Articles, Reviews and Measurements of Audio Products
Nord One NC1200DM Signature Stereo Amp Teardown
I previously reviewed the Nord One NC1200DM Signature Stereo class-d amplifier. Here is a brief tear down of the same.
The NC1200Dm is a "dual mono" configuration with two power supplies, two hypex NC1200 amplifier modules and two NORD designed "buffer" (preamplifier) stages:
As I noted in the tear down of the Nord Three Purifi amplifier, I am not happy with the pair of voltage regulators in the buffer boards hanging in the breeze. Those heatsinks should be larger/heavier and soldered to the PC board.
I don't understand why the buffer stages are sandwiched between the noise power supply and power amp. They should be to the back of the unit.
I am pleased that no double stick tape is...
The NC1200Dm is a "dual mono" configuration with two power supplies, two hypex NC1200 amplifier modules and two NORD designed "buffer" (preamplifier) stages:
As I noted in the tear down of the Nord Three Purifi amplifier, I am not happy with the pair of voltage regulators in the buffer boards hanging in the breeze. Those heatsinks should be larger/heavier and soldered to the PC board.
I don't understand why the buffer stages are sandwiched between the noise power supply and power amp. They should be to the back of the unit.
I am pleased that no double stick tape is...
Discrete OpAmp Review: Sonic Imagery vs Sparkos
Recently I reviewed the Nord Three SE 1ET400A Dual Mono Stereo Amplifier. That unit came with the Sonic Imagery's 990ENH discrete operational amplifier ("opamp") in the buffer stage (pre-amplifier). The owner then ordered a set of Sparkos Pro SS2590 discrete opamps. This gave me a chance to compare the two in the same platform.
Alas, this analysis while of some value, won't be conclusive as power amplifiers can have temperature and run to run variations. Still, the Purifi 1ET400A modules are very low distortion so the data is more likely to be valid than not.
The opamps are socketed in the buffer board provided by Nord making swapping out easy. I especially appreciated the beefy gold coated pins which made it easy to pull them out and insert. Here is the original configuration with Sonic Imagery 990ENH:
...
Alas, this analysis while of some value, won't be conclusive as power amplifiers can have temperature and run to run variations. Still, the Purifi 1ET400A modules are very low distortion so the data is more likely to be valid than not.
The opamps are socketed in the buffer board provided by Nord making swapping out easy. I especially appreciated the beefy gold coated pins which made it easy to pull them out and insert. Here is the original configuration with Sonic Imagery 990ENH:
Schiit Magni 3+ and Heresy Headphone Amp Reviews
This is a review, detailed measurements and comparison of Schiit Magni 3+ and Heresy Headphone Amplifiers. It was kindly sent to me by the company. They both cost US $99 plus shipping from Schiit.
The Magni 3+ is a discrete amplifier implementation whereas the Heresy uses integrated circuits ("opamps") creating a race as to which is better.
Both units come in classic Schiit enclosure but the Heresy has burgundy accent with black top:
The Heresy has a nice red LED indicating if the power is on or not. The Magni 3+ does not. Why? Half the time I could not tell if the Magni 3+ was on or not.
The volume control on both is rather close to the 1/4 headphone jack. As such, even though I have thinner fingers, I could not comfortably change the volume control. Wish the headphone jack was on the left side and volume on the right.
Both units are powered by the classic AC transformer (15 volts AC @ 1.5 Amps) Schiit ships with a lot of...
The Magni 3+ is a discrete amplifier implementation whereas the Heresy uses integrated circuits ("opamps") creating a race as to which is better.
Both units come in classic Schiit enclosure but the Heresy has burgundy accent with black top:
The Heresy has a nice red LED indicating if the power is on or not. The Magni 3+ does not. Why? Half the time I could not tell if the Magni 3+ was on or not.
The volume control on both is rather close to the 1/4 headphone jack. As such, even though I have thinner fingers, I could not comfortably change the volume control. Wish the headphone jack was on the left side and volume on the right.
Both units are powered by the classic AC transformer (15 volts AC @ 1.5 Amps) Schiit ships with a lot of...
