O-NOORUS D4 budget stereo amp review

[LtMandella]

I have a question for Americans.... With Trump's new policy on import taxes from Chinese and European countries, won't it slow down purchases via Aliexpress and others? We're talking about a 25% increase

I am still ordering stuffed amp and preamp boards from Ali as of today. But then again I haven't seen any consequences yet to my purchases from the tariffs. So will have to see how onerous - if there are any for individual small retail purchases.
And I feel there is a good chance Tramp will cave on the tariffs very soon and therefore there will be no significant affect on my purchases, and this is mostly a market manipulation scam on his part, for his billionaire pals.

 

[capslock]

Hello Dany

Everyone seems to agree that the measurements on current devices are no longer audible.

Can we still talk about listening (necessarily subjective) when the devices don't have any perceptible differences ?

I don't know, but even reputable companies like TOPPING or SMSL offer settings on their DACs to obtain different 'sound signatures,' even though we probably shouldn't hear them since they use the same circuits but with different harmonics that we shouldn't hear ?

Personally, I haven't tested this type of DAC yet, so could anyone who owns one say whether they perceive any differences or not ?

What explanation could these companies provide if, however, differences were indeed audible ?
Are they hiding something new from us in terms of listening that they have discovered and measured (proven) ?

Given what is currently known, I have no personal answer to offer...

- 67 dB 3rd harmonic is audible in my experience.

If you don't use the DAC, you get - 80 dB which may be inaudible (in my experience, it may still make for a tired sound), but if you don't need a DAC, buy a D1 which has much lower distortion.

 

[mcdn]

Am I missing someone in this thread?... Anyways, thanks for the measurements, just wanted to ask, is the dummy load used your smd one? If yes, how did it go?

Oh, yeah, that thing is a tank! Obviously it wasn’t stressed at all by this amp. I’ve added active fan control recently, I’ll post an update soon

 

[mcdn]

Although SINAD is not very good, according to the feedback from 90% of users, D4 sounds excellent and has strong musicality.

That was my conclusion. It may not measure the best in class but it has great I/O and will be as good as any other amp in its intended use for desktop or small rooms

 

[mcdn]

- 67 dB 3rd harmonic is audible in my experience.

If you don't use the DAC, you get - 80 dB which may be inaudible (in my experience, it may still make for a tired sound), but if you don't need a DAC, buy a D1 which has much lower distortion.

Evidence needed please.

 

[mcdn]

Agreed.

For me,.. from now on PFFB does not matter and is a waste of money. Since subjectively non-pffb amplifiers are sounding better to my ears.
Just buy any lowest price TPA3255 amplifier and connect it to high quality DAC and you're good to go.

That’s not a very well justified conclusion. PFFB gives lower distortion and better FR in return for slightly lower gain. Almost all 3255 modules use it now.

 

[Alexander Lin]

That’s not a very well justified conclusion. PFFB gives lower distortion and better FR in return for slightly lower gain. Almost all 3255 modules use it now.

There may be EQ in the digital input part, which is designed by a third party. The EQ causes the SINAD to be low. We have obtained the source code and are trying to remove the EQ and then test the digital part.

 

[mcdn]

There may be EQ in the digital input part, which is designed by a third party. The EQ causes the SINAD to be low. We have obtained the source code and are trying to remove the EQ and then test the digital part.

That would be a great result, the power section does seem to be let down a bit by the front end.

To remind people, the 1kHz 5W dashboard SINAD is still a totally transparent 78.5dB and would be in the green section of Amir's master amp list. Yes, other TPA3255 implementations do better, but the overall package is still good value so long as you understand what it offers.

 

[sabih]

There may be EQ in the digital input part, which is designed by a third party. The EQ causes the SINAD to be low. We have obtained the source code and are trying to remove the EQ and then test the digital part.

When can we expect new firmware of this amplifier?

 

[sabih]

Hi @Alexander Lin

Any update on D4 firmware update?

 

[Alexander Lin]

Hi @Alexander Lin

Any update on D4 firmware update?

Not finished yet.

 

[noise]

I was looking at the Douk A5 Pro, but this option looks interesting. Is the performance of this amp really much different than the A5 Pro? Hard to tell with the back and forth. The current sale price is fairly low which makes this amp a great value.

@Alexander Lin If there's a DSP, would it be possible to have different firmwares compiled or maybe some way of getting a special mode to set and dial in a high pass filter?

 

[Alexander Lin]

I was looking at the Douk A5 Pro, but this option looks interesting. Is the performance of this amp really much different than the A5 Pro? Hard to tell with the back and forth. The current sale price is fairly low which makes this amp a great value.

@Alexander Lin If there's a DSP, would it be possible to have different firmwares compiled or maybe some way of getting a special mode to set and dial in a high pass filter?

Regarding the high-pass filter, it will appear on the D1 PRO. It can be controlled by remote control, with a cutoff frequency of 40~300hz and a third-order filter.

 

[noise]

Regarding the high-pass filter, it will appear on the D1 PRO. It can be controlled by remote control, with a cutoff frequency of 40~300hz and a third-order filter.

Is it a DSP based filter or analog? The D1 looks really interesting with mostly what I am looking for. When is the PRO version coming out? If it's still in development, it would be cool if it had stereo RCA and a 3.5mm TRS input that are mixed together so two audio sources can commingle with the amp without needing to switch between sources.

 

[noise]

I found some odd issues with the amp so far. There is a big difference in volume between the bypass and tone modes so it's difficult to quickly check the differences between them and it is also jarring. The button switching the inputs is lacking a proper debounce, so it can be unpredictable. I think at least once I had to disconnect power to get the unit to detect sound from the RCA inputs when I couldn't hear anything. Also some feedback on the interface: the small icons are difficult to differentiate.

 

[nickb2b]

Hi @Alexander Lin. I have the D4 and really love the sound this little guy is putting out, but I have a question about the ARC feature. I've set my TV to use ARC (instead of eARc) and can only get sound out of the amp if I power off the TV and amp, and then power on the amp first before turning on the TV. When the TV goes into power saving mode it defaults to the internal speakers when I turn it on and I have to go through this power on/off cycle for the sound to come out of the amp. Have you had any other reports of this happening, and is this something that can be fixed with a firmware update? Thanks.

 

[Alexander Lin]

Hi @Alexander Lin. I have the D4 and really love the sound this little guy is putting out, but I have a question about the ARC feature. I've set my TV to use ARC (instead of eARc) and can only get sound out of the amp if I power off the TV and amp, and then power on the amp first before turning on the TV. When the TV goes into power saving mode it defaults to the internal speakers when I turn it on and I have to go through this power on/off cycle for the sound to come out of the amp. Have you had any other reports of this happening, and is this something that can be fixed with a firmware update? Thanks.

A firmware update can solve this problem.
Currently the TV is set to default to ARC input, and the amplifier checks for arc after powering on.

 

[noise]

A firmware update can solve this problem.

wen firmware update?

 

[Alexander Lin]

wen firmware update?

On August 30th, there was a version update.

 

[sabih]

On August 30th, there was a version update.

Please share link of firmware update and instructions