Aiyima A80: TPA3255 Stereo Amplifier with ESS9038Q2M DAC: First Look

[pieterv1]

Learning

Not really. TPA3255/51 are completely differential amplifiers. In fact the RCA inputs are converted to differential by the second stage on each opamp. You could feed differential inputs directly into the amp and completely bypass the opamps. These Opamps are there to generate a slight gain on the first stage and the output from this first stage feeds the second stage to create an inverted signal from left and right inputs to feed the amp.

Okay thanks! Learning everyday!

Any idea if the amplifier does convert the analog inputs to digital?

Or will the digital circuitry & DAC be completely bypassed when using RCA/TRS?

 

[dr_mick51]

Learning

Okay thanks! Learning everyday!

Any idea if the amplifier does convert the analog inputs to digital?

Or will the digital circuitry & DAC be completely bypassed when using RCA/TRS?

I assume you mean as the Wiim Streamers? Where they take that RCA signal and then use an ADC to convert to digital so it can be passed via Optucal or Coaxial to another DAC?. I really dont think so. The RCA inputs on the TPA3255 amps pass through the attenuators (Digital or Analog) and then feed the opamps which feed the chip amp(bypassing the whole DAC section)
The DAC on this amplifier works the same as any other DAC, which takes the digital signal and outputs it to the digital volumen control. This chip (NWJ1194) has up to 4 different analog inputs(for example 1 from RCA, another from the DAC output, and the DAC controls the multiple digital inputs), but single ended output only. The big brother NWJ1195 has 8 inputs and differential outputs(2 per channel, 4 total). Oh and I forgot to mention that this digital volume chip also has tone controls which of course can also be bypassed( if implemented by manufacturer)
The O-NOORUS D3 was the first TPA3255 based amp to implement digital volume control (and remote control as well), and multiple digital inputs (BT, Optical and USB), then the D3 model dropped the DAC section(for people who already have a good DAC) but also added PFFB circuit and RCA inputs(of course) which the D3 did not have and this is how the D1 was created.
The future looks promising with this new generation of TPA3255 amps.

 

[ICIETDIYEUR]

Hello dr-mick51

Thank you for clarifying to the readers because I'm really not good at explaining what seems obvious to me just by looking at a PCB

 

[ICIETDIYEUR]

Precisely, I wanted to ask the following question to 3eAudio:

when I look at your illustration of the PCB of your A7 amplifier and more precisely the portion of the circuit located just after the balanced inputs (XLR/TRS), I see 3 OPAMPS....

In the caption it is written right next to it: "SINGLE-END TO BALANCE". I just think the terms are 'reversed' because we know very well what this assembly 'does' to the entant signals and also in terms of gain that are advertised in your product specification sheet with the use of these inputs.

Indeed, the term "SINGLE-END TO BALANCE" would be 'true' but only if it was about outputs, but this is not the case...

... don't tell me that they are only used to adjust the gain with regard to the higher input sensitivity (3.5 Vrms) in 'BALANCED' compared to that used in 'SINGLE-END' (1.75 Vrms).

 

[harkpabst]

I wonder why 3e Audio should monitor threads dealing with Aiyima amplifiers ... right when they are busy launching their own new product ... especially if their account isn't even tagged correctly ...

 

[Kakker71]

Hey all. I´m not that much into the technical details, but I like good sound.
I just ordered the A80 at Aiyimas website two days ago (yesterday it was sold out!)
I ordered the 48V 5A power supply and hope it´s enough. They say you can use 48V 10A for maximum output, and I might get that, if I´m not satisfied...
The reason I bought it:
I have a set of B&W DM683 S1 floorstanding speakers. I love them, but they are quite power hungry. Right now I have an old NAD C320BEE as preamp and a Hafler pro2400 power Amp (2*120W @ 8ohm). It´s not a traditional setup, but The NAD just hadn´t the power alone, and it sounds pretty good.
But now I´m planning to move the setup to our summerhouse, and the handling of two amps/DAC/Bluetooth ect. is a bit much for the wife....not to mention the lack of aesthetics
So now I try this little fella, which should fullfill all needs in one small package. Yes, I´ll degrade to about 102W pr channel, but I think I´ll survive and I can allways get the 10A powersupply if not.
I hope it can do the job!
And thanks for all the different comments in here! I love to learn!

 

[ICIETDIYEUR]

Do you think that 3eAudio is not keeping up with the news ?

 

[daniboun]

I find the performance, in anticipation, poor for a TPA3255 with a PFFB implementation.... I think we will have to wait for an ASR test with a comparison with the new O-Noorus D4

 

[orsib]

Hi.
On the circuit diagram (from Aiyima's website), I cannot see any indication of PFFB. They're not even mentioning it in the marketing material posted on the same site.
https://www.aiyima.com/products/aiy...DnwWAlXPeCkPXq7KZET1Rfp6wp12Uy5tHaD-psJcv2wVR

 

[harkpabst]

Hi.
On the circuit diagram (from Aiyima's website), I cannot see any indication of PFFB. They're not even mentioning it in the marketing material posted on the same site.
https://www.aiyima.com/products/aiy...DnwWAlXPeCkPXq7KZET1Rfp6wp12Uy5tHaD-psJcv2wVR

View attachment 413062

As mentioned before, Aiyima state that the A80 employs PFFB here and in their unboxing video on YouTube. There's also a (non-linked) reference to their Facebook group here. The results don't look exactly perfect, judging by Amir's testing.

