O-Noorus D3 PRO - A new TPA3255 PFFB amplifier with DAC

[Audionaut]

If I remember correctly, the D3 Pro was supposed to be launched on March 1.
Now it's April 25th and it's still not clear when and if the amplifier will be released at all.
This is a little disappointing and for the future it would be advisable to announce a concrete release date only when the product is actually ready for the market.

 

[Alexander Lin]

HI, ALL
We received the audio analyzer we purchased today and are currently getting familiar with it.
Previously, we sent it out for testing, which was very inefficient.
We are deeply sorry for the delay in the launch of D3 PRO.

The following is D3 PRO test SINAD results, I don't know if my settings are correct. If there is an error, please help correct the settings.

Test conditions: 5W output, RCA single-ended test.

 

[Alexander Lin]

@Alexander Lin , @ICIETDIYEUR Do you have some news for the D3 Pro availability and price ? Did you optimize the SINAD ? and implement a volume control left/right for the speakers level output ? Have a nice day.

Channel balance has been achieved.

 

[ICIETDIYEUR]

People hi


ALEXANDER, I would especially like to thank you for the transparency and honesty you show here towards future customers:

your attitude is truly unique

If your measurements are confirmed, then here is the following SINAD table to compare ->

I think it speaks for itself and I would like to know what the readers of the forum think ?

For my part, I think it is really 'correct' in view of all the possibilities that this amplifier will offer compared to those of the competition and their known flaws but this is, of course, only my personal opinion.

Indeed, to get a 'comparable' device (amplifier with integrated DAC and remote control) with a superior SINAD, you will have to spend 790€ for a YAMAHA AS-701 or 699€ for an AUDIOPHONICS DA-S250NC, which is not negligible in terms of budget nowadays.

I leave it to the readers to also compare with the price of the devices that offer a less good SINAD...

Have a good day everyone

 

[Guddu]

HI, ALL
We received the audio analyzer we purchased today and are currently getting familiar with it.
Previously, we sent it out for testing, which was very inefficient.
We are deeply sorry for the delay in the launch of D3 PRO.

The following is D3 PRO test SINAD results, I don't know if my settings are correct. If there is an error, please help correct the settings.

Test conditions: 5W output, RCA single-ended test.

View attachment 447638

Encouraging for sure.
A few queries, if you don’t mind:
What PSU is used?
What’s the gain set on amplifier for the testing?
What’s the volume level (knob position)? or bypass?
Planning to test with optical/usb/coax/ARC input as well?

 

[Alexander Lin]

Encouraging for sure.
A few queries, if you don’t mind:
What PSU is used?
What’s the gain set on amplifier for the testing?
What’s the volume level (knob position)? or bypass?
Planning to test with optical/usb/coax/ARC input as well?

48V5A PSU, the same as the power supply for D4.
GAIN: 29db
Test input path, AP->single-ended->NJW1194->OPAMP->TPA3255,
RCA input has no bypass function.
Optical/USB/coax/ARC test has not been tested yet, it seems that an additional AP module is needed.

 

[Guddu]

48V5A PSU, the same as the power supply for D4.
GAIN: 29db

Just wondering if 26dB could yield slightly better measurements.

Test input path, AP->single-ended->NJW1194->OPAMP->TPA3255,
RCA input has no bypass function.

Did you keep the amplifier volume at highest during test and adjusted on preamp/source or vice-versa?

Optical/USB/coax/ARC test has not been tested yet, it seems that an additional AP module is needed.

So no way for you to test digital inputs then?

 

[Alexander Lin]

Just wondering if 26dB could yield slightly better measurements.


Did you keep the amplifier volume at highest during test and adjusted on preamp/source or vice-versa?


So no way for you to test digital inputs then?

Volume at maximum position.

 

[Alexander Lin]

Usually, what is the volume setting? Maximum? Middle value?

 

[Guddu]

Usually, what is the volume setting? Maximum? Middle value?

