Guddu
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Dear FMs,
This is "User Impressions, Observations and Owners Thread" for O-Noorus D4 Amplifier (or Stereo Receiver, as has ESS 9023P based DAC as well).
While we await if and when D4 get's measured on ASR, this thread hopefully will capture available details, features, internal pics, quick discussions on several aspects and user level testing, observations, issues and feedback on O-Noorus D4.
*** I hope other O-Noorus D4 users/owners feel free to sum up their feedback and some work arounds here to help other interested people.
Product Page: O-Noorus D4
Another thread which has some details and discussion: HERE
Here, I intend to summarize:
> what I get as a buyer or user of O-Noorus D4 amplifier/receiver
> aspects other than measurements that you might be interested in
> testing features & functions to see if there are any issues and how could get around those, if any
> I also hope that this thread could provide some information as to "what to expect" while you are buying this amplifier
O-Noorus D4 is packed with a loads of features, here is quick snapshot:
> Amplification: TPA3255 PFFB implemented
> ESS 9023P DAC with HDMI ARC, Optical, Coax, USB and BT digital inputs
> Front Panel:
- Toggle Switch to Power-OFF/Tone/Tone-ByPass
- Slim display to show selected input, displays RED LED illuminated input icons. Fixed brightness and color.
- Volume/Input-Select Knob - Moderate size volume knob for volume-control/Input-Select operation
- Tone Control Pots - Smaller in size knobs for Bass, Mid and treble adjustment. Works when Toggle is set to Tone.
> Back Panel:
- Digital Inputs:
- Bluetooth (ver 5.0), supports AAC, SBC, 44.1KHz sampling
***Note: Advertised name shows "O-NOORUS BT5.3B"
- HDMI ARC, Optical and Coaxial - supports upto 192KHz sampling, PCM Audio
- USB type "C" - 44.1 & 48 KHz sampling, no specific USB driver needed, also supports direct USB disk media playback
- Analog Input: RCA in (L + R)
- Subwoofer Out (SW) - Single RCA jack output, 80 Hz fixed low pass
Note: I didn't test or connect a subwoofer until now, never found need of one with Sierra-LX speakers
- Power Input: 24 - 48v DC Input, 5.5mm * 2.5mm plug/connector, 63v caps used for safer operation with 48v PSU
- Speaker Output: L + R, binding post/connectors are small
Some measurements/Spects from O-Noorus website:
Current Price & Availability
O-Noorus Website: No PSU: 109$, with 36v 5a PSU: 129$, with 48v 5a PSU: 139$
AliExpress: Currently 25% discount, No PSU: 80$, with 36v 5a PSU: 96$, with 48v 5a PSU: 104$
Amazon US: 48v 5a package only for 139$ with Prime Shipping and Free returns
Look & Feel:
> Its quite compact as their other amplifiers with smooth power-coat type finish, looks really good
> They only have BLACK color available at the moment
> Low profile makes things really easy for placement however speaker cable termination requires some considerations
> From available pics - Metallic heatsink is pasted onto TPA3255 chip which then also couples it to the chassis bottom, then the whole chassis operates as cooling solution
> D4 case doesn't have any ventilation holes/passage on sides or bottom, this is unlike their other amplifiers
Power Adaptor
> O-Noorus are including 48v GAN PSU with 48v PSU package
> I think the PSU as same or similar as the ones coming with Aiyima
Amplifier Internal or PCB Pictures from O-Noorus website:
Note: It uses Chemi-con Nippon KY 63v 2200uF capacitors, and dual power +/-12v for opamps
Idle Power Consumption:
> Powered ON but no audio playing
> Around 11watts
> Even, It keeps around 11watts if played arrox. up to 70-72 db SPL
Amplifier Case Temperature
> I played it a bit loud for my likings, around 80-85 db and the case temp. reached around 102F
Note: I used 48v 10a power supply all the time
Basic Observations - Hiss/Noise
> Input: RCA/HDMI/Optical/USB/BT
> Faint hiss/noise on tweeter, not audible from more than 1 feet
Note: My speakers have lower to modrate sensitivity, sensitive speakers may show slightly different results
Basic Observations - Power ON/OFF Pop
> Input: RCA/HDMI/Optical/USB/BT
> Faint but audible pop, not so audible from about a meter or so
> Input switching also generates faint pop
My Setup, Connectivity and Pairing devices:
nVidia Shield Pro (source) >>>> TV >>>> HDMI ARC & Optical >>>> O-Noorus D4 >>>> Ascend Acoustics Sierra-LX Speakers
PC (source) >>>> USB "C" & Bluetooth >>>> O-Noorus D4 >>>> Ascend Acoustics Sierra-LX Speakers
Subjective - O-Noorus D4 after continuous use of more than a week, primarily on HDMI ARC
Note: you might want to ignore this part as its purely based on my setup, in-room response and my likings
> Overall it performed as good as any other TPA3255 amplifiers in my setup.
