dsp at the moment.
Bluetooth signal undergoes only one d/a conversion at adau1701 output. I wonder if other people has the same impression quality sound wise. If this is true, solution could be a digital input.

 

[cyruz]

Hi all, my first post here.
I bought tpa3250 version, arrived in 10 days, no custom duties (!)
Impressions: awesome using bluetooth via ipad, better than using rca inputs ( auralic aries streamer > gustard x20 dac >rca). Using rca implies the signal goes to a/d conversion at the input of adau1701 and to d/a conversion at the output of this chip. So In my chain there is useless a/d and d/a conversion given that I don’t use the dsp at the moment.
Bluetooth signal undergoes only one d/a conversion at adau1701 output. I wonder if other people has the same impression quality sound wise. If this is true, solution could be a digital input.

Consider that using bluetooth you are trasmitting the files with a lossy codec. It's ok if you are playing mp3s at 320 kb/s, not so ok if you are playing lossless music.

 

[daftcombo]

Hi all, my first post here.
I bought tpa3250 version, arrived in 10 days, no custom duties (!)
Impressions: awesome using bluetooth via ipad, better than using rca inputs ( auralic aries streamer > gustard x20 dac >rca). Using rca implies the signal goes to a/d conversion at the input of adau1701 and to d/a conversion at the output of this chip. So In my chain there is useless a/d and d/a conversion given that I don’t use the dsp at the moment.
Bluetooth signal undergoes only one d/a conversion at adau1701 output. I wonder if other people has the same impression quality sound wise. If this is true, solution could be a digital input.

Thanks you for the good review. Do you have the possibility to do an ABX test to confirm that RCA doesn't sound as good as Bluetooth? That seems a bit difficult to admit because of the limitations of Bluetooth.

 

[zachery2006]

Consider that using bluetooth you are trasmitting the files with a lossy codec. It's ok if you are playing mp3s at 320 kb/s, not so ok if you are playing lossless music.

How did you compare the RCA and BT, did you set the same volume first? What's your impression in detail? I think many people will use it with RCA input.

 

[cyruz]

How did you compare the RCA and BT, did you set the same volume first? What's your impression in detail? I think many people will use it with RCA input.

I didn't, maybe you misquoted me

Regarding the matter at hand I think this can't be compared by listening, it's too subjective. The bluetooth codec used and the added processing could be the responsible for a more pleasant listening, but it doesn't mean it's technically superior to the ADC used before the DSP.

Moreover, the codec used by the bluetooth itself involves a decoding and a re-encoding, so the stream isn't "technically" pure.

 

[TimW]

We should keep in mind the input sensitivity. @Marco54 the ADC may be distorting with too hot of a signal.

 

[Marco54]

We should keep in mind the input sensitivity. @Marco54 the ADC may be distorting with too hot of a signal.

I’m using gustard dac as a preamp and so I suppose not to saturate rca input. Sy dap-x002 volume at max ( as power amplifier).
I’ll check by phonometer the spl to be the same.

 

[Toku]

When I purchased the SY-DAP1002 and did an operation test, the sound stopped on the third day.
When I stopped playing music after playing it for several hours in a row, the power was automatically turned off.
After that, I turned on the power again, but there was no sound from the speakers. The power ON / OFF, knob operation function, and volume LED display are normal, but there is no sound from the speaker.
After that, in order to reset the main unit, I unplugged the AC plug and left it for several hours to check the operation again, but there is still no sound from the speaker.
I switched all the connections to another amplifier, but the speakers, USB-DAC, and connection cable play normally without any problems.
Unfortunately from the symptom, it seems to be a hardware failure.
I've bought and trusted several amp boards from 3e audio so far, but this time it's a disappointing result.

 

[AfterThought]

When I purchased the SY-DAP1002 and did an operation test, the sound stopped on the third day.
When I stopped playing music after playing it for several hours in a row, the power was automatically turned off.
After that, I turned on the power again, but there was no sound from the speakers. The power ON / OFF, knob operation function, and volume LED display are normal, but there is no sound from the speaker.
After that, in order to reset the main unit, I unplugged the AC plug and left it for several hours to check the operation again, but there is still no sound from the speaker.
I switched all the connections to another amplifier, but the speakers, USB-DAC, and connection cable play normally without any problems.
Unfortunately from the symptom, it seems to be a hardware failure.
I've bought and trusted several amp boards from 3e audio so far, but this time it's a disappointing result.

That sucks to hear...I wonder if the chip itself died...have you tried to diagnose further?

73, N9RLI

 

[3eaudio]

@Toku
could you please share more info to us to understand the failure mode?

1. what is the operation test? input source and output power?with what load?
2. is no sound include both RCA and Bluetooth?
3. did you tried open the case to see any obvious failure?

 

[Toku]

That sucks to hear...I wonder if the chip itself died...have you tried to diagnose further?

73, N9RLI

@Toku
could you please share more info to us to understand the failure mode?

