This article discusses elements of digital audio including a detailed description of my current digital audio 2 channel stereo system illustrating how anyone can assemble a high performance affordable digital audio system.
I am by nature an early adopter. Which means I’ll try certain types of technology and audio gear, mostly out of curiosity, long before it becomes mainstream. So it was that almost 10 years ago I got started on my journey into “digital audio”. While I don’t consider myself an expert on the subject, over time I’ve evolved a digital audio system that works incredibly well and delivers really great sound using a combination of mostly inexpensive hardware and mostly free (open source) software.
What Is Digital Audio?
It’s been called digital audio, computer audio, or personal audio. Regardless of what you call it, it’s the conversion, curation, storage, access and playing of music in a digital format using a personal computer and/or server. With digital audio, the computer becomes the storage medium, the transport/delivery device, and either directly or indirectly, the man-machine control interface for managing and playing the stored music.
But aren’t CD’s already digital media you ask? Yes, but digital (computer) audio is about moving beyond the physical media of disks and working with music stored as files on a hard drive.
As digital audio has grown in popularity, CD’s and CD player have waned. I don’t think it’s an exaggeration to say that CD’s will eventually all but disappear over time. I’ve literally not played a physical CD at home in several years now. The only CD player I own these days is in my car or on my desktop computer. Neither get used to play music.
Rise of The Computer Audiophile
Digital Audio is now an established and growing subset of the audiophile world. Even as the vinyl resurgence continues to accelerate on the analog side, digital audio is arguably where all the cool innovation and growth is happening.
A central focus of digital audio growth is the now ubiquitous DAC (digital to analog converter) which converts the world of digital bits and sampling rates over to the analog world of voltage signals that ultimately gets amplified (increased in voltage level) so we can hear the music. Whereas DACs were always embedded inside each CD player you’ve owned, the DAC has come into its own as perhaps the most critical part of a high performance digital audio system. Concurrent with the growth in DACs is the increasing availability of full (16bit/44kHz, a.k.a. “red book”) and higher (24bit/96kHz) resolution audio files for direct purchase and download.
Prior to digital audio, being an audiophile offered 2 overlapping hobbies (obsessions?): music and analog audio gear. With the advent of digital audio, you can now add the 3rd hobby of personal computers into the mix. For the passionate audiophile, digital audio provides nothing less than an exponential increase in opportunities to argue over what sounds better not to mention a whole new generation of add-on products and tweaks ranging from the ridiculous to the awesome. Digital audio for audiophiles even has its own home on the internet – Computer Audiophile. Such fun!
RIP’n, FLAC’n and Download’n
Being an audiophile I’m going to unapologetically snob-up and dismiss dumbed down lossy mp3 files. For me, FLAC (Free Lossless Audio Codec) is the only way to go. The key thing with FLAC is it uses lossless compression. Done right, ripping your original CD to compressed FLAC yields a bit perfect copy of the original music. A FLAC file takes up less space (than an uncompressed WAV file) without sacrificing sound quality. Also, unlike a WAV file, FLAC files can hold all the essential metadata about the artist, album title, track title etc. FLAC is also open source so no company is going to hold the fate of your music collection in their hands or charge you to use it. FLAC is simply great. Go with FLAC.
While there are many software applications that can rip your CDs to FLAC, I strongly recommend Exact Audio Copy (EAC). Yes, it’s a bit nerdy and not the slickest or easiest to use. However, EAC is considered the best ripping tool out there if …well…”exact audio copy” is your goal.
Here comes the bad news. If you have a large existing collection of CD and want to go digital audio you have a TON of work ahead of you.
Let’s say you’ve accumulated 1,000 CDs. Assume it takes 5 minutes on average to properly rip a CD. Here’s the math. 5 min/CD x 1000 CD = 5,000 minutes. 5,000 min / 60 min/hr = 83.3 hours. Now let’s further assume you’re only going to do this for 2 hours non-stop per session each day. So that’s 83.3 days / 2 hours/day = ~42 days. In reality it will take longer because you’re not a machine and you’ll make mistakes, you’ll get distracted, and you’ll get bored. Plus you won’t do it every single day, you just won’t. Just assume it will take you several months. My advice is don’t think about it too much. Just get started.
