Twisted Pear Audio Opus
The second of our picks comes from Twisted Pear Audio's Opus DAC. Twisted Pear Audio is the collaborative effort of Russ White and Brian Donegan, who are both capable engineers and audio enthusiasts. The benefit of this teaming is that we find a number of kits ranging from volume control, selection controllers, DACs, voltage regulators, and even amplifier modules based upon some of the latest technology and at prices that blow the world of high-end audio wide open.
The Opus is based on Wolfson's WM8741, a differential voltage output DAC that supports up to 24-bit 192KHz resolution (source permitting). Dedicated output stages and power supply kits are available from Twisted Pear, designed from the ground up to compliment the Opus DAC. For those of you wishing to drive into single ended inputs on your preamps or amplifiers, the Ballsie converter/buffer module is the way to go. Total price including the Ballsie modules will range from $200~$350, on par with the price range of Doede's kits mentioned earlier. The Opus is available in a variety of configurations, from a bare PCB to a fully soldered and ready to go kit. There are no components to solder in any of the full kit format options, apart from the input/output terminal blocks depending upon individual configuration requirements.
USB to I2S input modules are also available, although Twisted Pear's design powers the PCM2707 from the USB bus. An asynchronous clock module is available that allows the I2S stream to be re-clocked, thus lowering jitter to aid high fidelity audio reproduction. Another option, rather than using the USB to I2S converter, is to opt for the MUX receiver module. Up to four S/PDIF inputs can be connected while a control switch allows you to select the preferred input. The MUX module is capable of outputting 24-bit PCM in I2S format for those who wish to playback recordings of this resolution.
I decided to use the Doede USB converter and go with a dual differential Opus DAC configuration requiring two PCBs both switched to mono mode supporting stereo left and right respectively. In my case, audio output feeds into a 3A5 dual triode per channel, followed by a Sowter 8650a balanced to a single ended 9:1 ratio output transformer. This is probably not a setup that will appeal to those immersed in the merits of signal to noise ratios and accurate square waves, but it's a solution that sounds very appealing to my less than golden ears.
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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.