Articles, Reviews and Measurements of Audio Products (As an Amazon Associate I earn from qualifying purchases)

Review and Measurements of CHORD Qutest DAC

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This is a review and detailed measurements of CHORD Qutest DAC. It is on kind short-term loan from Gig Harbor Audio. I previously tested a the older generation, Chrodette and 2Qute DACs so naturally members were curious how the current product line performs. The retail price of the Qutest is USD $1895.

As I have noted before, CHORD uses a custom implemented DAC instead of using an existing DAC chip. The design sports very long tap filters as to better approximate an ideal low pass filter required for all digital to analog converters.

The unit is similar to older generation but feels a lot more hefty. It has the new iconic bubble light controls of other CHORD products:
CHORD Qutest DAC Review.png.jpg

Regular readers of the forum know that I am not a fan of this interface. While it is...

Review and Measurements of DACPort HD and Dragonfly Red

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This is a review and detailed measurements/comparison of AudioQuest Dragonfly Red and CEntrance DACPort HD portable, "thumb drive" sized DAC and headphone amplifiers. Both are kind loan from members. The Dragonfly Red retails for USD $200 from Amazon and DACPort HD for $179.

Physically the DACport HD is fair bit larger than Audioquest although in grand scheme of things, the differential is small:

CEntrance DACPort HD and AudioQuest Dragonfly Red USB DAC and Headphone Amp Review.jpg

The Dragonfly Red is made out some kind of metal and runs very cool. The DACPort HD is made out of lighter weight aluminum and runs fair bit warmer.

The DACPort HD has volume control and low/high gain, neither one of which exists on AudioQuest Red. It also supports a range of formats up to 384 kHz PCM sampling and DSD while the Dragonfly Red is stuck in the last decade, limited to 24-bit/96 kHz PCM only.

The DACPort HD requires a cable to connect to USB Port. The Dragonfly as you see just plugs in.

Let's get into measurements and see...

Review and Measurements of Sony RSX-GS9 Car Receiver

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This is a review and detailed measurements of Sony RSX-G9 high-end Car Media Receiver. It is on kind loan from a member. It retails for USD $1,499 so at the top of class when it comes to the category. In case you have not kept up, "Media Receiver" indicates the unit has no CD drive. So all media playback is through bluetooth and unusually so here, a host computer or phone using the RSX-G9 as a USB DAC.

Sony has done its part to make the unit look higher-end although there is so much you can do in a DIN configuration:

Sony RSX-GS9 Car Media Receiver Review and Measurements.jpg

I am not a fan of the stiff volume control with no detents. The switches feel fine.

Sony's Media Controller works really well in managing the RSX-G9 remotely. Bluetooth pairing is made trivial by use of NFC which auto-pairs the unit. In the case of my Samsung S9 though I had to find the NFC spot to make this work. A down side of this pairing is that you need to do it every time the unit is powered on. At least...

Review and Measurements of Hypex NC400 DIY Amp

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This is a review and detailed measurements of a DIY power amplifier based on Hypex NC400 amplifier modules. It was built and is on kind loan from a member. I asked him to list the parts and this is what he supplied:
So putting aside labor, it is about USD $1,100. From outside, the unit looks very professional, sans branding:

Hypex nc400 DIY Power Amplifier Review and Measurements.jpg

The unit came with balanced inputs and speaker outputs and that is how I tested it.

The amplifier as noted is based on Hypex NC400 modules. If you don't know much about it...

Review and Comparison of CHORD Chordette and 2Quete DACs

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This is a review and detailed comparison of two CHORD DACs: the discontinued Chrodette and 2Qute. They are both used and on kind loan from our local audio store: Gig Harbor Audio. The Chordette seems to have listed for USD $799. The list price for 2Quete is USD $1,295.

Both units look remarkably similar from the outside with TOSLINK optical, S/PDIF coax and USB inputs. On 2Qute there is an input selector. There is none on Chordette and it seems to autoselect the input.

CHORD Chordette and 2Qute DAC Review.jpg

I first tried to operate the units using USB input but had no luck with my previously installed CHORD drivers. I downloaded the Windows 7 drivers and still had no luck. So for this review and testing I resorted to using the S/PDIF input.

Typical of other CHORD products, user interface is odd with a large lens on top of the units amplifying LEDs of different colors.

Unlike many DACs we test, these CHORD units have...