It took me the better part of year to get all of my CDs ripped to hard drives. When I was done I put every CD into a few large 3-ring storage “flipper” binders along with their artwork inserts and tossed out every single plastic case. The binders all fit on about 3 linear foot of shelf space. Very satisfying. Every few months I dust the binders (not really). I don’t ever look at the CDs anymore. (really).
Which brings us to the best solution to avoid RIP’n going forward. Stop buying CDs. There are now several websites selling full and higher resolution FLAC files. While there are others, one notable site is HD Tracks. Why RIP when you can download! Alternatively you can also stream but that’s a topic for another day. Personally I’m still wedded to the idea of music ownership yet I can foresee a time in the future when rent-to-play streaming may well become the dominant model.
Thou Shalt Back Up
Once you cut the physical media CD chord you need a rock solid strategy for ensuring you will never lose your music files to a crashed operating system or hard drive failure. I practice a layered approach to backing up my music files.
First, I never keep my data files (including music) on the same hard drive (or solid state drive) as my operating system. If my OS crashes and burns, too bad so sad but at least my data resides elsewhere and won’t disappear at the same time. I highly recommend getting a separate drive for you data and music files. In fact I have 2 additional drives on my primary computer, one for non-music data, and one for music only.
Second, you need a backup drive to your primary music/data drive. I have a second computer that I use as a dedicated music server and backup to my primary office computer. Anything music that I add to my primary computer automatically gets copied over to the music server which is located elsewhere in the building.
I confess that I’m not entirely satisfied with this arrangement for one simple reason. Should the building burn down, my entire collection of music could literally go up in smoke including the original CDs. To mitigate this risk, I run a separate backup to a portable hard drive every few weeks which I then store offsite. Another option is to simply upload the entire collection to the cloud. While I do that will all my personal and work file I don’t do it with my music files. Why? Because I have almost a 1 TB of music and I’m too cheap to buy the extra cloud storage. That may change soon enough (not the being cheap part) given the ongoing decline is cloud storage pricing.
My Digital Audio System
So how to put all of this together with my stereo system? Behold the info-graphic.
While not exhaustively detailed, the info-graphic below does a decent job of laying out the key elements of my digital audio system as of Q1 2016. The big picture is I have two separate systems that are linked wirelessly. My main music system is located in the living room area where I keep my good 2 channel stereo system and music server (PC). This is my listening room if you will. My second system is located in an office where all the engineering development work is done for Tortuga Audio. The rest of this article elaborates on this info-graphic.
The main workstation is a high performance PC running Windows 10 (painless free upgrade from 8.1) that is connected to the internet via a cable modem and router. This is where I manage my digital music collection which now occupies just shy of 1TB of hard drive storage space. This PC is used almost exclusively for engineering and business but also serves as a main storage for ripped and downloaded music files. It’s connected to a small stereo system used for audio product development and testing.
This PC has 3 storage devices. A solid state drive that runs the OS and applications, a hard drive for music, and a second hard drive that hold all other non-music data. I currently use J. River Media Center (JRMC) for managing and playing digital music locally. I’ve tried other players but JRMC is a truly excellent player with endless options and features. If anything JRMC may be too much for the casual user but I love the visual interface and controls and ability to quickly organize and update files.
I use a backup software application called GoodSync which I also highly recommend. Goodsync periodically backs up everything on the main workstation to a PC in my living room that we’ll call the music server. This backup is done wirelessly. Everything except my music files are also copied to my Google Drive in the cloud.
The music server PC is a relatively low powered and inexpensive PC running Windows 10. It’s connected to the internet/router via WiFi and receives updated files from the Main Workstation via the GoodSync application. In addition to serving up music files to my 2 channel stereo system, it also provides backup data storage for my main workstation.
