Quote:
Originally Posted by slim.a /img/forum/go_quote.gif
I inquired about a separate usb to spdif converters because there might people (like me) who love the sonic signature of their DACs (even if it is not the most transparent) but are looking for a better transport using their computer, and I tought that a company like yours would make competitive products in that segment.
While I understand that integrating everything in one box would be optimal, there are separate usb to spdif converters popping out every day (bel canto, musiland, Stello, wavelengthaudio ...) and I believe that a "pro" company could make a cost effective no-nonsense product in that segment of audio gear that many people would be intersted in. This is just my point of view on the subject
OK, I understand what you want. I will reply to that, and not leave it hanging.
I like to do what I do best.
I have been making analog to digital and digital to analog converters for many years. My first one was around 35 years ago (the first 8 bit at 100MHz). I made converters for instrumentation, medical, telecom, industrial and so on. Of course I have been specializing in audio converter for the last 24 years. I chose audio because I am both a musician and an EE (electronic engineer). To do a good job of it, one has to know both analog and digital, and being a musician certainly helps. So I put it all together into making audio converters and some audio analog gear (mic preamps).
USB is a needed function, and so is SPDIF, AES and more. But for me, those are, for the most parts, long protocols, hundreds of pages of what bit to stuff in what register in which memory. It needs to be done, but it is not what I find exciting. So much of those protocols have to do with conforming to standards... The first bit of the first byte tells you if the stereo standard is PRO (AES) or Consumer (SPDIF). There is a bit for copy protection, some bits indicating sample rates, bits for word length... even bits to mark the time of day!
It all needs to be done, and I respect folks that do a good job of it, and when needed I too do it. But it is just not my cup of tea. I like music. I play music. I like electronics hardware design. So I do what I like, and I am my most critical customer.
Other then that, as I already mentioned, integration is a good thing. and putting circuits near each other often yields better results. Using one chassis, one supply (and so on) is more cost effective then using multiple chassis, and supplies... Avoiding cables and connectors and using a 1 inch solid soldered trace often has much to offer...
I am not at all sure that my stand alone USB box would be better then another such box. If both units conform to the protocol correctly, the main difference will be about timing: synchronous or asynchronous operation for the USB (my DA11 asynchronous) and jitter.
When it comes to jitter, most of it is about how well the jitter is being "cleaned out" INSIDE the DA converter, AFTER the USB to spdif conversion.
A USB to SPDIF offering low jitter but driving a poor DA will yield poor results.
A USB to SPDIF with much more jitter, driving a DA with good jitter rejection will yield much better timing, and if the rest of the DA is good, the results will be good (jitter is only one factor in making of converters).
Keep in mind that with a separate USB to SPDIF, there is still a cable issue, leading to the DA. With the cable, one gets more jitter introduced by electromagnetic interference, termination tolerance, separate grounds for the chassis (thus ground currents) and much more (there are at least 5 more factors that come to my mind). Putting the circuits INSIDE the DA, with a proper layout, yields much better jitter outcome.
Regards
Dan Lavry