View attachment 447783

Normally you would like to adjust it to the position to get desired gain keeping the desired power output (5w here).
As for Gain - Amir usually does 19dB for balanced input and 25 - 26 dB for RCA ( it used to be 29dB before).
You can notice the volume knob position in his measurement’s very first picture.

 

[Alexander Lin]

This is the final result. The noise floor may still have room for improvement.

 

[Audionaut]

Usually, what is the volume setting? Maximum? Middle value?

I follow your efforts with ambivalent feelings and wonder if and how the amplifiers of the earlier series, such as D1 and D4, were measured.
Were they measured?

 

[Alexander Lin]

I follow your efforts with ambivalent feelings and wonder if and how the amplifiers of the earlier series, such as D1 and D4, were measured.
Were they measured?

Of course, before, we did outsourced measured.

 

[Audionaut]

Of course, before, we did outsourced measured.

And now you've bought the equipment to do all the measurements yourself?
That's much better, because it makes it possible to directly adjust changes to the circuits.

 

[Guddu]

@Alexander Lin
How about other basic measurements like frequency response, multitone distortion? Are you able to get these on your tool?

 

[ICIETDIYEUR]

People hi

@ Guddu: I didn't quite understand your post about the gain used by amirm (?), the gain is intrinsically linked to the circuits used in an amplifier and will be used as such by its owner: why 'tamper' with the gain to make measurements when the end user won't do it ?

The measurements must reflect what the owner will get by using his device normally and not by any 'manipulation' which in some way will modify the device and may be worse if the technique used is not mastered.

In the case of an amplifier without volume control, the measured power will depend on the amplifier's fixed gain and the variable output voltage of the source (e.g., a DAC with variable volume).

In the case of an amplifier with volume control, the measured power will depend on the position of its volume knob (which varies the fixed gain determined by its circuits) and the source's fixed output voltage (e.g., a DAC without volume control).

 

[Guddu]

People hi

@ Guddu: I didn't quite understand your post about the gain used by amirm (?), the gain is intrinsically linked to the circuits used in an amplifier and will be used as such by its owner: why 'tamper' with the gain to make measurements when the end user won't do it ?

The measurements must reflect what the owner will get by using his device normally and not by any 'manipulation' which in some way will modify the device and may be worse if the technique used is not mastered.

In the case of an amplifier without volume control, the measured power will depend on the amplifier's fixed gain and the variable output voltage of the source (e.g., a DAC with variable volume).

In the case of an amplifier with volume control, the measured power will depend on the position of its volume knob (which varies the fixed gain determined by its circuits) and the source's fixed output voltage (e.g., a DAC without volume control).

Probably not worth a discussion as there isn’t any real difference in terms of benefits with 25 or 26 dB vs 29 dB shown in the measurements Alex showed for 5w, but higher gain has found to be measured a bit higher in noise/distortion (in general).
Many amplifiers have a jumper or a switch to adjust 3 - 6 dB for RCA, which is kind of useless in some cases if needed, Aiyima and Fosi have such small switches for RCA in some of their models.
Now think about how Alex figured the 25 dB gain in the last or final measurement…. just food for thought!

Edit: corrected

 

[Alexander Lin]

Probably not worth a discussion as there isn’t any real difference in terms of benefits with 25 or 26 dB vs 29 dB shown in the measurements Alex showed for 5w, but higher gain has found to be measured a bit higher in noise/distortion (in general).
Many amplifiers have a jumper or a switch to adjust 3 - 6 dB for RCA, which is kind of useless in some cases if needed, Aiyima and Fosi have such small switches for RCA in some of their models.
Now think about how Alex figured the 25 dB gain in the last or final measurement…. just food for thought!

Edit: corrected

I just turned the volume down.

 

[ICIETDIYEUR]

Just like anyone would do with a fixed output DAC or in the case of this amplifier with its built-in DAC...

...this amplifier does not have a volume bypass to make it a pure power amplifier: it already has a multitude of functions, which makes it rather 'unique'

 

[sabih]

Hi @Alexander Lin

Please also measure D4 so that we may know how much difference is there between the two amplfiers.