SONCOZ SGD1 Audio DAC Review
This is a review and detailed measurements of the Soncoz SGD1 Audio DAC. It was kindly sent to me by its designer. You can be forgiven for not knowing this brand. It is a new company formed by our member @Ben1987 who had previously designed the super popular Khadas Tone Board DAC! He has left and designed this much higher tier DAC. The SGD1 costs US $469.99 plus shipping from Amazon.
The design is unique for a desktop DAC:
The volume control is a rotary encoder. The ring around it indicates volume level. I sort of expected a numerical display to the left of it. You can easily set the input and filter types by how long you push the encoder in, and then rotating it.
Lots of inputs and outputs are available:
Nice to see Coax output and USB-C jack.
I don't see an external antenna but there is Bluetooth and one of the videos indicates Wifi capability!
DAC Audio...
The design is unique for a desktop DAC:
The volume control is a rotary encoder. The ring around it indicates volume level. I sort of expected a numerical display to the left of it. You can easily set the input and filter types by how long you push the encoder in, and then rotating it.
Lots of inputs and outputs are available:
Nice to see Coax output and USB-C jack.
I don't see an external antenna but there is Bluetooth and one of the videos indicates Wifi capability!
DAC Audio...
Vantec USB Audio Adapter (NBA-120U) Review
This is a review and detailed measurements of the Vantec USB Audio Adapter NBA-120U. It was kindly sent to me by a member. This thing has both microphone input (and hence ADC) and DAC+headphone amplifier. You get all of that including Prime shipping from Amazon for just US $10! Could be the bargain of the century....
The design departs from the usual shapes in a good way:
The unit is plug and play with windows. Alas, I could not get the ADC input to be recognized properly by my ASIO driver interface I have to use. Did not try to dig further to get it to work. Playback worked fine though so that is how the measurements are performed.
USB DAC Audio Measurements
As usual we start with our dashboard. Usually I drive the DAC at full digital amplitude ("0 dBFS") but the Vantec seriously distorted the output that way. So I dialed it down until that limit went away:
SINAD (measure of noise and...
The design departs from the usual shapes in a good way:
The unit is plug and play with windows. Alas, I could not get the ADC input to be recognized properly by my ASIO driver interface I have to use. Did not try to dig further to get it to work. Playback worked fine though so that is how the measurements are performed.
USB DAC Audio Measurements
As usual we start with our dashboard. Usually I drive the DAC at full digital amplitude ("0 dBFS") but the Vantec seriously distorted the output that way. So I dialed it down until that limit went away:
SINAD (measure of noise and...
Speaka USB DAC and Headphone Amp Dongle Review
This is a review and detailed measurements of an "old friend," the Speaka portable USB DAC and Headphone dongle. I say old friend as it is one of the first devices I tested and I gave it high marks. The unit was donated to me from a member in Germany. Shortly after the unit was no longer available at least in US. But another one, the
XtremPro X1-1 seems to be the same guts and is available for US $31 from Amazon including prime shipping.
I was requested -- and literally bribed with money -- to remeasure the Speaka with my new analyzer and metrics so comparisons become easier.
If you have seen one dongle, you have seen them all:
There are a couple of LEDs on it but I did not pay attention to what they do.
USB DAC Audio Measurements
Here is our usual dashboard:
I had to dial down the input by 1 dB as otherwise it clipped and performance dropped good bit.
SINAD (distortion and noise) is...
XtremPro X1-1 seems to be the same guts and is available for US $31 from Amazon including prime shipping.
I was requested -- and literally bribed with money -- to remeasure the Speaka with my new analyzer and metrics so comparisons become easier.
If you have seen one dongle, you have seen them all:
There are a couple of LEDs on it but I did not pay attention to what they do.
USB DAC Audio Measurements
Here is our usual dashboard:
I had to dial down the input by 1 dB as otherwise it clipped and performance dropped good bit.
SINAD (distortion and noise) is...
Schiit Modi 1 USB DAC Review
This is a review and detailed measurements of the original Schiit Modi DAC. It was sent to me by a member who was anxious to have it measured. I said not but that I would be open to a bribe to think otherwise. And the bribe came so here we are. If you are not interested in tests of these older products, please move along. I need money and will do anything to get some!
