O-Noorus D1 - TPA3255 PFFB Stereo Amplifier - Front Display, Tone Control (with bypass) and Remote

[ICIETDIYEUR]

O-NOORUS D1 and D3...

Why not a D2 ?

Who knows...

 

[Guddu]

O-NOORUS D1 and D3...

Why not a D2 ?

Who knows...

D2 is work-in-progress.
It is going to be TPA3255 PFFB stereo amplifier with DAC (digital inputs).

P.E.... and probably HDMI ARC as well!

 

[ICIETDIYEUR]

Hi.

I really didn't expect it !

 

[Guddu]

Hi.

I really didn't expect it !

I have heard about few of their products in pipeline and their ideas are really good, don't know how big are they or their team but they aren't short on talent for sure.
- D2: DAC with TPA3255 PFFB amplifier, front digital display and subwoofer out, digital tone controls with bypass mode, probably remote as well
- D4: AKM DAC with TPS3255 PFFB amplifier, front digital display with ARC input and subwoofer out, digital tone controls with bypass mode, probably remote as well - Quite a complete package in my view
- A Dual-mono TPA3255 amplifier with PFFB topology, analog inputs
-and probably more.....

 

[ICIETDIYEUR]

I can't believe this !
Is this true ?
These people are not short of ideas, it should be interesting to be able to talk to them.

It promises some nice surprises in the future, it seems.
However, we really need to be able to have a more objective vision thanks to Amir's usual tests on these "materials"...

 

[ICIETDIYEUR]

Hi all.

I have an O-NOORUS D1 amplifier and the one I received does not have the defects mentioned by some people (luck or a manufacturer's revision ?).

One sure thing I can say is that the D1 is THE ONLY class D amplifier on the market (compared to the different FOSI or AIYIMA I owned) that allows listening at very low volume thanks to its digital volume control which, in addition to its reliability and precision, prevents channel imbalance and especially the "scratch fader" but also the "electrical noise" depending on the material used generated by a traditional potentiometer (I have to forget other flaws...) and this is really a plus that represents, in my humble opinion, an indisputable importance

It's the one I keep for sure and on top of that at the price at which it's offered, that's for sure !
All the more reason when it's the one I preferred from the point of view of its sound quality

I know in advance that you will consider this last comment as 'subjective' but that's normal since I'm the one listening to it...... But isn't it also what you also do with your hi-fi devices ?

A melodious day to all of you

 

[TonyJZX]

that's an interesting point

i believe this uses the NJW1194

the others use ANALOG vol. pots with their own log or 45 degree curves

but yeah i feel like the D3 with XLR would be pretty much the cap that suits many

 

[MCH]

, it should be interesting to be able to talk to them.

@Alexander Lin works for O-noorus and is member here

 

[Alexander Lin]

Yes, we are developing 3 models, D2, D4, D5.
D2 is an upgraded version of D3, with dual PTA3255, better DAC AK449S, USB xmos XU316, ....
D4: It is a three-band (100HZ, 1KHZ, 10KHZ) adjustable and optional bypass mode, multi-input amplifier,
D5 is an upgraded version of D1: balanced input, RCA input, dual tpa3255. It has a larger shell for heat dissipation.

 

[ICIETDIYEUR]

Hi Mister LIn.

I congratulate you on your D1: I like it very much, thank you.

Otherwise 2 TPA3255 must give off more heat for sure !
The power required must also be so with a large power supply ?

 

[Zoli64]

that's an interesting point

i believe this uses the NJW1194

the others use ANALOG vol. pots with their own log or 45 degree curves

but yeah i feel like the D3 with XLR would be pretty much the cap that suits many

The NJW technically suitable for this task, audiophile volume control? I used to deal with pga2311, I was satisfied with it, but that was 10 years ago.

 

[Alexander Lin]

Hi Mister LIn.

I congratulate you on your D1: I like it very much, thank you.

Otherwise 2 TPA3255 must give off more heat for sure !
The power required must also be so with a large power supply ?

