Article: C.A.P.S. v2.0

[1audio]

There are a number of cards available that go from PCIe to USB3(+2+1). None are "audiophile" grade, certainly not yet, but they are simple and cheap. You would probably still get some benefit from the added USB interface. If you were handy they could be modified with improved caps, power etc. but its not simple. I will make sure we note the PCI/PCIexpress issue since its has large potential confusion built in (there is also a PCIx bus, a 64 bit PCI bus). The PCI bus is considered to be obsolete but still is very useful.<br />

<br />

[TimDH]

Hi Demian,<br />

<br />

I appreciate your no-nonsense postings in this forum. I have to say that the digital world is surprisingly hard to figure out for a rationalist like me who would like to think that digital is digital, but respects people who measure and find that it's not so simple. My question, which may be hard for you to answer: do the issues solved by filtering the hard drives and fans apply to all digital interfaces, more or less? I'm contemplating going to Peter St's DAC, after building my own PC, that uses the Juli@ PCI interface. I'm happy to put filtering in line before the sound goes out, but it'd be good to know whether the noise reduction you show in your web pages would apply to the Juli@ interface too? Thanks a lot in advance...<br />

<br />

Tim

[Quest]

Well, the very last option is to use a PCI to PCIe adapter if it is really that ideal..

[vortecjr]

What USB device are you planning on using?<br />

<br />

Jesus R<br />

www.sonore.us

[1audio]

Tim:<br />

PeterST's DAC project is really ambitious and he has put a lot of thought into solving many problems. I don't think there is anyplace on his external module that would even accept a packaged filter like the the SoTM filters. I believe he has pretty extensive power management and regulation in the DAC module. <br />

<br />

However the host computer would benefit from the filtering on SATA and Fan connections (if you need a fan). At a higher level you want to reduce noise at its source. Shielding noise sensitive stuff is important and necessary but the radiating noise source causes more problems and degradation and is best dealt with at the source. Its also better to design/plan for low noise that to try to reduce it later. That suggests using lower power components, with just enough power to do what you need done, since lower power means less noise.<br />

<br />

[89reksal]

Hi all,<br />

I've been trying to read up as much as I can on this site with the goal of building my own CAPS type server. It's a fantastic site with an incredible amount of information to absorb. I had been waiting until the new CAP 2 was published before starting my build.<br />

I have to say it's thrown me for a bit of a loop since I had been assuming I would be running S/PDIF digital RCA out from the server into my Bryston BP25DA (preamp with built in dac which has only RCA digital inputs).<br />

This new CAPS 2 server is based on no sound card and USB outut to dac which leads to many questions for me. <br />

First off, is USB sound out as implemented in CAPS2 "better" sonically then what would obtained from using digital out from a sound card such as the Juli@, Lynx or ASUS Sonar Essence? <br />

If yes, would it be worth while for me to use the CAPS 2 as spec'd, and then use a USB to S/PDIF converter such as the Halide Bridge to feed my dac digital input?<br />

If USB is not "better" then the digital out via sound card option, then would I be able to add a PCI sound card to the CAPS 2 and get my digital sound outout to my dac this way? Would the spec'd 60 W power supply run the additional sound card or would something else be needed?<br />

There's also quite a cost difference in using USB out as spec'd which would require the $339 PCI to USB card plus the Halide bridge for $450, compared to using a sound card, where even using a Lynx card would still come in cheaper.<br />

I'm sure there's many things I'm not taking into account yet but I would very much appreciate any suggestions or feedback.<br />

I'm sure there are many others in a similar situation with a dac with no USB input. Hopefully answers to my post will be helpful for them as well.<br />

Thanks in advance for your help and thanks as well for a great site and place to be able to learn about this topic.<br />

<br />

Bill

[Quest]

Plan to use this with the Chord QBD 76 HD DAC which has async usb input.<br />

<br />

I already have a fanless hfx classic PC based on a i5.. just looking to maximise the performance. I think I can use a PCI to PCIe adapter to use the SOTM tx-USB but as with all adapters, will have to accept a slight drop in performance probably.

[Quest]

Breaking this up into a few answers for you:<br />

<br />

1. USB sound out in CAPS2 should theoretically sound better than a generic soundcard (not the really expensive ones) just because of further isolation. My own experience is that Lynx sounds better than first gen usb/spdif converters but not second gen like the Wavelink. Furthermore, it is difficult to get the right cabling done up (or AB comparison) for Lynx due to the connectors.<br />

<br />

2. Regardless whether you go Lynx OR usb/spdif converter, the CAPS2 should make an improvement. Moving to fanless PC for me already gave quite abit better sound even though I was using a async usb dac.<br />

<br />

3. You don't have to copy Chris's build entirely. I don't think many readers have experience with things like the USB card to be able to quantify the difference (I'm trying to fit one in though I do not have PCI), so just go with what you feel is right. Either way am sure if you follow general guidelines you will get 90% of the way there.<br />

<br />

IMO the most critical things to get right in the PC:<br />

- Power supply, power cord, power distributor<br />

- Going fanless, SSD. Using the right usb slot if using motherboard.<br />

- Software

[vortecjr]