1. what is the operation test? input source and output power?with what load?
2. is no sound include both RCA and Bluetooth?
3. did you tried open the case to see any obvious failure?

Whenever I buy a device, I do a continuous operation test with the power on for a week to check the operation.

I used to have a lot of measuring instruments in my radio & audio shack, but now I have almost disposed of them at the suggestion of my family due to aging.
Therefore, detailed measurement check cannot be performed. Currently, I only have the legally required measuring instruments for the radio stations I operate.
I used to work at a large Japanese manufacturer, designing equipment for TV broadcasting stations. Therefore, I had a lot of equipment even in my private life. And elucidation of such troubles was my specialty.

Unfortunately, there is no schematic of SY-DAP1002, so many checks are difficult. Still, if you have an oscilloscope, you can track the signal line, but now you can't.
So far, I have only opened the cover of the amplifier and tested the soldering condition, the mounting condition of the parts, and the vibration test.
If you switch the connection from the silent SY-DAP1002 to another Chinese amplifier, it will work normally.

I also tested BT, but I can pair it, but there is no sound. Similarly, BT works fine with other amps.
The operation with the volume knob and the LED display are normal.
If you have any advice for checkpoints, I would like to implement it.

The red LED of the power supply blinks slowly when it is OFF, and it lights up brightly and continuously when it is ON. Is this correct?

The operating environment conditions of SY-DAP1002 are as follows.

RCA input source: Topping E30 & SMSL M500
BT input source: Oppo mobile phone R7
Speaker used: Home made
No1 (Tangband 10cm Full range unit 6Ω)
No2 (Tangband 12cm Full range unit 4Ω)

 

[Marco54]

I didn't, maybe you misquoted me

Regarding the matter at hand I think this can't be compared by listening, it's too subjective. The bluetooth codec used and the added processing could be the responsible for a more pleasant listening, but it doesn't mean it's technically superior to the ADC used before the DSP.

Moreover, the codec used by the bluetooth itself involves a decoding and a re-encoding, so the stream isn't "technically" pure.

I'm ashamed to say how stupid I was ..... the rca input (via auralic streamer) was equalized for headphones. I'm sorry for wasting time for all the forum readers. SY-dap1002 is really good and, you are right, rca input is better. Nevertheless bluetooth input is awesome.

 

[someone somewhere]

I do a continuous operation test with the power on for a week to check the operation.

Wow. It seems to me a week of continuous operation of the amplifier, in the case of which there are no ventilation holes - a serious test. Given the small internal volume of the sealed case.

 

[daftcombo]

I just ordered the SY-DAP2002 (TPA3255), 4 ohm version.

Will report when I get it!

 

[AfterThought]

Literally me since putting my order in...only with a cigar.

 

[Bushellj]

Hi all, my first post here.
I bought tpa3250 version, arrived in 10 days, no custom duties (!)
Impressions: awesome using bluetooth via ipad, better than using rca inputs ( auralic aries streamer > gustard x20 dac >rca). Using rca implies the signal goes to a/d conversion at the input of adau1701 and to d/a conversion at the output of this chip. So In my chain there is useless a/d and d/a conversion given that I don’t use the dsp at the moment.
Bluetooth signal undergoes only one d/a conversion at adau1701 output. I wonder if other people has the same impression quality sound wise. If this is true, solution could be a digital input.

Hi Marco

i have had one of the TPA3250 versions of this amplifier since they were first released. I use a Mac Mini as my primary source of Music. From my experience using the RCA inputs is much better quality than streaming via Bluetooth. I can do this as a direct A/B test and the difference is very obvious.

I actually wanted to use the Bluetooth function so I could stream from an Amazon Echo Dot but like everyone else on this thread the quality is very very bad as well as the volume being very low - It just isn’t workable in a practical system.

I really like the Amplifier as an integrated solution. The sound with the DSP managing all the inputs and volume might not be as good as a separate DAC but it’s not bad - in fact it really is rather good !!

 

[Ralferator]

@Toku
could you please share more info to us to understand the failure mode?

1. what is the operation test? input source and output power?with what load?
2. is no sound include both RCA and Bluetooth?
3. did you tried open the case to see any obvious failure?

These amplifiers just disappeared out of your Aliexpress shop - what happened? Don't you deliver to brazil anymore?

 

[Toku]

It's been a while since I reported the trouble with my SY-DAP1002, but I will report the result of my investigation.

Unfortunately, the advice on how to check from 3e audio was extremely difficult for me with presbyopia.
So I picked up a thin single wire with my fingers and touched the input PIN of the OPA1602A, which connects the tip of the wire to the input of the TPA3250. As a result, it was found that the analog circuit of TPA3250 was operating normally from the OP amplifier because a loud hum sound was emitted from the speakers on both the left and right channels.
The heatsink of the TPA3250 is also warm. Each operation with the knob is also normal.
So I determine that the cause is the ADAU1701 DSP circuit.