Articles, Reviews and Measurements of Audio Products
Review and Measurements of Schiit Jotunheim With AK4490 DAC
This is a review and detailed measurements of Schiit Jotunheim DAC and headphone amplifier with its AK4490 DAC module. It is on kind loan from a member and in this configuration costs $499 plus shipping from Schiit direct. I had previously reviewed Schiit Jotunheim but that was with its multibit DAC. Some rightly objected that perhaps the performance of the unit was limited by its low performing DAC as opposed to headphone amplifier/pre-amp. In this test we remedy that two ways: 1) the included DAC uses the AKM Ak4490 DAC chip instead of multibit DAC used in the other unit and 2) I also test the pre-amp independently of the DAC.
The unit has the same bland, cost optimized packaging of other Schiit products:
The unit is mains powered so is quite hefty and sits...
The unit has the same bland, cost optimized packaging of other Schiit products:
The unit is mains powered so is quite hefty and sits...
Review and Measurements of KORG NuTube HA-KIT Headphone Amp
This is a review and detailed measurements of the KORG NuTube based, NuTekt HA-KIT headphone amplifier. It is on kind loan from our friends at Gig Harbor Audio. It comes in kit form and retails for USD $249.
If you are not familiar with "NuTube" is miniaturized triode vacuum tube. Here is the marketing statements from the company:
The KIT comes in awfully cute configuration of the "CMOY" headphone amps:
When powered up, you see two pretty blue lights when the tubes light up:
As you see, it runs on just two AA batteries which is stated to last 9 hours. Don't try this with your normal tube amplifier!
The tubes can be microphonic (generate electrical output based on vibrations) so they are mounted on rubber foam of some sort. Banging on the modul with my finger created a high pitched "biiiiing"...
If you are not familiar with "NuTube" is miniaturized triode vacuum tube. Here is the marketing statements from the company:
The KIT comes in awfully cute configuration of the "CMOY" headphone amps:
When powered up, you see two pretty blue lights when the tubes light up:
As you see, it runs on just two AA batteries which is stated to last 9 hours. Don't try this with your normal tube amplifier!
The tubes can be microphonic (generate electrical output based on vibrations) so they are mounted on rubber foam of some sort. Banging on the modul with my finger created a high pitched "biiiiing"...
Review and Measurements of HoloAudio XEME2VE USB to SPDIF
This is a review and detailed measurements of HoloAudio XEME2VE USB to SPDIF Converter. It allows you to connect a DAC that only has S/PDIF input to the USB jack of your computer. It is on kind loan from a member. Retail price appears to be USD $169 but the company has it on sale for USD $99.
As little boxes go, this feels unusually good and solid:
There is fair amount of heft to it which should stop most cables from tugging on it.
There are no external power supplies so all you have to do is connect the USB cable and S/PDIF to your DAC and you are in business. An indicator which shows it is powered on and happy would have been handy but is not critical in this application.
The XEME2VE is plug-and-play compatible with Windows 10 Creators Edition which means it is UAC2 compliant so should be driverless on Mac and Linux (or streamer of your choice).
Let's measure it to see how it performs.
Measurements
For these devices...
As little boxes go, this feels unusually good and solid:
There is fair amount of heft to it which should stop most cables from tugging on it.
There are no external power supplies so all you have to do is connect the USB cable and S/PDIF to your DAC and you are in business. An indicator which shows it is powered on and happy would have been handy but is not critical in this application.
The XEME2VE is plug-and-play compatible with Windows 10 Creators Edition which means it is UAC2 compliant so should be driverless on Mac and Linux (or streamer of your choice).
Let's measure it to see how it performs.
Measurements
For these devices...
Review and Measurements of Digital Amp DAC DAC HS
This is a review and detailed measurements of Digital Amplifier Company's DAC DAC HS (high spec) DAC. Yes, it is actually called that! It is on kind loan from a member. Seems like this was a kickstarter project. The unit tested is their first generation product and retailed for USD $1,290 I think. so not cheap.