Review and Measurements of Audio-gd R2R11 DAC & Amp

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This is a review and detailed measurements of Audio-gd R2R11 DAC and headphone amplifier. It is on kind loan from a forum member. It retails for USD $350 plus shipping. From what I can tell, you have to send money via paypal and then the product will be shipped to you as there is no formal online store. Customers in Europe though can purchase it from distributors there. The only price I see is 369,00 € tax included.

I have had many requests to measure this unit and I am very happy to finally get one to review. The unit being an unconventional, discrete "R2R resistor ladder," as opposed to vast majority of DACs we test which are built on integrated DAC ICs (chips). This brings an appeal to many people, considering such DACs as more natural sounding. This has made this DAC and the ones like it from Schiit, etc. very popular.

This is the lower-end of DAC products from Audio-gd and as a result dispenses with displays and such:

Audio-gd R2R11 DAC and Headphone Amp Review.psd.jpg

Review and Measurements of MARCH audio dac1

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This is a review and detailed measurements of the new MARCH audio dac1 dac. It is the brainchild of our member @March Audio and is on loan to me. It retails for USD $449 but has an introductory price of $380 as of this writing. The company is located in Australia which should be an advantage for people living there with respect to purchasing this unit.

Alan's approach to audio hardware is highly minimalistic from features to design ID. It comes in machined block of aluminum which gives a nice impression of quality:
MARCH Audio dac1 Review.png.jpg

As you can tell there is only one indicator in the front in the form of a red LED indicating the unit is on. There is no power switch and the unit is powered by the same USB-c cable that feeds it. A pair of high-quality RCA jacks complete the unit. Alan's philosophy is emphasis on computer for control and management so you don't find volume control, etc. on the unit. It does what software cannot do...

Audibility thresholds of amp and DAC measurements

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A recurring theme on ASR is whether or not the various measured qualities of the devices are audible. In this post, I'll present some clear and visual thresholds for when those imperfections can be considered a potentially audible concern. I will not explain the basics of amp/DAC measurements.
Feel free to comment if you have any issues with the content of this post, be it technical, grammatical, or maybe just something that's poorly communicated.

Orange marks strict limits while green marks lenient limits.
UPDATE #1: There seems to be some confusion about the the implications of the thresholds in relation to audibility.
Strict thresholds guarantee that anything measuring better will be transparent.
Lenient thresholds are only lenient relatively to the strict thresholds, but are still very strict themselves from an audible point...

Review and Measurements of Schiit WYRD USB Filter

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This is a review and detailed measurements of Schiit WYRD "USB decrapifier." It is on kind loan from a member and retails for USD $99 plus shipping from Schiit direct.

This is a box that has USB input and output and external transformer input. It generates new USB power using the latter, and reclocks USB using a USB hub chip with the claim of it being more accurate. Externally it looks like the rest of the budget products from Schiit except that it has yet another finish than others:

Schiit WYRD USB Filter Review.psd.jpg

These solutions make "perfect" intuitive sense: USB is a computer port so by definition must have dirty power and signal. So why not clean them and generate better sound? Schiit doesn't provide any measurements to show efficacy of the product so that job falls on our shoulders.

For this testing I thought I should measure the performance of Schiit Modi 3 DAC per picture above. To cover our bases, I also tested with another DAC under review (March...

Review and Measurements of SMSL Sanskrit 10th DAC

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This is a review and detailed measurements of the SMSL Sanskrit 10th budget DAC. It retails for USD $100 on Amazon including shipping. I purchased mine (I think) from Massdrop at discount.

From pictures posted by SMSL, the unit looks like large plastic Lego pieces. Fortunately in person it looks quite a bit better:

SMSL Sanskrit 10th SK10 DAC Review.jpg

Remarkably at this price, the unit comes with a remote control. It also has three inputs: USB, S/PDIF and Toslink optical.

There is also a cute gimmick of the display rotating depending on whether you put it horizontal or vertical.

There are separate USB power inputs depending on whether you want to just use USB or S/PDIF. All my testing was done with the USB input jack.

If the performance is there, this would be quite a nice DAC to have. Let's see what the measurements show.

I powered the unit and hooked it up via USB and was greeted with this disappointing dashboard...