The original Modi DAC came out in 2013 I think at the same US $99 price that today's products come in as. At that time though, $99 was more of an amazing price for DAC than it is today. The enclosure of the unit looks just like today's DACs:
Schiit has over the years changed the color/texture of the enclosure so it may not match your modern Schiit gear. I think there are still variations even among the new gear. Not sure.
The back of Modi 1 has the bare minimum of connections:
This is all the functionality I need...
The original Modi DAC came out in 2013 I think at the same US $99 price that today's products come in as. At that time though, $99 was more of an amazing price for DAC than it is today. The enclosure of the unit looks just like today's DACs:
Schiit has over the years changed the color/texture of the enclosure so it may not match your modern Schiit gear. I think there are still variations even among the new gear. Not sure.
The back of Modi 1 has the bare minimum of connections:
Nord One NC1200DM Signature Stereo Amp Review
This is a review and detailed measurements of the Nord One NC1200DM Signature Stereo Amplifier. It is on kind loan from a member. With the options as tested, the cost is US $4,212. As the name indicates, the amp is based on Hypex NC1200 class D amplifiers plus some value add in the form of Sonic Imagery 990Enh buffers, very fancy speaker terminals and even directional fuse from Synergistic Research!
The enclosure is the same elegant design I have tested before with Purifi modules:
And here is the back panel connectivity:
The massive speaker terminals had no trouble handling my heavy speaker wires.
The trigger input is unusual in that it is supposed to fully shut of the unit, consuming no power (?).
The amps are mounted to the bottom of the case as is...
The enclosure is the same elegant design I have tested before with Purifi modules:
And here is the back panel connectivity:
The massive speaker terminals had no trouble handling my heavy speaker wires.
The trigger input is unusual in that it is supposed to fully shut of the unit, consuming no power (?).
The amps are mounted to the bottom of the case as is...
UpTone Audio EtherREGEN Switch Review
This is a review and detailed measurement of UpTone Audio's Ethernet "audiophile" switch. It is on kind loan from a member. The EtherRegen costs US $640.
The EtherRegen as the name indicates, "regenerates" and Ethernet signal. This is a functionality that is provided with any Ethernet switch that exists in the market. There are however claims of improvement which I will get into later. For now, the EtherREGEN comes in the same small aluminum enclosure rest of UpTone products come in:
Even though this seems to be the "back," it is the business end of the unit in that it has one special port ("B") that is supposed to be isolated from the ports on the other side:
The power supply is private branded but I am assuming that is just a sticker and UpTone has not really applied for FCC and regulator certification itself. This always puzzles me as companies like UpTone make a lot out of noise...
The EtherRegen as the name indicates, "regenerates" and Ethernet signal. This is a functionality that is provided with any Ethernet switch that exists in the market. There are however claims of improvement which I will get into later. For now, the EtherREGEN comes in the same small aluminum enclosure rest of UpTone products come in:
Even though this seems to be the "back," it is the business end of the unit in that it has one special port ("B") that is supposed to be isolated from the ports on the other side:
The power supply is private branded but I am assuming that is just a sticker and UpTone has not really applied for FCC and regulator certification itself. This always puzzles me as companies like UpTone make a lot out of noise...
Article: Impact of Color on Perception of Loudness
This is a digest of an interesting study I posted elsewhere on the impact of color on our perception of loudness. It is based on the paper presented at the International Congress on Acoustics (ICA):
Colour-influences on loudness judgements
Daniel Menzel, Norman Haufe, Hugo Fastl
AG Technische Akustik, MMK, Technische Universität München, Germany
Hugo Fastl is one of our authorities on psychoacoustics so when he talks, or rather writes, I take notice.
The test was simple enough:
In a nutshell, the listener would have to determine how loud something is while a color image was displayed in front of them on the LCD monitor. Different images were used for each trial. I will just post the one using controls that may be on some audio gear:
Depending on the color of said control, this is how the perception of identical sounds...
Colour-influences on loudness judgements
Daniel Menzel, Norman Haufe, Hugo Fastl
AG Technische Akustik, MMK, Technische Universität München, Germany
Hugo Fastl is one of our authorities on psychoacoustics so when he talks, or rather writes, I take notice
.The test was simple enough:
In a nutshell, the listener would have to determine how loud something is while a color image was displayed in front of them on the LCD monitor. Different images were used for each trial. I will just post the one using controls that may be on some audio gear: