Two years have passed since version three CAPS servers were announced. Over this period of time many of the server parts went out of production, leading to CAPS lookalikes. I am happy to see people coming up with their own solutions to the lack of parts problem. Unfortunately people's CAPS servers move further apart from a similar design. This fragmentation can increase troubleshooting time and compatibility with the many third party software and hardware solutions the CA Community is now using. Addressing the issue of parts unavailability is difficult, if not impossible, without ordering massive quantities of items like motherboards, hard drives, and RAM. In the CAPS v4 designs I've addressed the issue with parts that have long term support and parts from well established companies when possible. In addition, I'd like the CA Community to look at the CAPS designs as part formula and part platform from which to build the worlds best music servers. Readers who just want a formula for successful playback can build or order a CAPS server and be happily playing music with the knowledge their servers are very good and will last a relatively long time. On the other hand, the CA Community has grown and knowledge about music servers has increased greatly since the first few CAPS designs were published. Because of this, I'd like those in the CA Community with imaginations and skills to consider CAPS v4 a platform from which to expand and perfect their very own server. As long as the foundation is a CAPS design and the individual changes aren't too drastic, we'll avoid the fragmentation of the PC world at large. For the first time members of the CA Community will have the opportunity to submit their CAPS designs for full CA Community endorsement and the right to attach their own names as a suffix to the CAPS "platform" server from which the design was created. I'll start us off with my four CAPS v4 designs and let the CA Community take them to new heights. This is a great opportunity to use the collective knowledge of the global CA Community to further this wonderful hobby of ours.
A Note About Sponsorship
Before going further I'd like to thank JRiver for sponsoring the entire CAPS v4 project. Researching and purchasing all the parts for CAPS servers takes time and money. In the past I spent over $10,000 just trying different motherboards, memory, SSDs, cases, etc… This time around I thought it would be prudent and a win-win for everybody if I obtained sponsorship for CAPS v4. I sought sponsorship from a handfull of companies and before the "ink" on the email was dry JRiver stepped up to sponsor the whole project. This sponsorship enabled me to take the CAPS project further in a shorter period of time than I would have been able to on my own. The bottom line is that members of the CA Community benefitted from this sponsorship. Without this benefit to the entire Community I wouldn't have sought sponsorship. Period. Also, JRiver had no input on the design of the servers' hardware or software. Prior to contacting JRiver I had already decided what playback applications would be used for the CAPS v4 project. I also didn't let JRiver know this software decision, thus avoiding any semblance of impropriety. Again, thanks to JRiver for supporting CAPS v4 and the CA Community.
CAPS - Computer Audiophile Pocket Server
As usual I should address the reasoning behind the CAPS name. Here is what I wrote two years ago. There is no need to make any changes as the reason hasn't changed.
"New CA readers may be asking if the CAPS v3 servers can really squeeze into a pocket or if I've use my creative liberty too liberally when naming the servers. The following quote from the CAPS v1 article comments will hopefully answer questions related to the name. "The title does not reference the literal size of the music server. The name Pocket Server is no less accurate than the name Compact Car. Along the way this server was named the Pocket Server by a colleague who was very surprise at its small size when I pulled it out of my carry-on luggage. The server is a bit larger today than it was at that time but the name hasn't changed. This colleague named the server because it was so small not because it actually fits into a pocket. I elected to keep the name, going with the spirit of the name not the letter of the name." Near the end of CAPS v3 testing I received the new Intel Next Unit of Computing (NUC). This small computer does fit into a large pocket but thus far I don't see a reason to use it in a CAPS design. The NUC doesn't meet the requirement of a fanless design. Plus, there's no way I would select a retail packaged computer that only requires RAM and a hard drive and call it a CAPS design."
In addition to reasoning above, I mentioned the Intel NUC in my paragraph from CAPS version three. It's funny how times change. CAPS v4 features two servers that are based on the Intel NUC platform! One has a new custom USB board created specifically for this server and the other uses all external solutions to high end computer audio issues such as USB and power.
Goals and Requirements
My goals and requirements for the CAPS v4 project differ from the first three projects. My main goal of CAPS v4 is to provide a formula or platform for great sound. The advancement of the CA Community, online companies who build and sell CAPS servers, and the changing needs of computer audiophile's had a major impact on my requirements. The reasons for changing the requirements are many and I will address each one below.
List of requirements from CAPS v1 through v3 with comments about v4.
- Absolutely silent. - Three of the four v4 servers are silent. The non-silent server is designed to go outside the listening room, negating the silent requirement.