Review and Measurements of Gustard A20H DAC & AMP

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This is a review and detailed measurements of Gustard A20H DAC and headphone amplifier. It is on kind loan from a forum member. It retails for USD $850 on Amazon with free shipping (from China?). I am accelerating this review because it is on sale on massdrop for USD $700. Still not cheap but more reasonable.

For your extra money you get a much larger and beefier enclosure with a large LCD display:
Gustard 20H Dac and Headphone Amplifier Review.psd.jpg

I usually clean the units and touch them up in photoshop but in this case I choose to leave it alone so that you can see how well it shows smudges and scratches. Overall the enclosure is bland but OK.

Claim to fame of this unit is stepped attenuator implemented using a bunch of relays. The volume knob therefor is a rotary encoder telling the unit where to set the volume. And therein lies the main usability issue I found: if you rotate the knob quickly, it will change very slowly! This is of course the opposite of what you want. If...

Review and Measurements of Aurender A10 Streamer

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This is review and detailed measurements of the Aurender A10 streamer and player. It was kindly loaned to me for brief testing by Gig Harbor audio. The unit retails for USD $5,500. For that, you get a streamer and DAC with 4 TBytes of storage and SSD for caching.

If you are not familiar with Aurender, they are the most common streamer I see at audio shows. In that regard, its price is not a larger percentage of a high-end audio system but of course, significantly higher than the typical desktop products we talk about.

The unit I tested was quite hefty and had pretty high-end fit and finish. Please excuse the quality of the mobile phone picture in dim lighting:

aurender  A10 Music Server & Player.jpg

The unit I was testing kept complaining about the SSD needing repair due to improper shutdown but it allowed me to use it anyway. Was strange that it did not use some kind of journaling file system to allow quick recovery from a power failure.

For my testing, I was only interested in its...

Measurements of Parks Audio Puffin Phono Stage

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This is a measurement of Parks Audio DSP- based PUffin Phono amplifier. Yes, you read that right: it uses a DSP for implement RIAA curves and many, many other functions. It was kindly loaned to me in person to test our meet at friendly audio shop, Gig Harbor Audio. The unit retails for USD $399 including Prime shipping on Amazon.

Here is a quick shot of the unit while being tested with very dim light with my mobile phone:

Parks Audio Puffin Phono Stage DSP Review.jpg

The company is apparently well-known for its tube based phono stage. So imagine the shock and horror of its customer base when they heard that not only had he dispensed with tubes, but that the unit digitizes audio, processes it, and converts it back to analog. Sacrilegious! Quick search shows long threads of riots in street, folks feeling abandoned, going to psychiatrists and being asked about their childhood, etc.

Fortunately we are much more enlightened here...

Measurements of Nakamichi Dragon Cassette Deck

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This is a detail measurements of the iconic, Nakamichi Dragon Vintage cassette deck. It was kindly brought to me at a meet at our local audio store (Gig Harbor audio).

For those of you too young to know :), the Nakamichi Dragon has the reputation of being the best cassette deck available at the end of the cycle for the format. It came out in 1982 and retailed for USD $2,499. That would be $6,500 today's dollar so quite a lot of money. I was too poor to afford one at the time so it was a pleasure to get my hands on one finally for this test.

We were testing it in a dark room and this is just with the light of a phone so please forgive the poor lighting:

Nakamichi Dragon Cassette Tape Measurements.jpg

Unlike digital products and amplifiers, we are at the mercy of calibration tapes for testing such products. The owner had a few of them and that is what I used for testing.

I unfortunately did not capture the results of 1 kHz tone but here are some other frequencies.

315 Hz...

Review and Measurements of Audeze Deckard DAC and Amp

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This is a review and detailed measurements of Audeze Deckard DAC and headphone amplifier. It is on kind loan from a member and seems to be discontinued. Seems to be a product of year 2016 with retail price of USD $699. Owner has bought it used for much less.

The unit has rather unusual hefty metal enclosure with super sharp extruded aluminum edges that can easily pierce your fingers:

Audeze Deckard Headphone Amplifier and DAC Review.jpg

Other than that, the volume control feels very nice. There are RCA outputs and inputs in the back. The RCA out is variable and seems to just be connected to the output of the headphone amplifier. I only tested the unit as a DAC+Amp combo. With the front toggle switch, seems like you can use it as just a headphone amp/pre-amp if you wanted.

Looking for information on it, I ran into a CNET review saying this:


Is Steve Guttenberg right? Let's find out!

I adjusted the output to typical 2 volt...

