Articles, Reviews and Measurements of Audio Products

This is a review, detailed measurements and listening tests of Focal Clear Pro headphone. It is on kind loan from a member and costs US $1499.

As our British friends say, the Clear Pro "looks the part." It a unique and luxurious design. Comfort was very good although the cups are on the smaller size. The headband spring is quite progressive and gets stiff fast. So if you have a wider head, it may not be so easy to ear.

The standard cord supplied with it is rather thick, short and kind of stiff. Not a fan.

The measurements you are about to see are made using a standardized Gras 45C. Please note that headphone measurements are not very exact so variations exist between reviewers especially in higher frequencies.

Edit: I was told the headphone was the "MG" version. It is...

This is a review and detailed measurements of the AOSHIDA SMSL C200 balanced DAC and headphone amplifier. It costs US $210.

The unit looks attractive enough for a desktop product. The LED is function but sadly displays the sample rate rather than volume (until you change that). Navigating the menus is a bit hard but the included remote helps some. It is very nice to see built-in power supply:



As well as balanced output in the form of TRS outputs.

SMSL C200 DAC Measurements
I expect excellent performance from SMSL and it delivers:


[ATTACH type="full" alt="SMSL C200 Balanced DAC and Headphone Amplifier...

I keep getting asked to address the paper by professor Kunchur on his latest paper as promoted by a number of youtubers. There, he claims to have found correlated measurements for why different cable "grades" make an audible difference. So I put together a presentation detailing his testing and problems with it:


It is long (41 minutes) but hopefully you can skim through it. If not, you have for reference next time someone throws the paper/youtube video at you.

Edit: link to the paper: http://boson.physics.sc.edu/~kunchur/papers/Interconnect-cable-measurements--Kunchur.pdf

Claim
A claim is frequently made that DAC digital filters with a lot of taps can make a significant difference in sound quality. Some software packages and even hardware manufacturers are touting the benefits of large FIR filters, often with millions of taps, supposedly because these produce a more natural, smoother, analog sound or improve "time domain" accuracy, whatever that means. Some of these are sold at large premiums, supposedly because of the complexity of implementing large filters.

Test
Let's use DeltaWave software to find out the real story. I'll use a null test to produce a difference between a music file generated with two different size filters, and then measure the differences in frequency and time domain. For audibility testing, we'll also listen to it. Let's see if there's something to these claims!

The music file I'll be using is one some you may recognize as one used in other null...

Video review of my recently reviewed Chord Hugo TT2 DAC:


Not much new information although you get my nuances of how I feel about the product and its performance.

This is a review, detailed measurements and listening tests of Chord Hugo TT2 DAC and amplifier. It is on kind loan from a member and costs US $6,725.

The product looks and feels like it was designed by a committee with multiple design styles from globes to dot matrix green (!) display. Labels are almost impossible to read as you see in the front (much harder when looking from above). The aforementioned green display has a line going through it courtesy of the smoked cover's right angle. So most of the time it cuts off what it is showing. There is a long delay as the unit powers up, supposedly charging its supercaps. Mode changes from low to high gain trigger the same 10 to 15 second pause. Same with when plugging and unplugging the headphone. Confusing light show goes on during all of this.

Fortunately a remote control is provided which while very cheap looking, performs most...

This is a review and detailed measurements of the Adam A4V studio monitor (active DSP speaker). I purchased it new for US $500.

The look is standard ADAM Audio which is not bad. The build seems rather solid but with very sharp corners past the front face. Back panel shows clearly UI for changing things:



The momentary switches are easier to manipulate than competing dip switches. There are three "voicing" options. Pure which is anechoic/flat response. UHR which is Adam's own target and "Ext" which is custom. You program that using Ethernet port. I tried to do that only to find out the software won't be ready until next month.

Level of tweeter hiss is very low and not a concern for me anyway.

Here are the specifications:


Measurements that you are about to see were performed using the...

This is a review and detailed measurements of the JBL Synthesis SDR-35 Audio/Video Receiver with 16 channels of processing with class G amplification and support for Dirac Room EQ. It is on kind loan from a member and costs US $8,250.

The unit looks elegant and user interface is simple to operate using the large LCD on the left. Back panel shows the usual connections including too many analog inputs:


This unit was upgraded with the latest HDMI board and certified to be working correctly.

There are three fans but I don't think any of them came on. Internal amplifier fins are step above "spring steel" of cheap AVRs with extruded but thin aluminum. Class G operation of amplifiers keeps the unit from getting overly hot.

There is a ton to measure here, taking me almost two days to work through them. A quirk of the unit caused fair bit of delay. When it goes into protection -- which it goes into instead of...

The latest version of FireFox with DuckDuckGo has a bug when browsing certain pages here. It will error out with redirection message. Fortunately there is a quick fix. While browsing our forum, simply pull up the options and disable "Site Privacy Protection."



Please report the problem to DuckDuckGo. They need to investigate why this is happening as it is random and at their end. If they respond and say the problem is ours, please let me know.

This is a review and detailed measurements of the FiiO BTR7 portable battery operated USB & Bluetooth DAC and THX balanced headphone amplifier. It is on kind loan from a member and costs US $199.99.

A bright, high contrast IPS LCD greets you with lovely/star-trek style fonts which I liked very much. I was also happy to see detailed information about the bit rate (24 "Bits" above). I would have wanted a larger volume level though. And acceleration in the volume control:


The rocker up/down volume control provides much finer level adjustment than that built into the operating system which was nice. On the left there is a very useful button to tell the unit to charge or not over USB input, eliminating having to have two such connectors:


The companion Bluetooth app provides nice control of the unit including the ability to "boost" the balanced output by fair bit. Alas, choice...