Articles, Reviews and Measurements of Audio Products

This is a review and detailed measurements of the Wyred4Sound mINT integrated stereo amplifier and DAC. It is on kind loan from a member and costs US $1,499 from the company. I see reviews dating back to 2013 so the box has been around for a while.

The design goes with the rest of Wyred4Sound gear although in person looks less refined than I expect in this price range:



The back panel shows some very good functionality such as triggers and home theater pass through:



The overall package is small and convenient from that point of view. It ran reasonably cool which was also nice.

As I took this picture, I realized USB only goes up to 96 kHz which is the old school USB interfaces of the time. Fortunately it is asynchronous which was novel at the time and could have been worse in the form of synchronous USB.

Wyred4Sound mINT Measurements
When I first powered on the unit, the measurements were low so to make sure...

This is a review and detailed measurements of the Gustard X26Pro USB balanced DAC. It was sent to me by SHENZHENAUDIO which sells it for US $1,499.

I must say, this is one of the heaviest and largest desktop DACs I have tested:



This is an unusual DAC in that it goes to extremes to implement everything on its own including digital filters for the DAC using a combo of ARM and Analog devices DSP. Many circuits are discrete and overbuilt. It is worth a read just to geek out on its design!

The back panel is the usual bits but an extra item in the form of external clock:



External clocks are used for synchronization in pro environment. Its application in home audio is dubious and my previous tests show it to have slightly worse performance, not better. I don't have...

This is a review and detailed measurements of the 600 ohm version of the Beyerdynamic DT 880 "semi-open" headphone. It was kindly sent to me by a member and costs US $198 on Amazon including Prime shipping.

I am not a fan of the silver color on the pads but otherwise, this is a good looking headphone:



The sample I have has been modified to have independent 3.5mm mono jacks and was supplied with a balanced XLR cord. The original has non-removable cord.

The cups are round and have inside diameter of 65mm and rather shallow 15 mm depth.

These are light headphones considering their size:


So overall comfort is very good although I found the fabric a bit scratchy.

Note: The measurements you are about to see are made using a standardized Gras 45C. Headphone measurements by definition are...

This is a review and detailed measurements of the DROP + MRSPEAKERS ETHER CX CLOSED planar headphones (made by Dan Clark Audio for Drop). Company reached out to me a couple of years ago to see if I would review them. At the time I was not testing headphones so said no but that I could use a low impedance headphone to test headphone amps. They offered the Ether CX and that is the main role they have had. Currently the Ether CX costs US $900 from drop.com.

I have been remiss in reviewing these because I have so many loaner headphones to test. Alas, it seems every day someone reaches out to me asking when I will test them so here we are.

The Ether CX has a professional and stylistic look to it with the carbon fiber finish:



Two sturdy XLR cables terminate in a 4-pin XLR with supplied adapters to other sockets.

Ether CX is a bit on the heavier side given its large size:



I find them comfortable to wear despite the...

This is a review and detailed measurements of the JDS Labs Atom Amp+ headphone amplifier. It was sent to me by the company and costs US $99. It was announced today.

The Amp+ follows the same recent industrial design in JDS amps and dacs:



It is light but functional. Dual gains are provided and single 1/4 headphone jack. The input selector chooses between 3.5 mm and RCA connectors in the back:



As you see power is provided through an external AC transformer.

JDS Labs Atom Amp+ Measurements
As usual we start with our "unity gain" setting which means the same input voltage is produced at the output. In the case of unbalanced amplifiers, I use 2 volts which is the nominal maximum output of desktop DACs:


I would expect stellar performance from JDS and that is exactly what we see. Distortion is incredibly low at -130 dB (15 dB better than threshold of hearing). A 60 Hz tone is also...

This is a review and detailed measurements of the Bose NC700 Bluetooth noise cancelling wired and wireless headphone. It was kindly purchased by a member new and drop shipped to me. The NC700 costs US $379 on Amazon including Prime shipping.

I must say, this is one of the most luxurious looking and feeling headphone I have seen:



The material is super soft-touch reminding me of silicone insulation on wires with such. The adjustment mechanism is super clever with that sliding bar which even allows some amount of movement for the cup. Top dollars were spent on mechanical and industrial design to be sure.

The cups are pretty small but still, mostly fit my ear. Inside dimensions are 70 x 56 x 24 mm (height, width, max depth). The cup depth is highly variable as the baffle is angled. The light weight of the NC700 helps a lot in comfort:



It took me two days to test what should have been a 2 hour affair. As with all...

This is a review and detailed measurements of the SMSL VMV A2 stereo "desktop" DAC and amplifier. It was sent to me by the company and costs US $999. VMV is the higher-end brand in SMSL lineup.

The look and feel of the A2 is similar to the latest line from SMSL:



It looks nicer though in this "widescreen" presentation. The rotary encoder feels a bit looks physically but is very responsive.

As noted, there is an integrated DAC in the A2:



I like the diagonal binding posts which gave me more room than I typically find in these smaller desktop amplifiers.

As set of stick on feet were provided that I did not like that much but they also supplied tall spikes which you may have to use to provide ample room for the little fan underneath to suck air into the unit:


I could not feel much air moving though as the only exhaust are the two slots in the back. I rather have something moving air than...

This is a review and detailed measurements of a Sennheiser HD 598 SE with replacement "leather" pads. It was sent to me by the owner with a funny note:

"Hello amirm. I have a pair of Sennheiser HD598s that I inherited. I hate them. I hate them the same way that one might hate a dog barking at 2 AM, or a romantic rival who stole one's lover. Please let me send them to you so you can justify my deep hatred. Then you can fire them into the sun."

The 598SE seems to be discontinued but it sold for $249.

I must say, I like the replacement pads as they felt quite nice to wear:



Helping with the comfort is the ultra low weight of these headphones:



I am not going to give you the cup dimensions since they are not the originals.

Note: The measurements you are about to see are made using a standardized...

This is a review and detailed measurements of the Rogue Audio Sphinx V3 integrated amplifier with tube buffer. It is on kind loan from a member and costs US $1,599.

The front panel of the Sphinx portrays a high-end look with its thick metal:



Alas, that thin metal surrounding it, takes that impression away. I liked the very wide apart inputs and output terminals which "should" bode well for crosstalk measurements:



There is good bit of weight to the unit courtesy of power transformer. I like the inclusion of the balance control. As you see in the first picture, I had to use it to get same gain out of both channels.

Protection circuit was well done with automatic recovery and worked great no matter how hard I pushed it.

Internal amplification is provided by a pair of Hypex UCD 180 OEM class D amplifiers. A buffer state made out of tubes completes the picture.

The amplifier has won many accolades as indicated by...

This is a review and detailed measurements of the OSD Nero Stream-XD analog and digital streaming (wifi and Bluetooth) amplifier. It was kindly sent to me by a member for testing. It costs US $230 from Amazon including Prime shipping.

There is a bit of heft to this box considering its budget category:



There is a rotary control for volume and input selection. Naturally with no display, you don't know the volume level. Various inputs are provided although USB is for storage device, not as a DAC:



I focused my testing on analog and Toslink inputs.

Like the inclusion of power supply in the unit which likely is the reason for some of its weight. In use, it got warm to touch but nothing concerning.

OSD Nero Stream-XD Measurements
Let's start with using the analog input and see how it does:



Well, this is not good. There is strange/high noise floor plus plenty of distortion...