I was going to send you something left over from an R&D project to try out, but it will not work with that DAC. I might have something else, but I need to look into it. I'll let you know if I find it.<br />

<br />

Jesus R<br />

www.sonore.us

[JR_Audio]

Hi Chris<br />

<br />

Thank you for the C.A.P.S. 2 article. Nice one, with some audiophile tweeks. Also for mentioning BitRemote as an alternative to RiverMote.<br />

<br />

Juergen

[Audio_ELF]

Hey folks.. While it's great to discuss alternative recipes for servers; remember anything outside of Chris's suggested items is no longer a CAPSv2 server so (IMHO) some of this discussion would be best taken into new threads - especially any discussion off topic from commercial entities. I'm not sure anyone has broken the rules (in spirit or technicality) but some posts (IMO) have headed that way. <br />

<br />

Eloise

[Bob D]

Chris,<br />

<br />

Thanks for your creativity in advancing high performance and affordable music servers. <br />

<br />

I have a few comments and questions...<br />

<br />

In addition to your design requirements, I have need for HDMI and firewire for use with my Weiss DAC202. I'm considering the ASUS http://usa.asus.com/Motherboards/Intel_CPU_on_Board/AT5IONTI/ motherboard given it has HDMI. In addition, it does support USB 3.0 which may offer a very fast means to deliver music data files to the server via USB 3.0 external drive(s). <br />

<br />

Here are my questions:<br />

1) Would using the motherboard USB ports attached to external USB disk storage compromise the spirit of your overall design basis? If so, how?<br />

2) Would you suggest using perhaps a second SOtM power filter and external power supply on the external USB drives assuming the voltage rails are within operating tolerances of the drives? Currently I do have the AC-side of my USB external drive power supply plugged into my PS audio Power Plant. I'm not certain if the power supply noise is introduced during the AC rectification process or is simply noise from the originating AC. I don't know if the the idea of filtering the Power on the USB drives is necessary. Your thoughts?<br />

3) Where in the M10 case did you mount the SOtM?<br />

4) What brand and model of a Firewire card would you suggest for the ASUS PCIe slot?<br />

5) What didn't I ask that I should have?<br />

<br />

Thanks Chris.<br />

<br />

<br />

[Valvefan]

Hi Qwest,<br />

<br />

Who makes a PCI to PCIe adaptor? My MB has only a PCIe slot. Can I use the SoTM USB card?<br />

<br />

Valvefan

[vortecjr]

FYI: SOtM advised me today that not all PCI to PCIe adaptors are compatible. I looked just for kicks today and didn't find any, but it was just a quick search. Either way SOtM is looking into making a PCIe version as well....<br />

<br />

Jesus R<br />

www.sonore.us

[freddie40]

1) They wanted it to be absolutely silent: I consider the Mac Mini to be that if you have a SSD.<br />

<br />

2) Capable of Great sound: I consider the Mac Mini to be that.<br />

<br />

3) Great looking: I consider the Mac Mini to be that.<br />

<br />

4) No moving parts. If you replace the hard drive with a SSD then it doesn't. Their machine does not have a DVD so the Mac Mini wins.<br />

<br />

5) Fairly inexpensive. The C. A. P. S. v2.0 is more than $1400 and only has 4GB of RAM. The MAC mini wins on this.<br />

<br />

All of the rest are the same.<br />

<br />

Except for the USB interface and the Power Supply the C. A. P. S. v2.0 is nothing real special. The processor is slower (1.8 GHZ), less RAM (4GB Maxed out).<br />

<br />

So, a stock Mac Mini with a SSD drive and 8GB of RAM is about $900.<br />

<br />

The C. A. P. S. v2.0 with a slower processor, 4GB of RAM and runs Windows is more than $1400.<br />

<br />

Does the USB and Power supply make up for the slower processor and less RAM? I guess I would call it a draw.<br />

<br />

Therefore you would go by price, the Mac Wins <br />

<br />

Dave (A Happy Mac Mini User)

[Quest]

PCI to PCIe adapters are indeed available. Since I am in Asia I wrote to SOTM about it before and they recommended me this:<br />

http://www.carpckorea.com/front/php/product.php?product%20no=4881&main%20cate%20no=141&display%20group=1<br />

<br />

Can't tell which card has better build quality though.<br />

<br />

Jesus, wow, any idea when their PCIe version will be out? That'd be much better of course.<br />

<br />

Also, thanks for the thought on your 'R&D leftovers'. Always open to experiment.

[Quest]

The mac mini is compact and a decent performer but it is not fanless and thus has moving parts, not silent (though relatively quiet). As you rightly pointed out as well, there is difference in usb card and power supply.<br />

<br />

I would think mach2music mac mini is more similar to CAPS v2 though it also suffers some limitations.