What is cheap is the box that it comes in. It is basically a DIY project box with hobbyist like LEDs and such:
No effort was put in labeling the LEDs or the rear panel.
Disappointing in this price range is lack of USB input. You are limited to a single digital input: S/PDIF.
Output is through balanced XLR connectors which I like. But then again RCA outputs are missing.
An external small and light switching power supply powers the unit.
The owner supplied a HoloAudio XEME2VE USB/SPDIF converter which I tested the DAC DAC with at the end of the review.
Let's get into measurements and see if there is premium performance here to go...
What is cheap is the box that it comes in. It is basically a DIY project box with hobbyist like LEDs and such:
No effort was put in labeling the LEDs or the rear panel.
Disappointing in this price range is lack of USB input. You are limited to a single digital input: S/PDIF.
Output is through balanced XLR connectors which I like. But then again RCA outputs are missing.
An external small and light switching power supply powers the unit.
The owner supplied a HoloAudio XEME2VE USB/SPDIF converter which I tested the DAC DAC with at the end of the review.
Let's get into measurements and see if there is premium performance here to go...
Review and Measurements of SoundBlaster X-FI HD
This is a review and measurements of the SoundBlaster X-FI HD DAC/ADC and headphone amplifier. It is on kind loan from a member and it retails for USD $100 from Amazon with Prime shipping.
The box itself is plastic but doesn't look too bad:
The volume control is a rotary control of some sort with the worst feel positive. It is stiff with no notches and of course no indicators.
Connectivity is good though with headphone and microphone inputs in front and line out/in plus phono input in the back. We also have our usual set of USB, S/PDIF and Toslink inputs.
Plugging in the device into my Windows 10 did nothing so it is not UAC2 compliant. Went to get the driver and it is a 150 megabyte or so of what we used to call at Microsoft, "crapware." I used the custom install and disabled a bunch of stuff it wanted to install. Good news was that it also came with ASIO driver making it easier to test with my Audio Precision hardware...
The box itself is plastic but doesn't look too bad:
The volume control is a rotary control of some sort with the worst feel positive. It is stiff with no notches and of course no indicators.
Connectivity is good though with headphone and microphone inputs in front and line out/in plus phono input in the back. We also have our usual set of USB, S/PDIF and Toslink inputs.
Plugging in the device into my Windows 10 did nothing so it is not UAC2 compliant. Went to get the driver and it is a 150 megabyte or so of what we used to call at Microsoft, "crapware." I used the custom install and disabled a bunch of stuff it wanted to install. Good news was that it also came with ASIO driver making it easier to test with my Audio Precision hardware...
Marantz HD-AMP1 DAC and Integrated Amplifier
This is a review and detailed measurements of the all-in-one Marantz HD-AMP1 DAC and integrated amplifier. It is on kind loan from a member and retails for USD $1,100 including free Prime shipping from Amazon.
The unit has a somewhat retro looking of other Marantz audio products with the round digital display and wood sides:
There are both digital inputs and analog allowing one to build a complete system around the HD-AMP1. I was surprised to not see RCA outputs though so no convenient way to use its internal DAC by itself.
Amplification is through class-D technology which allowed the unit to run cool. Without permission from its owner though, I did not put it through thermal stress.
In addition to speaker output, there is also a headphone jack so I tested the output through that too.
There is a lot of functionality in HD-AMP1. I chose to test a few of them in this feature and will test more based on requests...
The unit has a somewhat retro looking of other Marantz audio products with the round digital display and wood sides:
There are both digital inputs and analog allowing one to build a complete system around the HD-AMP1. I was surprised to not see RCA outputs though so no convenient way to use its internal DAC by itself.
Amplification is through class-D technology which allowed the unit to run cool. Without permission from its owner though, I did not put it through thermal stress.
In addition to speaker output, there is also a headphone jack so I tested the output through that too.
There is a lot of functionality in HD-AMP1. I chose to test a few of them in this feature and will test more based on requests...
