Case and Power
My preferred PSU is a high-speed ultra low noise regulator based on a design by Walt Jung. Again, this is a partial DIY kit that is provided by Peranders Sjöström and known as the JSR-03 regulator. The JSR-03 is used as a pre-regulator, outputting around 9V to the I2S and WM8741 modules. Although a 12V relay is present on the Doede PCB to select from PCM2707 or TDA1543 output, I found a 9V input perfectly capable of making the relay switch. The USB to I2S DAC has an onboard 6V regulator circuit that requires around a 2V margin to regulate effectively, so I'm within its bounds.
 A Maplin KR56L Aluminum case provides ample room to house all the PCBs, with enough room left to add modules at a later date if required. |
To provide the raw or pre-regulated DC, I use either a 12V Wal-Wart PSU or an 1800mAh 12V Li-On battery pack. Total current draw of all combined parts is in the region of 500mA, so the battery pack allows for around three hours of listening before needing a recharge. An alternative would be to buy a high capacity sealed lead acid battery, though I decided against that mainly due to the additional shelf room it would require. I only use the battery packs for critical listening and component comparisons. For normal everyday use, the battery pack is simply removed and input switched over to the Wal-Wart PSU. Subjectively, I find the battery input to provide cleaner, tighter bass notes, more perceived air throughout the mid-band and high frequency range, and better stereo imaging. It's not a smack in the face difference compared to the Wal-Wart PSU, as pre-regulation by the JSR-03 offers superlative noise rejection throughout the audible frequency range. Still, the difference is enough for me to accept the hassle of changing out and charging batteries for that last ounce of playback clarity.
If you're not interested in going to the nth degree of audio resolution, the Wal-Wart solution is probably the best way to go. You'll also find some discrete regulator solutions offered in package deals with these DAC kits on the DDDAC and Twisted Pear pages. Either of these options should lead to a very satisfactory performance, although the Jung based regulators have superlative paper specifications.
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Christobevii3 - Monday, December 1, 2008 - link
What about using a dts/ddl sound card to output to a basic receiver?Rajinder Gill - Monday, December 1, 2008 - link
If going to the nth degree for 2 channel it’s hard to look past USB-I2S in async. For multichannel, a DTS/DDL card is perfectly adequate. Although I’d still use an external solution if I could find one.wolrah - Monday, December 1, 2008 - link
How do you figure I2S is any better than S/PDIF? S/PDIF supports up to 20 bit resolution at either 48 or 44.1 KHz, so it can carry a CD audio stream natively. The bits on the disc are the bits flowing out the optical port on the back of your gear of choice.In theory an I2S signal will be able to take more interference, but when we're talking optical signals in a home environment the kind of interference needed to make a difference would be on the scale that you'd never be able to listen to anything.
Goty - Monday, December 1, 2008 - link
Well that's easy to answer:Nope. I'll stick with my Martin Logans, tyvm.
wolrah - Monday, December 1, 2008 - link
In fact it easily can, because plain and simple reading from the disc itself is error prone. A one time rip to WAV or [lossless format of your choice] using cdparanoia on its insane mode output through a high quality sound card will be the same as or better than any silly 4 digit CD player.Even playing straight off the disc, there's no reason to believe any "audiophile" gear will play a CD any better than any other CD player unless there's a design flaw like a crappy power supply.
On the note of power supply, am I the only one who laughed at the bit about the battery vs. the wall wart? Who wants to bet that he's never double-blind tested that one. That's the wonderful thing with A/V gear snake oil, it's very easy to hear what you want to hear.
mindless1 - Monday, December 1, 2008 - link
I've hand-built amps for years and double-blind tested batteries and wall warts. Yes there is a difference. A good (read: overkill for anyone not into building audiophile equipment) localized power filter stage, if not localized regulation, would ideally negate the difference between the two power sources but that can also unnecessarily increase the build complexity, time, and cost.PS the battery is almost always inferior assuming the wart has proper shielding or is inadequate in capacity, and generally I refer to a wart as only a transformer and rectification stage, not trying to build an entire high precision linear regulation stage inside of it due to limited space and EMI.
Rajinder Gill - Monday, December 1, 2008 - link
Martin Logan makes electrostatic loudspeakers if I recall.I'm not sure where that fits into using a PC as a transport and for DRC. Unless you're refering to the approval of open baffle design loudspeakers using te supravox drivers?plonk420 - Monday, December 1, 2008 - link
this is surreal...my $20 Chaintech AV-710 just died in the last 48 hours. i've been trying to resist the Head-Fi audiophile talk and try to find cooler heads to verify whether or not i should go X-Fi or DAC (something silly looking like the HotAudio HotUSB1 or Silverstone), or try to figure out if i'm experiencing the placebo effect "falling back upon" my ALC883, which i can swear "doesn't sound as good" EVEN THOUGH i'm fully aware of the power of placebo.
i'm not sure i liked the mixed bag of positive and negative reports on (cheap) X-Fi vs Xonar vs X-Fi USB vs some DAC vs E-Mu 0404/0202
mindless1 - Monday, December 1, 2008 - link
Choose a Creative card for gaming sound effects. Choose a DIY DAC for highest audio quality at a reasonable price. Buying some cheap commodity grade DAC is a gamble, I'm not familiar with those two products you mentioned but generally in the consumer segment and price range you end up buying an idea, a type of tech but not excellence in that execution.MOtherboard integrated audio usually doesn't sound as good including one using ALC883, though someone with poor hearing or gear may notice the difference less and less depending on where the weakest link in the chain is and how bad it is.
Gannon - Monday, December 1, 2008 - link
I have an X-Fi and it's better then my audigy, mind you I got the more expensive version with front panel and the remote. I use it for everything and have never had a problem, though I don't use vista at all just XP.