By far the coolest part of this digital music system is the music server itself together with the music player and the app used to control it all via remote control.
The server application is Logitech Media Server (“LMS”) which runs on the server PC. LMS is essentially the Squeezebox network music player originally developed by Slim Devices. They later sold Squeezebox™ to the Logitech® which ultimately discontinued the product around 2011 to the disappointment of many. Though discontinued by Logitech, LMS itself remains alive and well within the open source community and is a highly evolved and stable server. The last incarnation of LMS can be found here. Oh, and it’s free!
While LMS organizes and serves up digital music files, it requires a “player” application to actually play the music files on the server. I use an application called Squeezelite. Squeezelite is a software based player that does the same thing that the original Squeezebox, Squeezebox Duet and later Squeezebox Touch hardware based players did. It’s also free!
The final piece of the music server/player puzzle is an IOS app called iPeng. iPeng (version 9) is an excellent music remote app developed for Logitech® Squeezebox™ and compatible music players. iPeng communicates directly with the Squeezelite player via the wireless access point connected to the music server PC. iPeng is not free but at ~$10 it’s a steal.
With iPeng running on my iPad I’m able to sit comfortably on my couch while perusing my music collection via iPeng and select music files to play through my stereo. My stereo rig includes a miniDSP, a DAC, a Tortuga Audio passive preamp, a pair of mono amps, and a pair of full range speakers where both the amps and speakers are Tortuga Audio prototypes.
I like vinyl and analog too but digital audio is just way cooler to mess with. It all works seamlessly and sounds great!
Nice, but I just eliminate all that by streaming anything I ever owned and millions more on high res Tidal.
Why be bothered with the physical media ?
I agree that high rez streaming will eventually overtake physical media for the majority. However, there will always be folks who prefer to “own” the music. While not coldly rational, it’s quite human for people to collect and own things they’re interested in. When I’m gone I doubt either of my daughters will make use of my 2 GB drive full of FLAC files even though they’re both avid music fans.
I received a rather cranky email from a reader who took issue with my statement that WAV files don’t hold metadata. Apparently metadata can indeed be embedded into WAV files but for various technical, commercial and/or historical reasons this practice never became standardized or automatic as part of ripping from CDs to WAV files. Yes, you can do it if you get the right software and stuff it in there yourself. Point given to cranky emailer. However, with conversion to FLAC files the metadata comes along for the ride as a matter of course. No further fussing required in most cases. Point given to FLAC. Two points in fact. FLAC wins!
Did you mention fanless music server and linear power supply? These are two major ingredients in getting the better SQ and quiet operation. However, there has been development of switching PSU that offers as good or superior performance.
My own experience with very small switching PSU voltage regulators has shown that a well designed switch PSU can be every bit as quiet and rock solid as a linear. I know that most PSU’s for PC/server are notoriously noisy. The PC I use for my music server is fanless. I don’t think you need the hottest high clock speed CPU to run a music server so no need for forced cooling.
Morten, thanks for sharing the joy of computer audio. I just wanted to add my two cents: ripping a CD in 5 minutes is not going to give you full benefit of high quality music files. Instead, do it as slowly as you could (1x or 2x copying speed), take a listen, and tell me which you prefer, the faster ripping or the slower copying.
Point taken. I’ve gone with the more or less default settings of EAC with acceptable results. I’ve not tried to prove to myself that it was in fact bit perfect copying but many have done so and have reported excellent results. On the other hand even at fast ripping speeds it’s molasses in January compared to real time by a CD transport. ????
Beside EAC I’m also using dBpoweramp to rip CDs in Ultra Secure mode. Trust me, when done right, ripped files can rival top shelf CD transport. Depth, rich tonality, details, black background, you name it, they are all there. Extra ripping time pays off, you will be rewarded abundantly. I beg you to try at least one CD, even one track. Or, if you and I both have the same CD, I’d be happy to slow rip and Dropbox you the same tracks for you to compare.