To be fair, the load dependency of the Fosi V3 Mono pre-production sample as reviewed by Amir was not exactly convincing, either. Fosi later claimed that they had implemented improvements for the production units, but I don't remember any third party having confirmed this in independent review from the top of my head.

It's a low cost device after all.

 

[orsib]

As mentioned before, Aiyima state that the A80 employs PFFB here and in their unboxing video on YouTube. There's also a (non-linked) reference to their Facebook group here. The results don't look exactly perfect, judging by Amir's testing.

To be fair, the load dependency of the Fosi V3 Mono pre-production sample as reviewed by Amir was not exactly convincing, either. Fosi later claimed that they had implemented improvements for the production units, but I don't remember any third party having confirmed this in independent review from the top of my head.

It's a low cost device after all.

Thanks for the reply and sorry if I was in "write-only" mode. However it's still strange that such a "key feature" is not mentioned in the official marketing material.

 

[harkpabst]

However it's still strange that such a "key feature" is not mentioned in the official marketing material.

Absolutely and exactly what I thought.

 

[ICIETDIYEUR]

People hi

For the 'BALANCED' inputs to be considered 'real', they would have to go directly to the TPA3255 but there is the NW1194 digital volume control that does not know how to do this.

It would have been necessary to use a chip NJW1195 that knows how to do it so that the 'BALANCED' signal would be kept as 'original' until the chip TPA3255.

This confirms what I said and what dr_mick51 repeated by explaining better than I did

That said, fortunately (for the moment) we haven't yet addressed the possible 'ground loop' issues...... This could be an interesting topic

 

[harkpabst]

For the 'BALANCED' inputs to be considered 'real', they would have to go directly to the TPA3255 but there is the NW1194 digital volume control that does not know how to do this.

It would have been necessary to use a chip NJW1195 that knows how to do it so that the 'BALANCED' signal would be kept as 'original' until the chip TPA3255.

This confirms what I said and what dr_mick51 repeated by explaining better than I did

Sorry, but you didn't get that right. @dr_mick51 just confirmed that the TPA3255 is a fully differential amplifier, which of course it is. He also confirmed that the NWJ1194 has a single-ended output, which is also true.

What he did not confirm at all is that the balanced inputs would be fake in any way. Because they are not. They take a fully differential signal through a cable with proper opposite polarity input signal and a separate shielding. Nothing fake here.

 

[daniboun]

People hi !

I think you shouldn't rush and wait for the very next release of an O-NOORUS amplifier that takes the essence of this amplifier but with components that have better features (like the DAC ship, BT chip,...) as well as with additional features (like HDMI ARC )...
... it won't be long before you find out

I think it might be appropriate to ask O-NOORUS about this

PS: I don't understand why AIYIMA added (fakes) 'TRS' entries that don't bring ANYTHING AT ALL ???

Checkout : https://audiosciencereview.com/foru...255-pffb-hdmi-arc-es9023p.59185/#post-2162892

 

[daniboun]

As mentioned before, Aiyima state that the A80 employs PFFB here and in their unboxing video on YouTube. There's also a (non-linked) reference to their Facebook group here. The results don't look exactly perfect, judging by Amir's testing.

To be fair, the load dependency of the Fosi V3 Mono pre-production sample as reviewed by Amir was not exactly convincing, either. Fosi later claimed that they had implemented improvements for the production units, but I don't remember any third party having confirmed this in independent review from the top of my head.

It's a low cost device after all.

Marketing is like politics... you can say anything and everything. From the shared measurements, the Sinad shows more of a conventional TPA3255

 

[harkpabst]

Marketing is like politics... you can say anything and everything. From the shared measurements, the Sinad shows more of a conventional TPA3255

Yes, nothing to write home about.

 

[ICIETDIYEUR]

Good evening Mr harkpabst.

Your words are totally wrong and it seems obvious that you have misinterpreted dr'mick51's words but that in addition you do not know how to interpret the manufacturer's DATASHEET and do not have a minimum of knowledge of electronics to insist so much in error.

My intervention here is nothing personal and has not the slightest bad intention towards you but you cannot/must not peddle this type of error on a site that allows readers to enrich themselves with objective and verifiable data, that's all.

Have a good day to you.

Respectfully.

 

[harkpabst]

Good evening Mr harkpabst.

Your words are totally wrong and it seems obvious that you have misinterpreted dr'mick51's words but that in addition you do not know how to interpret the manufacturer's DATASHEET and do not have a minimum of knowledge of electronics to insist so much in error.

My intervention here is nothing personal and has not the slightest bad intention towards you but you cannot/must not peddle this type of error on a site that allows readers to enrich themselves with objective and verifiable data, that's all.

Have a good day to you.

Respectfully.

Unfortunately it's you who is wrong, so I have to keep warning the lesser informed readers about it. Sorry, nothing personal, indeed.

 

[ICIETDIYEUR]

I think that the intervention of a moderator who has technical knowledge should intervene in which case Amir himself since it is obvious that he knows his subject well.
I would like to thank in advance the staff of the forum whose intervention will allow readers to read the right information.
Accept my sincere greetings.