dap.10
So…. firstly, we need to realise that whatever the red book says about what happens above 20Khz in CD playback or any digital playback come to think of it DOES NOT apply to the output stage electronics and also assumes ideal conditions. In addition, signals above 20Khz are as important as the audible range when it comes to playback as it is a KNOWN fact that many musical instruments have their ‘signature’ above 20Khz and we are now finding out by the use of wider bandwidth electronics and super-tweeters that content above 20Khz is important for accurate low frequency playback.
The red book says all sorts of things… so why do all CD players sound different!
Why discrete?
As a designer, I do not use integrated chips or operational amps unless I really have to, and usually that is because of cost. It is pretty well known that although ICs can give great distortion, linearity and bandwidth figures, the sound quality/resolution issue is enough to say ‘stay away’. I therefore prefer to design using fully discrete technology. The PS.20 phonostage is a great example of the above.
Back to the DAP.10.
Having worked in the ‘pro’ field for a number of years, both in recording live and in various studios, I am fortunate to have been exposed to the processes that occur before the CD is pressed.
Anyone who has been in a recording studio control room (not a friend’s converted bedroom or barn!) whilst a session is being recorded would have hopefully noticed a few major differences between what they were listening to and what a high quality domestic audio system sounds like.
One major difference is image stability, focus and weight. Some audiophiles may think these factors are irrelevant and not part of the music BUT they are every part of what is on the CD and a system that is lacking in these three elements may has a phase/frequency related problem.
The other is resolution and soundstaging. Again very much part of the recorded material and exists on the playback format and is as important as the music itself for high quality playback.
The majority of domestic high quality CD playback systems DO suffer from a lack of all of the above.
What we at Whest Audio realised about 4 or so years ago was that the CD players we tested all suffered from the same inherent problems: Poor image stability, focus, weight, resolution and soundstaging when compared to proaudio analog magnetic tape playback. We looked at what the CD playback output looked like using ‘single tone bursts’ as well as ‘multiple frequency’ and lastly plain old music.
What we found after much analysis using bespoke software and measuring techniques was that all the players tested (ranging from US$1,000 to US$6,000) exhibited a series of small peaks across a 110Khz bandwidth above 30Khz. These peaks also produced a set of ‘time-shifted’ peaks. These peaks are not music related but seem to be ‘triggered’ with by a full bandwidth signal.
The small time-shift causes minute ripples in the domain above 30Khz, possibly by ‘beat interaction’ which later finds their way down to the ‘audible’ domain. These ‘ripples’ we believe have a profoundly negative effect on CD reproduction. What the DAP.10 does is effectively stop the ripples from occurring, thus cleaning up the audible domain. We selected a few of the peaks and by applying a very small correction we can re-align the time-shifted information . It took quite a few months before we arrived at a selection of peaks that once corrected made a substantial improvement to the audible domain. The reduction in ripple artefact post DAP.10 is quite staggering and can be heard in an overall improvement of CD playback resolution, soundstaging, apparent bandwidth, focus and stability. All DAP.10 owners have commented on the extra low frequency extension and far better separation of instruments in a bigger soundstage.
What causes the problem that the DAP.10 corrects is an unknown at this stage but we are researching in to it. I suppose the majority of high-end audio reproduction is R&D as most designers will say.
Thus DAP.10 does not interfere with the inherent audio quality of the system it is connect to. The systems audio signature isn’t touch in the slightest but what is does do is allow the system to:
1. resolve much more information
2. increase apparent bandwidth at both ends
3. increase soundstage width and depth
4. increase image stability, focus and weight
The DAP.10 will quite happily sit along side a $1500 CD player and allow it to outperform a CD player costing 3 times the price! or connected to a High-End unit making it ultra-high end!
- Frequency response: 2Hz - 210Khz -0.5dB /- 2dB
- Working band: 33KHz - 195Khz
- Technology: ULN Discrete Quad line-up
- THD+N: 0.01% Gain unity
- Connections: Unbalanced
- Connectors: Gold Audiophile
- Unpacked weight: 3Kgs
- Packed weight: 4.2Kgs
- Dimensions: 2 x 285mm x 107mm x 62mm
- Operating voltage: 230VAC 50Hz or 115VAC 60Hz