[89reksal]

Quest, thanks for the reply to my earlier question. I'm pretty confused at this point, mainly because while waiting for CAPS 2 to be announced, I had never even considered using USB out for sound. All my research had been based on S/PDIF coax digital out from a soundcard. <br />

I would like to hear a little more input on sonic differences between USB or soundcard based output. I'm assuming Chris went this way for a reason after CAPS 1 used soundcard. So that leads me to believe USB as implemented here must be an improvement. Would appreciate any or all comments.<br />

Thanks,<br />

Bill

[nhb007]

Hello all,<br />

I couldn't wait for CAPS v2 and went ahead and built version 1.x about 8 months ago, using an Asus 510NTI Atom 525 motherboard (with a 12v DC power supply) into the USB input of an Arcam rDAC and I'm quite happy with it. <br />

However, I'd like to convert my vinyl collection to digital files and I'm thinking of using the ADI converter of the highly regarded ESI Juli@ card which also unfortunately comes only in a PCI version, as well as experimenting with its D/A capabilities. <br />

As a result, I've been looking at PCIe to PCI adapters, but I don't know what the sound quality hit might be like. Beware that YMMV as far as fitting the card into your case is concerned.<br />

<br />

To Jesus and ValveFan:<br />

I have come up with the Startech PCIe to PCI adapter, available from: <br />

<br />

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=6047300&CatId=5507<br />

<br />

as well as Newegg.<br />

<br />

Also to Bob D:<br />

The Asus board is a great one, but has only one PCIe expansion slot, so it depends on what you want to do with it afterwards.<br />

<br />

Regards,<br />

Noel

[Hellen]

Freddie, actually I looked at Mac Mini to replace my HTPC. I wanted one computer to serve as both music and movie servers. <br />

<br />

Because CAPS 2.0 is a purist audio server and doesn't have a video capability to accommodate all the high resolution videos these days, I looked at the Mac.<br />

<br />

But I read that is not that easy to replace their HDD with SSD in this forum, specially the latest version of Mac Mini.<br />

<br />

If just a quiet (as much as Mac Mini) computer is good enough as a music server, isn't a quiet PC based on mini-itx or something similar easier to buy and even cheaper than Mac Mini? One can order such a pc with SSD and a DVD player without trying to replace the stock HDD with a SSD in Mac Mini.

[freddie40]

The new Mac Minis (should be available by Aug) are rumored to have SSDs. If so they will be hard to beat.<br />

<br />

Dave

[audiozorro]

All computers have USB interfaces. As to what interface is best you would do well to reread the USB Audio Primer:<br />

<br />

http://www.computeraudiophile.com/content/Asynchronicity-USB-Audio-Primer<br />

<br />

I would think that for computer audio more typical path is to choose a computer platform or DAC and then select the best interface that maximizes the pair. The 24-bit/192kHz reference interfaces for audio excellence include the Lynx AES16 PCI interface for AES/EBU digital I/O, the ESI Juli@ PCI interface for coaxial S/PDIF, and the Wavelength Audio WaveLink for USB to BNC S/PDIF. If you have an excellent firewire DAC like the Metro Halo ULN/LIO-8 or an excellent USB DAC like the Ayre Acoustics QB-9, you do not need any of these interfaces.<br />

<br />

If you have a laptop computer or Mac Mini then you probably are best served with a firewire or USB DAC. If you have a desktop computer or tower then all options are well served by any of the above reference interfaces or this new SOtM tX-USB PCI interface for USB output, though Gordon or Charlie would best answer whether this USB card makes any noticeable sonic improvement with their DACs. <br />

[beetlemania]

". . . though Gordon or Charlie would best answer whether this USB card makes any noticeable sonic improvement with their DACs".<br />

<br />

to know if the USB card sonically improves the performance of asynchronous USB DACs. Other than the USB card and more memory, I don't see how the CAPS 2.0 is much of a step above CAPS 1.0.

[ecwl]

I was hoping Chris would respond to some of the comments so far.<br />

<br />

I almost got a feeling that Chris is implicitly saying that in the CAPS v2 server, on his system, the SOtM tX-USB + Wavelink sound better than Lynx AES16.<br />

<br />

Obviously, there are so many different combinations one can try and so many async USB-S/PDIF convertor and USB DACs that it will probably somewhat system dependent and there is no way how Chris can review all different combinations & permutations.<br />

<br />

I guess as usual, it depends on my personal budget, personal preferences and experiences what's best for my system.<br />

<br />

[BobH]

I'd be utterly astonished if a USB add-in card made a difference to the quality of sound coming out of any sort of USB dac. If it does, then the likely answer is that the dac manufacturer needs to go back to the drawing board!<br />

<br />

The USB specification is very, very, clear. A manufacturer should be well aware of what they are going to get, in terms of signal specification, and design their product accordingly.<br />

<br />

Specifying an "audiophile" grade USB card is evidently a good idea, in terms of giving people something to talk about and keeping the site traffic up, but that's all it's good for. IMHO, of course!<br />

<br />

If I am just being overly bad-tempered and USB add-in cards are the next essential accessory, then wondering about the next Mac mini will be a waste of time. As, presumably, will be thinking of using a laptop, netbook or any other such device!<br />

<br />

If there is a technical justification for such a card, then every existing USB equipped audio device has just been rendered inadequate. That seems unlikely.