> First thing I noticed was the power output, powerful presentation with clean and detailed sound.
> Noticeable stereo separation and quite balanced sound.
> I don't know how this amplifier measures in terms of SINAD or something but there wasn't anything unusual to notice in daily use.
***These are based on moderate listening levels around 75-80dB.
Observations which require rectification for better user experience and safer operation:
1) Audio Dropping
- I observed Audio dropping, specially in the beginning of a new file, song, movie, etc. It happens in the beginning and then becomes normal.
- O-Noorus are aware of this and they are working to get the firmware update created to resolve this, they are confident that it will be resolved with an update.
- Another D4 owner mentioned this issue in some post.
2) HDMI ARC Audio Negotiation
- When HDMI ARC is connected, source (TV) and ARC receiver (D4) need to agree on the volume level at the source.
- Currently they negotiate and agree on highest or full volume on source.
- What it means from a user point of view is that everytime you would restart TV, restart D4 amplifier, change input on TV or amplifier and then back to ARC - this will initiate the same full volume on source thing.
- So here, If you haven't set the volume to lover level on amplifier then you will have full volume blast upto amplifiers vlume settings.
- I accidently kept on getting into this issue even though I was aware of it.
- O-Noorus are aware of this and they are working to get the firmware update created to resolve this, they are confident that it will be resolved with an update.
Some other considerations and notes:
> D4 used OPA1642 OPAMPs, with swappable socket.
> I found D4 gave me higher output power compared to 3e A7 and Aiyima A80 with 48v 10a PSU.
> Speaker binding post - I had difficulty in using standard 4mm plugs, every time felt like it would damage something.
> D4 has multiple inputs which can be changed with front knob only, no remote and so manual effort needed to change the input.
> Volume control can not be bypassed, only tone controls bypass when BYPASS selected on front toggle switch.
> In some post, someone mentioned issue about PCB pins touching metal heatsink or something which caused several issues. My unit did not have such issues.
> D4 is using a closed case, I did not observe any considerable issue related to heat or thermals yet but you might have a different opinion if planning to use it in a crowded space without decent air flow.
> No balanced XLR/TRS analog input.
Overall, I think it is a good looking compact amplifier with tons of features along with PFFB design.
It performed very well in my setup, I will continue to report any functional or reliability issues here as I have connected D4 into my daily TV setup.
This is "User Impressions, Observations and Owners Thread" for O-Noorus D4 Amplifier (or Stereo Receiver, as has ESS 9023P based DAC as well).
While we await if and when D4 get's measured on ASR, this thread hopefully will capture available details, features, internal pics, quick discussions on several aspects and user level testing, observations, issues and feedback on O-Noorus D4.
*** I hope other O-Noorus D4 users/owners feel free to sum up their feedback and some work arounds here to help other interested people.
Product Page: O-Noorus D4
Another thread which has some details and discussion: HERE
Here, I intend to summarize:
> what I get as a buyer or user of O-Noorus D4 amplifier/receiver
> aspects other than measurements that you might be interested in
> testing features & functions to see if there are any issues and how could get around those, if any
> I also hope that this thread could provide some information as to "what to expect" while you are buying this amplifier
O-Noorus D4 is packed with a loads of features, here is quick snapshot:
> Amplification: TPA3255 PFFB implemented
> ESS 9023P DAC with HDMI ARC, Optical, Coax, USB and BT digital inputs
> Front Panel:
- Toggle Switch to Power-OFF/Tone/Tone-ByPass
- Slim display to show selected input, displays RED LED illuminated input icons. Fixed brightness and color.
- Volume/Input-Select Knob - Moderate size volume knob for volume-control/Input-Select operation
- Tone Control Pots - Smaller in size knobs for Bass, Mid and treble adjustment. Works when Toggle is set to Tone.
