NOTE: this is an updated review of microRendu. Measurements were updated to use bitperfect path and max volume.
One of the latest trends in digital audio is to use a "streamer" device. This is something that sits between your music server on the home network, with then direct connection to the DAC. A lot of such devices have been built with Windows and Linux operating system on top of PC computer hardware. Sonore's microRendu is different in that it is built as an embedded, black box implementation.
This thread is about its measurements and not a full review. But briefly, this is a tiny device the size of a set of playing cards:
Both the packaging and aluminum enclosure scream "budget" equipment. So if you are getting this device as audiophile bling to impress your friends, this is not it.
The unit as mentioned, is a "bridge." It sits on the Ethernet network at one end and USB connection...
Here are measurements of the Entreq "signal grounding" box. If you don't know what that means, you are not alone . It is a type of device where you connect it to the ground or negative terminal of your audio signals and it is supposed to improve the fidelity of the system. I was kindly given a loan unit of Entreq Olympus Minimus for this testing by the company founder, "PO."
The box arrived a few weeks ago but have been too busy to test it until now. From the outside, it is a nicely made wooden box with a single terminal out back:
The box is very heavy so clearly filled with something substantial. I was not allowed to open the box so my evaluation is limited to measuring it.
I had thought of measuring a lot of things but once I got to it, the reality set in. The box has only one wire going to it, not two. That is, there is no return path for any electrical signal. Think of trying to test a...
Over the last few months I have had a number of requests to document my music server build. I finally got around to collecting and organizing my pictures and references.
There are a number of such efforts such as CA's "CAP" series of music server specs. I have read through them and much of what they do there doesn't make any sense to me and bring a ton of complexity. As an example is using a server-class motherboard, Windows Server OS which is expensive and very difficult to manage for ordinary users, expensive linear power supplies, etc.
The approach of then minimizing the tasks on the OS true third-party tools also doesn't make sense to me. From noise and jitter point of view, you want a chaotic/random activity. Removing all but a few system processes means both of these components can be become more correlated, predictable and hence potentially audible.
My goal in building my own server was much more down to earth:
1. 100% quiet. No fans. No spinning parts. Acoustic...
It seems intuitive that we would all have different tastes in sound reproduction. After all, there are thousands of different brands and models of speakers each with a different sound. Surely that is due to different people liking different sounds. Another fact that bolsters this intuition is that there is no reference for audio. So in that sense, there is no metric of accuracy either meaning it is a free for all, allowing anyone to pick any sound as being what they prefer.
Well, everything I just said is wrong! Turns out we are remarkably alike in what we prefer subjectively. We seem to have an internal compass that points to good sound and that when we only use that compass, we are able to determine what is proper and what is not. Dr. Toole in his book, Sound Reproduction, Loudspeakers and Rooms puts this most eloquently:
"Descriptors like pleasantness and preference must therefore be considered
as ranking in importance with accuracy and...
Really good talk/work by Bob Schulein, presented at Audio Engineering Society on how to determine an individual's dynamic range, and bandwidth that they can hear. There is a link to the files to be downloaded at the end. And summary results of the AES Chicago chapter.
Bob is a slow speaker so I watched it with no problem at 2x speed . Click on the gear and select the playback speed there.
Modern computing power has put in our hands incredibly powerful measurement tools. Prime example is Room EQ Wizard (REW), a free program which is an amazing toolbox of acoustic measurements. Alas, while computing power may be free enabling us to run such analysis that used to cost a lot of money in dedicated hardware, the fundamentals of what the tool measures must still be understood. Otherwise, it is exceedingly easy to arrive at the wrong data and worse yet, wrong conclusions about the science.
The purpose of this article is to demonstrate a key element: the relationship between time and frequency resolution. This is an underlying signal processing concept that is core to functionality of everything from audio and video to compression to how we measure room acoustics. Alas, while the concept is rather simple, it is not intuitive nor is it talked about much outside of the circle of industry researchers and professionals. Simply put, time and frequency resolution are enemies...
I first ran into this site when I was at Sony’s web site looking at their high-res music page. A link for content took me to ProStudioMasters. What I found was a delightful experience. Modern, interactive and fast user interface that easily leaves all of their competitors behind. When I am interacting with other sites, they feel like what music distribution looked before iTunes revolution. Primitive web sites, lousy payment methods, and all around ancient experience. What a breath of fresh air it was to land on ProStudioMasters and not see most of these issues. Let me dig in to show you why.
Here it is:
Modern, “web 2.0” interface that is a delight to look at, and highlights the album art nicely.
Hi everyone. This is my review of Roon media player. It is the highlights of what I find attractive in the software. As some of you know, my team was responsible for building the Windows Media Player which ships in every copy of Windows. Alas that software has been frozen in time for the last decade or so, and does not for a variety of reasons meet the needs of an audiophile or music lover. So with the build of my new server, I decided to go a new route.
I had tried JRiver a couple of years ago and immediately dismissed it. It is a huge piece of software and quite bloated in my view. I know it has immense set of features and I am not giving it a fair review in what I just said . Having managed the development of another complex player namely Windows Media Player, and seeing how hard it was to keep it reliable and performant, I have learned to heavily appreciate simplicity. I don’t need or want video playback for example. What I need is something that doesn’t...
I hope you are not getting tired of jitter talk because I have more info to share .
One of the common arguments made against jitter mattering is that: "the data is buffered and clock regenerated in the DAC so jitter won't be there." This makes all the sense in the world. Once we capture the data and then push it out at our will, there shouldn't be a problem. Well, there is a problem. A serious one. Buffering and clock regeneration do not deal with jitter by themselves. I have explained this in words many times but this time I am bringing in some specific data to hopefully put this myth to bed (yeh, wishful thinking ).
The way a clock is "regenerated" is to have a local oscillator (clock) that we can change its frequency to eventually match and track the incoming digital stream. As you may know, S/PDIF is a serial digital connection with clock and data intermixed. By using this circuit which is called a Phase Locked Loop (or PLL for short), we are...
This is an article I wrote for Widescreen Review Magazine a few months ago.
Inside Your AVR
Do you know what is inside your electronics? What is a DSP? The output stage? Power supply? FPGA? ASIC? Do these terms have any meaning? I suspect for many of you these are obscure terms. Yet, pick up the brochure for any audio/video product and such buzzwords abound. While it is impossible to convey the true nature of these technologies in an article like this, I think we can become more educated and at least have some high level understanding of what goes on inside your electronics. For this article, I am going to open the top of a premium AVR I purchased back in 2007. At the risk of stating the obvious, you are not going to become a design engineer from reading this one article. But rather, get you started on a journey to know more about what is under the hood and what type of design trade off a manufacturer may make. I hope to do...