• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

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

Neither.

It is rotated by 180 degrees from what you typically see. Min is at 1 o'clock, 50% at 6 o'clock and max at 11 o'clock.

Not a big deal at all.
.
Kind of funny, I bet I would mistakenly turn it clockwise many times before getting hang of it and probably cause max volume if its free 360 degree rotation.
 
That's like treble left bass right on my fosi audio bt20a, bass has always been left and treble right

Not fan of it but im interested in a o-noorus amp

Why do they do it like that ?

61+cd+AMZcL._AC_SL1500_[1].jpg
 
Well, finally had time to try out my D1. And well, the right channel is completely dead. Let's see how they will help to fix this.
 
The circuit board is inserted backwards, so it is different from the normal one, but it rotates clockwise.
If the movement is clockwise with typical potentiometer, the volume knob just needs to be fixed on the shaft which just points to min. and max. sweep with restriction to both ends like traditional amplifier.
I dont know why they made simple thing complicated and confusiing.
 
i appreciate they went to the bother of getting this chart out


42v (?) 5a does 95w 8 ohm so possibly as 80w unit at 48v 5a?
 
Can the speaker output of the D1 and D3 be highpass filtered when using the sub-out? Otherwise the sub integration will be tricky.
Haven't seen any information on that.
 
there's no ,main speaker cutoff

i dont think anyone does this in stereo units except for high end stuff like NAD M33s and the like and of course, home theater units.

i keep saying this is one of my main beefs with most manufacturers

i was only able to get good 2.1 integration if i chose my main speakers carefully... ie. i have two or three sets of speakers with main woofers in the 4-5in range that DO cut off at about 80hz and so therefore my test 8" subwoofer cuts IN at 80hz and so the integration is good.

but I would go further and say you kind of need to control the cutoff slope as well but that's a story for another day
 
Can the speaker output of the D1 and D3 be highpass filtered when using the sub-out?
There is no high pass filter on D1 or D3 amplifiers.

Otherwise the sub integration will be tricky.
Haven't seen any information on that.
I would, in fact, say that sub integration with D1 isn’t an issue as its low passed to 80Hz already.
However, main speakers get full bandwidth and so integration becomes less flexible there and you are stuck with whatever speaker crossover can do for you.
 
most of the speakers i own have good bass response... i mean that's what we care about

the speakers i'm testing now are 6.5" and with the typical DEEP cabinet design you get very good bass response and i found these to be not well integrated with a subwoofer

you can sort of control it by backing the power to sub down a fair bit but its not perfect

BUT the D1/3 series is very good with my floorstanding speakers and large bookshelfs
 
Well, finally had time to try out my D1. And well, the right channel is completely dead. Let's see how they will help to fix this.
I have figured out how the error occurs. If use T&P mode, which enables EQ the right channel dies completely. Left channel is OK, EQ works. Remote works, I can adjust volume.
If I enable BP mode both channels work, but even at level 1 volume out of 80 to amp plays way too loud. Also, the remote stops working completely. No EQ in this mode.
 
I have figured out how the error occurs. If use T&P mode, which enables EQ the right channel dies completely. Left channel is OK, EQ works. Remote works, I can adjust volume.
If I enable BP mode both channels work, but even at level 1 volume out of 80 to amp plays way too loud. Also, the remote stops working completely. No EQ in this mode.
Faulty unit.
 
wondering why they didn't try to hide PFFB circuit ;)
Why to bother if TI provided a public document with the design and implementation. It's not like they are Topping, Fosi or even Aiyima. LOL
 

Attachments

  • TPA324x and TPA325x Post-Filter Feedback slaa788a.pdf
    1.1 MB · Views: 67
Faulty unit.
Guddu. You did not have this kind of issue with yours, right? Can you confirm that in BP mode there is no volume control? only in B&T mode the remote controls the volume?
I'm still waiting for mine, I think it arrives today. There was a delay leaving China customs because they though it had a lithium battery inside or something.
 
Guddu. You did not have this kind of issue with yours, right? Can you confirm that in BP mode there is no volume control? only in B&T mode the remote controls the volume?
I'm still waiting for mine, I think it arrives today. There was a delay leaving China customs because they though it had a lithium battery inside or something.

I haven't had any channel imbalance or no audio issues with O-Noorus D1, it has some other minor issues like mild pop on using remote or potentiometer ON/OFF issues though which manufacturer said they have fixed in batches after mine.

Remote does not work in BP mode, only volume pot works by design.

I have posted detailed impressions here:

1715609211472.png
 
I haven't had any channel imbalance or no audio issues with O-Noorus D1, it has some other minor issues like mild pop on using remote or potentiometer ON/OFF issues though which manufacturer said they have fixed in batches after mine.

Remote does not work in BP mode, only volume pot works by design.

I have posted detailed impressions here:

View attachment 369268
Ok, so Bypass mode really bypasses the NJW1194 chip completely, that's why no volume control with remote. Interesting, it still uses the pot to control volume but bypasses the NJW194 chip.
The datasheet recommends to mute the amp before changing between modes:
1715610387983.png


Let's see if I get one from the new batch.
 

Attachments

  • NJW1194_E.pdf
    241.3 KB · Views: 57
Ok, so Bypass mode really bypasses the NJW1194 chip completely, that's why no volume control with remote. Interesting, it still uses the pot to control volume but bypasses the NJW194 chip.
The datasheet recommends to mute the amp before changing between modes:
View attachment 369271

Let's see if I get one from the new batch.
Changing mode without mute causes a pop sound, very faint but though.
 
there's no ,main speaker cutoff

i dont think anyone does this in stereo units except for high end stuff like NAD M33s and the like and of course, home theater units.

i keep saying this is one of my main beefs with most manufacturers

i was only able to get good 2.1 integration if i chose my main speakers carefully... ie. i have two or three sets of speakers with main woofers in the 4-5in range that DO cut off at about 80hz and so therefore my test 8" subwoofer cuts IN at 80hz and so the integration is good.

but I would go further and say you kind of need to control the cutoff slope as well but that's a story for another day
There are some but not many. Smsl a300, emotiva ta1, wiim amp (and these newer to be released units too) and there's a unit from rsl, dayton audio... I also can't understand why stereo units with sub out don't have hpf. It should be mandatory! lpf is actually useless in most instances as this can be controlled in most subwoofers themselves. Wiim Ultra would be a really nice pairing with this unit. A great all-in-one (two actually) system. Wiim amp pro seems like a good option but a bit underpowered maybe.
 
Hello! You don't know anyone since then who wouldn't measure up to Amirm's methods? I would be very interested in implementing SNR and PFFB. (or the amount of noise with the tone control turned on).
 
Back
Top Bottom