> Back Panel:
- Digital Inputs:
- Bluetooth (ver 5.0), supports AAC, SBC, 44.1KHz sampling
***Note: Advertised name shows "O-NOORUS BT5.3B"
- HDMI ARC, Optical and Coaxial - supports upto 192KHz sampling, PCM Audio
- USB type "C" - 44.1 & 48 KHz sampling, no specific USB driver needed, also supports direct USB disk media playback
- Analog Input: RCA in (L + R)
- Subwoofer Out (SW) - Single RCA jack output, 80 Hz fixed low pass
Note: I didn't test or connect a subwoofer until now, never found need of one with Sierra-LX speakers
- Power Input: 24 - 48v DC Input, 5.5mm * 2.5mm plug/connector, 63v caps used for safer operation with 48v PSU
- Speaker Output: L + R, binding post/connectors are small
Some measurements/Spects from O-Noorus website:
Current Price & Availability
O-Noorus Website: No PSU: 109$, with 36v 5a PSU: 129$, with 48v 5a PSU: 139$
AliExpress: Currently 25% discount, No PSU: 80$, with 36v 5a PSU: 96$, with 48v 5a PSU: 104$
Amazon US: 48v 5a package only for 139$ with Prime Shipping and Free returns
Look & Feel:
> Its quite compact as their other amplifiers with smooth power-coat type finish, looks really good
> They only have BLACK color available at the moment
> Low profile makes things really easy for placement however speaker cable termination requires some considerations
> From available pics - Metallic heatsink is pasted onto TPA3255 chip which then also couples it to the chassis bottom, then the whole chassis operates as cooling solution
> D4 case doesn't have any ventilation holes/passage on sides or bottom, this is unlike their other amplifiers
Power Adaptor
> O-Noorus are including 48v GAN PSU with 48v PSU package
> I think the PSU as same or similar as the ones coming with Aiyima
Amplifier Internal or PCB Pictures from O-Noorus website:
Note: It uses Chemi-con Nippon KY 63v 2200uF capacitors, and dual power +/-12v for opamps
Idle Power Consumption:
> Powered ON but no audio playing
> Around 11watts
> Even, It keeps around 11watts if played arrox. up to 70-72 db SPL
Amplifier Case Temperature
> I played it a bit loud for my likings, around 80-85 db and the case temp. reached around 102F
Note: I used 48v 10a power supply all the time
Basic Observations - Hiss/Noise
> Input: RCA/HDMI/Optical/USB/BT
> Faint hiss/noise on tweeter, not audible from more than 1 feet
Note: My speakers have lower to modrate sensitivity, sensitive speakers may show slightly different results
Basic Observations - Power ON/OFF Pop
> Input: RCA/HDMI/Optical/USB/BT
> Faint but audible pop, not so audible from about a meter or so
> Input switching also generates faint pop
My Setup, Connectivity and Pairing devices:
nVidia Shield Pro (source) >>>> TV >>>> HDMI ARC & Optical >>>> O-Noorus D4 >>>> Ascend Acoustics Sierra-LX Speakers
PC (source) >>>> USB "C" & Bluetooth >>>> O-Noorus D4 >>>> Ascend Acoustics Sierra-LX Speakers
Subjective - O-Noorus D4 after continuous use of more than a week, primarily on HDMI ARC
Note: you might want to ignore this part as its purely based on my setup, in-room response and my likings
> Overall it performed as good as any other TPA3255 amplifiers in my setup.
> First thing I noticed was the power output, powerful presentation with clean and detailed sound.
> Noticeable stereo separation and quite balanced sound.
> I don't know how this amplifier measures in terms of SINAD or something but there wasn't anything unusual to notice in daily use.
***These are based on moderate listening levels around 75-80dB.
Observations which require rectification for better user experience and safer operation:
1) Audio Dropping
- I observed Audio dropping, specially in the beginning of a new file, song, movie, etc. It happens in the beginning and then becomes normal.
- O-Noorus are aware of this and they are working to get the firmware update created to resolve this, they are confident that it will be resolved with an update.
- Another D4 owner mentioned this issue in some post.
2) HDMI ARC Audio Negotiation
- When HDMI ARC is connected, source (TV) and ARC receiver (D4) need to agree on the volume level at the source.
- Currently they negotiate and agree on highest or full volume on source.
- What it means from a user point of view is that everytime you would restart TV, restart D4 amplifier, change input on TV or amplifier and then back to ARC - this will initiate the same full volume on source thing.
- So here, If you haven't set the volume to lover level on amplifier then you will have full volume blast upto amplifiers vlume settings.
- I accidently kept on getting into this issue even though I was aware of it.
- O-Noorus are aware of this and they are working to get the firmware update created to resolve this, they are confident that it will be resolved with an update.
Some other considerations and notes:
> D4 used OPA1642 OPAMPs, with swappable socket.
> I found D4 gave me higher output power compared to 3e A7 and Aiyima A80 with 48v 10a PSU.
> Speaker binding post - I had difficulty in using standard 4mm plugs, every time felt like it would damage something.
> D4 has multiple inputs which can be changed with front knob only, no remote and so manual effort needed to change the input.
> Volume control can not be bypassed, only tone controls bypass when BYPASS selected on front toggle switch.
> In some post, someone mentioned issue about PCB pins touching metal heatsink or something which caused several issues. My unit did not have such issues.
> D4 is using a closed case, I did not observe any considerable issue related to heat or thermals yet but you might have a different opinion if planning to use it in a crowded space without decent air flow.
> No balanced XLR/TRS analog input.
Overall, I think it is a good looking compact amplifier with tons of features along with PFFB design.
It performed very well in my setup, I will continue to report any functional or reliability issues here as I have connected D4 into my daily TV setup.
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