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

[Audionaut]

I could take it off with pliers, I scratched the button. Now I'll buy another one

I would like to avoid that.
I stopped pulling at the point when I thought more force would lead to some kind of destruction

 

[Alexander Lin]

Use the tail end of the pliers and the rubber part to hold the knob cap to avoid damaging it.

 

[Krampi]

In T&B mode
Click OK on the remote control several times until Color and then Brightness appear

Sequence>>>
Mode
Volume
Treble
Bass
Color
Brightness

Use the arrow keys to select the desired

@Audionaut Thank you!
Successsss!

 

[Audionaut]

Use the tail end of the pliers and the rubber part to hold the knob cap to avoid damaging it.

Thank you very much, Alexander, for your support, but I have the feeling that this button wants to stay where it currently is.
It is really very tight.

It also doesn't really matter and would only satisfy my play instinct, because it's not that I'm unhappy with the D1 and think that a different OP Amp would make fundamental improvements.

 

[Krampi]

Thank you very much, Alexander, for your support, but I have the feeling that this button wants to stay where it currently is.
It is really very tight.

It also doesn't really matter and would only satisfy my play instinct, because it's not that I'm unhappy with the D1 and think that a different OP Amp would make fundamental improvements.

... and it would do I recommend opa1656. Guaranteed to sound more pleasant than the 5532, for me.

 

[Krampi]

Good evening.

I don't want to "scatter myself" in endless explanations so here is in detail what was done on my amplifier in the hope that it brings enough answers to your questions ->
NOTE: for information, the gain here is the same as that of Lester's PCB in the "SE" version (Sylph Audio)

View attachment 409277

View attachment 409278
Explanations ->

View attachment 409279

View attachment 409280

NOTE: the NJW-1194 volume control has an input impedance of 15 to 20 kO, which is probably variable depending on the level setting, and which comes in parallel with the 10 kB resistor at the entry... So it's in your best interest to increase this resistor, you can go up to 100 kO or even 220 kO...

In electronics (not limited to audio), any active system has a resistance (input, output, etc.) that is never linear but varies +/- depending on the frequency of the signal.
We therefore use the notion of impedance to differentiate from pure resistance.

To come back to the pairing of devices:

In the case of HiFi, the ideal is for the output impedance of a device to be very small compared to the input impedance of the device to which it sends its signal.

The smaller the output impedance, the more current the device can "send", and therefore not be disturbed "too much" by its load (the load, here, is the device to which it is connected).

Conversely, the smaller the input impedance of a device, the more current it will "consume", and potentially disturb the source device. If output = low impedance --> not easily disturbed If input = high impedance --> doesn't disturb much.

We quickly understand that the 2 together is even better !

On the contrary, if the output impedance is high and the input impedance is low, very large signal disturbance in perspective (attenuation, distortion,....)

If the impedances are more or less equal, we will experience a good attenuation (math shows that if the impedances are equal, the amplitude of the signal is divided by 2 exactly), and we also run the risk of disturbance (distortion).

That's about IT.

Now, you're telling me that the values indicated on the diagram are not the ones on the amplifier ?
I suggest you measure them again or we don't have the same O-NOORUS D1 amp (of which I have the original diagram as well as those of the other models but also those to come, including 2 models very soon... but I didn't say anything) which has not undergone any modification unless there was to be a second version but this is not yet the case... For now.

Also you write that the best class D amps have a lower gain ?
Which ones, do you know it ? (FOSI, AIYIMA, TOPPING,....)
Can you tell me the gain of a PURIFI amp for example ?
Does it have a lower gain ?
I don't think Bruno (PUTZEYS) conceived it that way...
...and it seems to me that its direction is not too bad (LOL).

As far as resistance is concerned, the main thing is to take it with the right values: taking "GOLD" models, big brands or with high prices will have a much greater influence on the state of your finances than on the measurements.

Regards.

@ICIETDIYEUR
It seems that the SMSL DO100 Pro DAC can't drive the MOD D1 enough, what input signal level is needed to reach 100W 8 ohms? Also, will the excellent parameters be maintained with a possible increase in gain? Thank you! K'

 

[dr_mick51]

@ICIETDIYEUR
It seems that the SMSL DO100 Pro DAC can't drive the MOD D1 enough, what input signal level is needed to reach 100W 8 ohms? Also, will the excellent parameters be maintained with a possible increase in gain? Thank you! K'

You need 28.28V output swings. This means your input signal multiplied by total amplifier gain. TPA3255 with PFFB has around (not sure if D1 has been measured) 20dB or 10x gain. This requires an input signal of 2.828V to produce 100w at 8ohms. Therefore you will need a preamp.
Also, note that music plays 4 times lower than test tones. This means that producing 100W with test tones at 0dBFS requires 2.828V input signal (unless that's what you are planning to listen to), and for actual music you need a higher input.
For example, if you have a DAC capable of producing 2V output signal at 0dBFS, then the same DAC playing music will output 0.5V in average. Hence the importance of a preamp if you really want high power outputs. It is not enough just to get a bigger power supply, in fact my recommendation will be to get a preamp instead(or before) simply because you may not have been maxing up your power supply at all at your current input signal level. 0.5V x 10= 5V, then 5v^2 / 8= 25/8 W = 3.125W.
You will notice the volume increment right away with a preamp.