Battle of Battery Operated Portable Headphone Amps
This is a review, detailed measurements and comparison of two battery operated portable headphone amplifiers: then JDS Labs implementation of O2 and the Topping NX3s. The former is one that I own and it retails for USD which I purchased for about $140 including free Prime shipping. The Topping NX3s is on kind loan from a member and is a lot cheaper at just USD $59 on Amazon with free shipping. I believe it went on sale on Massdrop for $45???
Size wise, the Topping MX3s is much, much less chunky than the O2:
The NX3s is definitely pocketable and could I guess be strapped to the back of your mobile phone. No such prayer for the O2 amplifier. The NX3 feels quite slick while the O2 is like many DIY type products.
The NX3s uses any USB charge source which is very convenient. The O2 on the other hand uses a small but rather heavy AC mains transformer. AC can be converted to the positive and negative supplies easily for amplification...
Size wise, the Topping MX3s is much, much less chunky than the O2:
The NX3s uses any USB charge source which is very convenient. The O2 on the other hand uses a small but rather heavy AC mains transformer. AC can be converted to the positive and negative supplies easily for amplification...
Review and Measurements of ZorLoo ZuperDAC-S and SMSL IDEA Dac/AMPs
This is a review, detailed measurements and comparison of Zorloo ZuperDAC-S and SMSL Idea DAC and headphone amplifiers. They are both on kind loan from a forum member with him stealing the ZorLoo from his poor son. 
The ZuperDAC-S was apparently an Indigogo project and retails for USD $89 from their site. The SMSL Idea was the one I kinged as the best portable DAC/Amp a while ago so this is a refresher with my new measurement gear. It retails for USD $86 from Amazon with free Prime shipping. Assuming Zoerloo charges shipping, it will be more expensive of the two.
I will be presenting comparison data to recently portable DAC/AMPs such as DACPort HD and Audioquest Dragonfly Red and Black.
Both of these units distinguish themselves with onboard volume control through up/down buttons:
The SMSL Idea is certainly the nicer looking of the two. It is thinner but a bit wider and longer as you can tell in the above pictures.
Let's...
The ZuperDAC-S was apparently an Indigogo project and retails for USD $89 from their site. The SMSL Idea was the one I kinged as the best portable DAC/Amp a while ago so this is a refresher with my new measurement gear. It retails for USD $86 from Amazon with free Prime shipping. Assuming Zoerloo charges shipping, it will be more expensive of the two.I will be presenting comparison data to recently portable DAC/AMPs such as DACPort HD and Audioquest Dragonfly Red and Black.
Both of these units distinguish themselves with onboard volume control through up/down buttons:
The SMSL Idea is certainly the nicer looking of the two. It is thinner but a bit wider and longer as you can tell in the above pictures.
Let's...
Review and Measurements of NuPrime uDSD DAC/AMP
This is a review and detailed measurements of NuPrime uDSD DAC and headphone amplifier. I purchased this summer of last year from Amazon for USD $179 including Prime shipping.
This is a cute and very sturdy portable amp and dac:
It has really beefy RCA connectors in the back, the likes of which I have only seen in Khadas Tone Board. They would feel at home in gear retailing for a lot of money.
The enclosure is metal and while it is sturdy, cables can pull it around some.
Let's get into measurements and see if she is worth the extra premium over cheaper offerings.
Measurements
As usual I start with Dashboard measurements and there, I was initially very unimpressed with the results:
Remembering that some devices deteriorate in performance when their volume control is at max -- even though I am testing RCA out -- I lowered the volume to min and the situation improved significantly...
This is a cute and very sturdy portable amp and dac:
It has really beefy RCA connectors in the back, the likes of which I have only seen in Khadas Tone Board. They would feel at home in gear retailing for a lot of money.
The enclosure is metal and while it is sturdy, cables can pull it around some.
Let's get into measurements and see if she is worth the extra premium over cheaper offerings.
Measurements
As usual I start with Dashboard measurements and there, I was initially very unimpressed with the results:
Remembering that some devices deteriorate in performance when their volume control is at max -- even though I am testing RCA out -- I lowered the volume to min and the situation improved significantly...