Romy wrote (in blue) :
"... Are you saying that you are able to play from your PC music that you got by ripping CD and you have better sound from PC? ..."
Yes, and because of this it would be accurate to say that my system is music-server-centric.
"... Are you re-clocking and up-sampling the 16bit CDs when you load the files to your PC and then feel that it give a better quality?..."
No. The DAC is a Wavelength, Cosecant Version 2 (so not the latest version). This is a 16/44.1 USB (not S/PDIF) DAC. It is a non-over/upsampling design ; Data in = Data out ; No filtering or other manipulation. The unit incorporates an onboard USB controller (where an S/PDIF DAC would have it's receiver chip). If I understand correctly, in the case of this DAC, the word clock signal is generated within the DAC unit.
Ok, lack of jitter; very good, and no doubt one of the keys to the quality sound this DAC delivers, which I would characterize as possessing the following properties :
Tonal balance top to bottom
Preservation of harmonics (very nice with ML2s)
Beautiful imaging and S P A C E !
Clear rendering of small details
Very good attack and decay (notes play out naturally)
Excellent (not dry) bass
Result : Music that is free of the smell of hifi... This is how I would imagine good analog should sound.
According to the manufacturer "...The output stage of is the key design element which is responsible for the overall sound..."
I have not mentioned this device too often here, because, well because the unit in question uses a tube in the output stage... And we are after all, talking about a source component !
I do wish others here would give this DAC a try.
Regarding theoretical advantage of the USB interface as implemented in this DAC :
I have grabbed information from various sources, and compiled it here (in green); it might help to explain ... This is, for the most part, taken from the marketing pitch of the DAC's creator :
"...The USB interface is bidirectional, and has built-in error correction and buffering at both ends; it is an asynchronous interface. Clocking synch problems associated with SPDIF are not present with USB. The result is that the data on the disk is identical to what is leaving the DAC all the time..."
"...At start-up, the DAC tells the computer it can handle 16 bit audio at 32K, 44.1K and 48K. Since the USB receiver only has to handle these 3 frequencies, the clocking to the DAC has almost no jitter. SPDIF actually has to be synched to the exact frequency of the transport (i.e. if the transport is working at say 44.0896K instead of 44.1K the DAC has to sync to that frequency). Therefore the jitter problems of SPDIF are all but eliminated. The result is a zero error protocol to link between computer and DAC, with ultra low jitter..."
I wrote that there is no filtering : However, this unit uses a tube in it's output stage ("...Once converted, the analog signal is sent directly to a 6GM8/ECC86 dual triode output tube, which in turn drives a pair of output transformers..."); the tube probably has some sort of filter-like effect.
Importing files :
"... What do you use as the wiping software and what wiping transport you use for the initial read of the CDs? Am I missing coming?..."
(I assume "wiping" is a typo, and what you mean to say is "ripping software")
All importing is done with iTunes using AIFF encoding (a sort of lossless zip file), with "Error Correction/Recovery" option selected. I use a PowerBook G4, but the DAC will also work fine with the Windows platform (Romy, there is no reason to fear the Apple... The only real difference lies in the OS... A high-end Mac will come equipped with hardware that is more oriented toward multi-media processing... I will admit that some of the Mac clients are frightening!) The optical drive used to import is external, made by LaCie, with FireWire interface (nice and heavy, it sits on a thick piece of foam).
Here is an explanation of the theoretical advantages in using a computer (and not an audio transport) to read/import CDs :
"...A computer has the ability to read a CD and save it in an error free state. Transports, even the best of the best, cannot go back and re-read a track when they have a read error...."
Computers also have vast amounts of memory and because they are not constrained by time can re-read a track until it writes an error-free version to the hard drive..."
Storage of the files is handled by one of 3 external FireWire 800 hard drives.
I chose FireWire external drives in all cases in order to reserve the USB interface exclusively for communication with the DAC. Also, the drives can be daisy chained together, making it simple to add storage capacity.
Cables are nothing special : Shielded USB and FireWire 800, all kept under 4 ft in length (ferrite collars at both ends of FW800 cables).
The future ?
Wavelength is now offering version 3 of this DAC, which incorporates "Asynchronous Mode USB Audio" (previous versions to this DAC can be updated).
"...Asynchronous Mode USB Audio. This means the computer is controlled by the USB DAC. An ultra-low-jitter audio master clock located in the DAC controls the audio transfer rate from the computer... The DAC module will work at 44.1k, 48k, 88.2k and 96k sampling rates at 24 bits... These DACs use no operational amplifiers (opamps) in their design. The DAC module is the only Solid State portion of the overall DAC..."
How to short-circuit evolution: Enshrine mediocrity.