 

[meta1984]

Do not buy anything by o-noorus.
It is a bad company of bad people.
They sell me d4 with list of problems everyone of them make device useless and it is just like a stone with flashlights.
I send it back and what i get? Nothing.

I just lost my time and money. Stay away from bad people without hands and conscience

 

[Alexander Lin]

Do not buy anything by o-noorus.
It is a bad company of bad people.
They sell me d4 with list of problems everyone of them make device useless and it is just like a stone with flashlights.
I send it back and what i get? Nothing.

I just lost my time and money. Stay away from bad people without hands and conscience

My Russian friend, although your purchase is full of drama, please rest assured that AliExpress does not process that fast, so please be patient.

 

[Audionaut]

It is a bad company of bad people.

Dissatisfaction with a product can happen, but in my opinion it should be dealt with in a different way than insults in the public section of a forum.

 

[meta1984]

Dissatisfaction with a product

Product i ordered is ok.... On paper

2 days i lost on check this device (it is really my work?) and i must get a lot of videos to show their false (it is my favorite vacation).
15$ to i lost on send it back by post
They SELLING broken things without testing and have no idea why it is dramatic.
I lost 315$ for testing product of their ****** hands and no idea to say why and for what.

 

[Alexander Lin]

Product i ordered is ok.... On paper

2 days i lost on check this device (it is really my work?) and i must get a lot of videos to show their false (it is my favorite vacation).
15$ to i lost on send it back by post
They SELLING broken things without testing and have no idea why it is dramatic.
I lost 315$ for testing product of their ****** hands and no idea to say why and for what.

We will take responsibility for product problems, and there is a possibility that it may be damaged during transportation. We are very sorry about this.

 

[ICIETDIYEUR]

Hello.

I do think that something annoying must have happened during the transport

It can happen but it surely gets better

Regards.

 

[SciOcd]

So, long time lurker, just wanted to convey a few things here about this Amp. I love it, it sounds great (will be switching to a 48/5amp fosi power supply when it arrives with my V3), and it's one of the few PFFB amps in this range that has an actual volume controlled subwoofer out which is a really big deal IMO.

2 notes.

1. Volume control on the remote doesn't work, I take it this is a design limitation since the knob would need to move....

2. This is the really weird one. When I mute the unit, it does NOT mute the subwoofer out. Which for me is really very useful as i'm trying to figure out how much I would benefit from a subwoofer with my current Magnepan LRS+. I hooked up an old Logitech computer system sub to it, and it's very clear that yes, I need a decent sub. But it's kind of fun to be able to see exactly what things sound like below 80 hz on the fly with the mute button...

 

[dr_mick51]

So, long time lurker, just wanted to convey a few things here about this Amp. I love it, it sounds great (will be switching to a 48/5amp fosi power supply when it arrives with my V3), and it's one of the few PFFB amps in this range that has an actual volume controlled subwoofer out which is a really big deal IMO.

2 notes.

1. Volume control on the remote doesn't work, I take it this is a design limitation since the knob would need to move....

2. This is the really weird one. When I mute the unit, it does NOT mute the subwoofer out. Which for me is really very useful as i'm trying to figure out how much I would benefit from a subwoofer with my current Magnepan LRS+. I hooked up an old Logitech computer system sub to it, and it's very clear that yes, I need a decent sub. But it's kind of fun to be able to see exactly what things sound like below 80 hz on the fly with the mute button...

I think your amplifier is in BP (bypass mode). In this mode the remote functions stop working.
I think you can change it to the regular mode by pressing left or right on the controller. This also works for the other functions as soon as you get out of BP mode.

 

[SciOcd]

I think your amplifier is in BP (bypass mode). In this mode the remote functions stop working.
I think you can change it to the regular mode by pressing left or right on the controller. This also works for the other functions as soon as you get out of BP mode.

Thanks, appreciate it. I figured BP mode is the cleanest since i'm taking care of DSP/EQ (actually MSEB in hiby music via Fiio/Jade JM21) via my source and then DAC (Fiio K11 R2R). I'll switch over for that and see if it takes care of at least the remote issue, and hopefully the sub issue. Functionally, not muting the subwoofer when hitting mute seems like an oversight but it's actually kind of cool to mess around with.

 

[SciOcd]

Just got my Fosi V3 plugged in and tried it back to back with the D1. The D1 is much, much better even in terms of power, sound and distorition, even with the 36v/5a versus the 48/5 on the Fosi, but even more power using the 48v/5a fosi PSU on the D1. I'm just going to switch the power supplies and use the V3 for my KEF speakers on my computer system, but it's not a fair fight at all. The Onoorus D1 is way better than the Fosi v3 in basically every manner (except for the packaged PSU, basically). I mean, i only spent like $68 dollars for the V3 and 48v/5a from AliE, so still worth it just to play with but it's not a true competition, really I just wanted to the good Power supply and the amp was only like 20 dollars more than buying the power supply unit alone....