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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ccd - Thursday, December 4, 2008 - link
If you want to be scientific, there is no substitute for double blind testing. It's as simple as that. The human psyche is just too susceptible to suggestion.
I have been in stores and compared components. But as you should know, all sorts of games can be played with equipment. A common trick is connecting a speaker to a monster amp which makes it sound better. The other key to speakers placement. You can take a speaker that sounds great in the store and sounds crappy when you get home because the listening conditions are so different.
The most eye opening experience I ever had was taking a home made speaker into a very high end store at the end of the day because on of the salesmen wanted to listen to the transducer I was using. The speaker which also used one made speaker wires out-performed speakers costing over $20,000! The Orions that I have mentioned in previous posts are better than this speaker and the Orion uses electronics which are hardly out of the ordinary. I would put that speaker up against anything, regardless of price. Listen to a speaker like the Orion and you will realize that "high end" audio is mostly snake oil.
goshwan - Thursday, December 4, 2008 - link
Why should we take your 'subjective' (because that is what it is) opinion that the Orion's are that good? How is your opinion any different from when the author says his speakers or DAC's are great?Have you heard these components yourself? Have you heard any of the components used in the review?
Humans are subjective animals and purchaing decisions usually involve sprinklings of logic and subjective preferences. Audio is one of the best examples of this. Even solid state amps sound different depending on topology and operating class. Your statment about monster amps reflects this. They indeed sound different.
I have heard the TDA1543 on occasion, but I would not be foolish enough to think that every other DAC sounds the same.
Granted, the Orion's are a indeed a fine speaker based on reports, but it's also possible the ones we see used in the article are too.
To mee it seems as if everyone is forcing their own subjective opinion in reply. Some are objective, but theirs plenty of subjective, which is funny really.
I think the article could have offered some more objective stuff. but at the same time, the listening conclusions of both DAC's were pretty much spot on. The TDA1543 is known to sound soft at hf sounds, especially in nonos. The room correction stuff really was great. In fact, I wonder how many readers got that far before exploding their thoughts via the keyboard.
You have some interesting points on blind tests, arguments for and against seem to rage the web over. I wonder what people would accept though, how much evidence would be needed if something turned out to be spot on?
I'm interested to see where AT go with the audio stuff.
ccd - Saturday, December 6, 2008 - link
I guess we will have to agree to disagree. Moving right along, I do not have any issues with open baffle speakers. I'm not a techie, but there are theoretical advantages to open baffle speakers. The trick is getting the baffle wide enough so that the baffle simulates the driver being in a wall. The problem with open baffle speakers has been aesthetics, as an open baffle speaker usually have to be very wide. I've seen open baffle speakers with hinged sides to the speaker need not be really wide except in use. The test speaker uses clear sides which would limit the impression of width.
Actually, my issue with the speaker is that it is full range. I have not heard this speaker, but full range speakers generally have really nice mid ranges and suffer in both the upper range and lower range. I do like that he paired his speaker with a sub. However, full range speakers usually need a crossover at a high frequency than I would like and the higher the crossover, the trickier the integration. In case you haven't guessed, I've hung around DIY circles for a number of years, though not recently.
goshwan - Saturday, December 6, 2008 - link
Well seeing as neither of us have heard the speaker in question it's a subjective assessment. Of course, individual drivers tailor made for the frequency range in question should be more proficient. Given that we hear little over 15Khz though, I bet they sound pretty cohesive. Yes higher range crossover integration does become an issue, but if one is not needed 'subjectively' then why bother?ccd - Saturday, December 6, 2008 - link
The speaker used in the article could be good, very good for all I know. Since I have not heard it, I can only talk in generalities. The tradeoff is between a full range transducer with no crossovers and a frequency response that is not nearly as flat as a multi-driver speaker with crossover points. Neither speaker is perfect.
Full range drivers, at their best, have gorgeous mid-range performance which is highly valued by those who favor them. The tradeoff is a fall off in the upper and lower ranges. The limits of human hearing help cover the failings in the upper ranges and there are tricks like the use of transmission lines to extend the lower range, but there are limits.
The multi-driver speaker has a different set of issues. One is finding drivers that complement each other. Merely matching frequency response is not enough. The other is determining the right crossover points and slopes. Not a problem for an expert, a great challenge for the amateur. From what I have personally heard and from what I know about speaker design, a well designed multi-way speaker, particularly hybrid active (passive crossover between the tweeter and mid-range and active between mid-range and woofer is just a better solution than a single full range driver. Right now, I'm sitting in front of a speaker with one of the widest frequency ranges of any driver and it is still a 3-way design.
Again, I have not heard the speaker in question. But I also know it is VERY hard to overcome the limitations that come with certain design choices.
goshwan - Saturday, December 6, 2008 - link
That's the beauty of audio, final choices are often based upon what you favor. There is no one speaker that will appeal to all tastes. Which is why I don't diss on people going one way or the other. The calculated final response with sub and DRC was pretty flat. Impressive.ccd - Thursday, December 4, 2008 - link
This gets back to my original post on this article. A lot of this is very subjective and there will never be any agreement on it. IMHO, things like DAC reviews should not be a part of this site, it would not matter whether I had heard the components or not. However, the DRC part should definitely be featured on this site and was great.BTW, I used the Orion as an example of a kit speaker which is both generally regarded as one of the best kit speakers available and one whose design runs counter to many of the assumptions made by this author. I encourage you to listen to the speaker and come to your own conclusions.
Double blind testing is the only way I know of to accurately determine whether equipment changes actually make a difference. It is opposed by many in the high end because they don't like what double blind testing tells us: much of what they tout just doesn't make an audible difference.
goshwan - Thursday, December 4, 2008 - link
I 'subjectively' disagree, the DAC kits are designed to run off the USB bus. Tha means a computer is involved.I don't follow your 'assumption' accusations either, like yours the opinions stated are subjective. Linkwitz backs his up on his site true, but the adoption still involves approval by human ear - not just visionary acceptance of theory. That means verbal expression in the form of words which you too have used to encourage people to listen to the Orions. I have no doubts those speakers sound great. But I have heard great things about open baffle speakers too.
I agree with you on this, in that guess we can agree to disagree.
Flyboy27 - Wednesday, December 3, 2008 - link
How much energy do you have to put into a system before you can actually start enjoying your music. I realized many years ago that I just needed to listen to my music instead of worrying so much about sound fidelity. Since then my enjoyment of music has increased so much. I am a musician, have been trained as a recording engineer, and work in the music industry. There comes a point when you have to stop worrying about your gear and just enjoy your music.Having said that it is a shame that so many people listen to 128kbps mp3s. I'm planning on re-ripping my entire CD library in a lossless format. This is part of the reason for me why it is so important to have a physical copy of my music. I'm not "stuck" with a low bitrate crapy itunes copy.
kompulsive - Wednesday, December 3, 2008 - link
You guys should definitely check out the M-Audio Audiophile 192 or Audiophile 2496 depending on your needs. I've been using these and similar products for years in my small studio at home and the price, quality, and value are superb. I think Creative products are grossly overrated and overpriced.