Review: Apple vs Google USB-C Headphone Adapters

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This is a review, detailed measurements and comparison of Apple's USB-C adapter to the current and last version of Google Pixel headphone adapters. The Apple adapter costs just $9 including one day shipping for free. The Google dongle costs $12.

Not that any of these are large by any stretch but Apple's is also the smallest of the three:

Apple iPhone USB-C Headphone Adapter Audio Review.jpg

Oddly there is no apple logo or markings on the device. The others don't have it either but I thought Apple would insist on that.

All three adapters work in Windows with the appropriate adapter and that is how I tested them, allowing my analyzer to fully control and quantify their performance.

Format wise, Apple's supports the key ones:
Apple iPhone USB-C Headphone Adapter Audio Formats Supported.png

So very similar to Google Pixel V2 and better than V1 which only supported 48 kHz.

Note that volume control in Windows is active at all times even if you use WASAPI exclusive mode!

Not much else to talk about than getting into...

Study: Headphone Amp Gains: Low or High?

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This is an analysis of whether you are better off using low or high gain mode in a headphone amplifier in their overlapped region. Traditional rule of electronic design says there is no free lunch: higher gain means higher noise. While this has become the "conventional wisdom" and one that I routinely state myself, forum member asked if there is any hard data to back this. So I decided to test the theory on two headphone amplifiers: the Schiit Magni 3 and JDS Labs Atom.
Schiit Magni 3 Headphone Amp versus JDS Labs Atom Gain Review.jpg

The test matrix here is infinite in scope. What volume does one choose for each gain to test? After pondering for a second or two :), I decided to go the defensible route of setting low gain to max and then matching the same in high gain. Both of these amplifiers have analog volume controls and in high gain, they can be touchy as far as getting accurate levels out of them but I managed to get close enough.

Let's see what the measurements say.


Review: Battle of Schiit Audio DACs

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This is a review, detailed measurement and comparison of Schiit's Modi 2 (uber), Modi 2 Multibit and Modi 3. I have reviewed the Modi 2 uber and Modi 3 before so this is mostly focused on how the Modi Multibit compares to them. I have purchased all of them personally at different times. The Modi 2 Uber is now replaced by Modi 3 with the latter costing USD $99 plus shipping. The Schiit Multibit fetches quite a premium compared to that to the tune of USD $249 plus shipping. Is the extra cost worth it? This is what this review is about.

Starting from the top, Schiit seems to be playing with its design in each one of these units:

Schiit Modi Multibit Review Compared to Modi 3.jpg

Switch type, color and finish seem to vary some...

Review and Measurements of Audirect Beam and AQ Dragonfly

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This is a review, measurement, and detailed comparison of two "thumb drive" sized combo DAC and headphone amplifiers: the Audirect Beam and Audioquest Dragonfly Black. I had reviewed the latter last year but it was with my old measurement gear so I thought I perform a fresh set of data on it given the popularity of Dragonfly. I purchased the Audirect Beam from Amazon a few months ago for USD $104 (about $114 with tax). I purchased the AQ Dragonfly for USD $99 from Amazon just the same. The Audirect Beam is on sale for $80 on massdrop and hence the reason I thought I review it now just in case you want to take advantage of its sale.

The Audirect Beam is the smallest DAC+amp I have seen, sans the phone USB-C dongles:

Audirect Beam Portable DAC Review.jpg

It has a spring-loaded, nice feeling momentary rocker switch for turning the volume up or down. Sadly in practice it would not change level correctly, requiring multiple toggles.

The volume control changed the...

SMSL SU-8 Version 2 Balanced DAC

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This is an update to my previous review of SMSL SU-8. At a retail price of USD $212 on Amazon and balanced outputs, the SU-8 could provide a very compelling proposition. Unfortunately the performance of the balanced output in my first review sample was disappointing, showing significant switching noise. SMSL was kind enough to send me a second unit recently and I put it to test.

There is no functionality difference so see the previous review for details of that. Briefly here, you get a nice looking unit with a tiny display and remote control:
SMSL SU-8 DAC Version 2 Review.jpg

[the 44.1 kHz on the display is not showing all the way due to my camera shutter not being in sync with its refresh rate.]

Let's get into measurements and see how she performs.

Let's start with our unbalanced dashboard:
SMSL SU-8 DAC Version 2 Unbalanced Measurement.png

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