- Capable of great sound.
- Great looking. - This is too subjective and doesn't really matter for one of the v4 servers as it will not reside near the audio components.
- No moving parts. - The CAPS v4 project features three fanless servers and one server with fans and spinning hard drives. The server with fans and HDDs isn't designed for a listening room and thus doesn't require a quiet environment.
- Fairly inexpensive.
- No legacy components.
- Easy to operate.
- Directly or
- Easy to assemble / install
- Assembly / installation by one's self or
- Assembly / installation by local computer shop, son, daughter, neighbor, or friend.
- Small size. - This requirement is too relative and subjective. One of the v4 servers is housed in a mid sized tower chassis that isn't meant for the listening environment. The other servers range from small to full "a/v component" size.
- Low power consumption. - The most required feature of the last few CAPS designs was more power. Thus, I have removed the low power requirement because more processing power equates to more power consumption. Fortunately none of the servers in the v4 project have high power consumption.
- Low heat.
- Accept an add-in card for audio or additional capabilities. Hardware & Software must accept appropriate add-in cards.
- Play 16/44.1, 24/44.1, 24/88.2, 24/96, 24/176.4, 24/192 and DSD all bit perfect.
CAPS v4 Hardware Brief
CAPS v4 Cortes - This server is a response to computer audiophiles' changing playback methods and the addition of many more network based players. Cortes is a Windows based Network Attached Storage (NAS) replacement. Members of the CA Community no longer have to wait for NAS enabled versions of their favorite software. Running Windows enables installation of almost any audio application and additional diagnostic tools. Cortes runs JRiver Media Center out of the box and can take advantage of all the UPnP / DLNA capabilities of JRMC. I've been running a Cortes server for months with JRMC, MinimServer, Devialet AIR, TIDAL, Sonos, Logitech Media Server, Twonky, and UPnP Tools without a single issue. This server is as stable as a Linux based NAS, but endlessly more flexible.
CAPS v4 Pipeline - This is a more traditional CAPS server in that it can connect directly to one's audio system. The chassis is similar to a full size A/V component. This enables use of a number of audio cards (AES, S/PDIF, etc..) or USB cards. The chassis has room for add-on cards, power filters, power supplies, and more. The motherboard has a minimum seven year life. I've been using this server with a linear power supply and it has been rock solid. I believe this server has the most potential for derivative designs and to be pushed to the max for sound quality.
CAPS v4 Maroubra - This is an Intel NUC based server in a fanless chassis. It has a custom USB card designed specifically of this server, wireless capability, and a surprising amount of internal storage.
CAPS v4 Bundoran - This is also an Intel NUC based server in a fanless chassis. The main difference between this and the Pipeline server is that Bundoran uses external USB power "conditioning", enabling users to experiment and even bypass this feature when using a DAC that is immune to external power such as the Ayre Acoustics QB-9 DSD.
CAPS v4 Software
All four CAPS servers will run Windows 8.1 Professional 64-bit and JRiver Media Center v20. At this point in time Windows 8.1 is the only stable game in town that's compatible with any number of applications and audio components. I'm excited to see what members of the CA Community will do when they install Linux, but for now my four main designs are Windows based. I selected JRiver Media Center v20 because it's very stable, has great support, is widely used in the CA Community, and is capable of great sound quality for all PCM and DSD sample rates as well as multi-channel audio. There are other applications available that I consider a bit more fringe at this moment in time. I'll leave it to the CA Community to use and tweak those applications and share results with everyone. As a formula and platform I believe Windows 8.1 Professional and JRiver Media Center v20 is the best combination.
A Bit About Derivative Designs
As I mentioned in the opening paragraph, members of the CA Community can come up with derivative designs based on any of the four CAPS v4 servers and submit them for CA endorsement. A derivative server based on the Pipeline design would be called CAPS v4 Pipeline (Name of your choice here). I am very excited to see what users from around the world come up with and submit for endorsement. There aren't hard and fast rules for endorsement, but the server should be derived from one of the four CAPS v4 servers, be very stable unless noted as a bleeding edge design, and meet most of the CAPS requirements. It's not a requirement to ship hardware to CA for endorsement. We will use the forums to discuss current and proposed CAPS derivatives. Servers be endorsed by the entire CA Community.
In the coming weeks I will release individual articles for each CAPS v4 servers. These articles will detail the hardware I selected and my reasons for selecting each component. I hope everyone is as excited as I am. It's CAPS season!