The new model will dissipate more heat.

 

[ICIETDIYEUR]

OK.

This cannot be the NJW1194 since it is a two-channel...
With two TPA3255 in mono (so PBTL), you will need a chip designed for 4 channels since you seems to have mentioned balanced inputs too., no ?

So rather something that might look like this ->

Am I wrong?

 

[surroundman]

Please, make a model featuring subwoofer out with high-pass filter.

 

[Bleib]

Add if possible pop-suppression when changing modes

 

[FanatNsk]

One sure thing I can say is that the D1 is THE ONLY class D amplifier on the market (compared to the different FOSI or AIYIMA I owned) that allows listening at very low volume thanks to its digital volume control which, in addition to its reliability and precision

In fact, the Aiyiama D05 or Topping PA5 II can also be listened to at low volume, unlike the Fosi V3 or ZA3, which have a switch combined with a volume control.

I tested several amplifiers with digital volume control: O-noorus D3 and DA10, BRZHiFi X21 (two tpa3255), Aiyiama D05, low price amp on tpa3116 and I can say that the only inconvenience is that all amplifiers except D05 and X21 have the power button combined with the volume control and require a long press to turn on the device - this is not very convenient.

 

[FanatNsk]

Has anyone tested the input voltage for the RCA port at D1, what is the limit? My sound card outputs 2.2Vrms, I'm afraid that D1 does not support a signal greater than 1.3Vrms, as for example indicated in the specification at Topping.

 

[dr_mick51]

Has anyone tested the input voltage for the RCA port at D1, what is the limit? My sound card outputs 2.2Vrms, I'm afraid that D1 does not support a signal greater than 1.3Vrms, as for example indicated in the specification at Topping.

View attachment 390958

I'm pretty sure that what sensitivity means is the voltage required to provide max power with the potentiometer at max. Basically whatever voltage you provide is not attenuated and goes directly to the opamps and from there to the chip inputs and finally amplied (total amp gain). Basically is input voltage x amplifier gain. If you provide 2Vrms and the potentiometer at 10% then the voltage that is multiplied by the gain is only 0.2Vrms. Or you can provide 0.2Vrms and pot at 100% for the same effect. You should not worry, for me it is always better to provide a higher input signal(and that's because the DAC produces a cleaner signal at higher voltages(2vrms vs 0.2Vrms) which then is amplified by the amplifier.
On the example provided, the PA5 II . On rca it has 25dB of gain, that almost 6dB(or double) higher that on XLR. Therefore on XLR requires double the input voltage to reach the same max power.

 

[FanatNsk]

I had no problems with topping, but when I measured the frequency response in RMAA for O-noorus DA10 via miniJack 3.5mm input I could not get results because of overload, the output signal was with large distortions. Recently I measured fosi ZA3 via TRS balanced input, when applying a signal above 1V I observed distortions greater than 1%, at 900mVrms everything was fine.

 

[dr_mick51]

I had no problems with topping, but when I measured the frequency response in RMAA for O-noorus DA10 via miniJack input I could not get results because of overload, the output signal was with large distortions. Recently I measured fosi ZA3 via TRS balanced input, when applying a signal above 1V I observed distortions greater than 1%, at 900mVrms everything was fine.

Please, specify at what position was the potentiometer. If it was at 100% then a 1Vrms signal can easily become 30Vrms(at 29dB gain) output voltage which becomes (30Vrms)^2/4ohm=225W.
I'm not familiar with the DA10 amplifier, the info I found says it uses a TI chip called TAS5352.
Depending on the power supply voltage and the speaker impedance for example at 24v(which is the PS voltage the amp comes with) and 8ohms the amp produces only 40W at 10% THD+N. Not a very good performer.
Be aware that Amir's test used to be 0.16Vrms input signal with 29dB gain to produce 5W for the SINAD test.
Again I dont see any problem with what you have presented, everything seems to be in order according to specs.