Originally Posted by arnyk
This leads to the curious situation where supposedly high end digital players and decoders may be based on the same signal path components as relatively inexpensive AVRs. In some cases the high end products are mid-fi components with tirival cosmetic changes or no meaningful changes at all.
You are both correct and not
. It is true that high-end companies are stuck with some of the same mass-market parts as the high-volume, cost-focused products. With their low volumes for example, they are in no position to to go and build their own HDMI transceiver.
That said, what happens regarding jitter and DAC performance in general, relies a lot on good hygiene. And that hygiene in circuit design is usually outside of these major parts. A superbly clean linear power supply is much more expensive and heavier to produce than a cheap switchmode power supply. But clean power becomes important when even when reproducing 16 bit data, every bit of that sample represents 0.00002 volts (an AA battery is 1.5 volts). And for 24 bits, it is an incredible 0.00000008 volts (hence the reason we cannot achieve it). A lot can get in the way of such small values and good designs can sharply reduce the level of distortion.
So while it would be great if high-end designers could cook up their own optimized HDMI solutions, we have what we have now. My solution to it is go where the designer can optimize things. If I have a music only system, right now my choice of interconnect is USB with the right receiver. Here is one device I use has this great article on their jitter measurement: http://www.audiophilleo.com/definitions.aspx?jitter
. As you see he is achieving 8 picoseconds of jitter (albeit, in his modified test jig). For $500, can get ultra clean interconnect to your DAC. The device is plug-and-play and goes in-line between your PC and any S/PDIF input. I tried it on the $1,200 Nova and even there, the performance improvement was quite nice! It took the device from mid-fi to near high-end. It was quite enjoyable to listen to it then, relative to its own USB input.
Why should it matter? Is our correspondent suggesting that in 2011 the SOTA in mixed signal design is so poor that we can't put a DAC in the same box with a front panel display? What about all those high end DACs with non-switchable front panel displays? All junk?
You are taking my homework exercise for the readers as a PhD thesis
. I always think of cheap and simple exercises people can run at home to learn more about their equipment and the limits of their hearing. That was the purpose of the exercise. That said, both my Mark Levinson and Berkeley DACs let you turn off their front displays. I would be OK if they did not because I know they pay far more attention to front-panel design than mass market designs. To wit, I do not notice a difference in switching their displays on and off but do in mass market sources such as DVD players. Their switch then is to keep their glowing lights from disturbing you.
This hardly looks like a proper listening test to me. If our correspondent is such an advocate of DBTs, why is he advocating such a crude sighted evaluation?
What's crude about it? Go ahead and run it blind as I have done. Close your eye, and push the switch on and off many times until you lose track of whether it is on or off. Then do it slowly and decide which switch setting is producing better quality if at all. Then open your eye. Write down which way you preferred it (assuming you did). Then do the test 2 more times. Do all the results agree? Then you have pretty conclusive data for yourself that there may be some smoke there. Not enough to get published in AES but good enough to base a post on it in a forum.
If you want to be rigorous, then subject friends and family to it. Do this, and you will be years ahead of just about everyone out there. You want to learn, this is how you learn, not reading opinion and generalization of people like me
. Nothing replaces your ear, testing your gear. I could test 10,000 people with 10,000 other pieces of gear and may still not be representative of what you have.
I did a little research. Madrona Digital is a dealer/installer in the Belleville Wa area. I wonder if I could get JJ to drop in and give him a reality check? ;-)
Yes, Madrona Digital is my toy shop
. I get to play with even more gear than I can buy for myself. It is amazing how that accelerates learning.
As for JJ, I should ask him to come over. You probably don't know that I hired him at Microsoft from AT&T Bell Labs to come and revamp the awful audio pipeline in Windows XP. Within the limits of what we could get away with our PC OEMs who never wanted to spend a dime extra, I think he did very well.
Yes, I know JJ thinks all audiophiles are crazy and delusional. But he worked in my group and put up with me there. I am sure he will be tolerant of me in the showroom.
If you know JJ very well, you would also know that he takes certain enjoyment out of beating the crap out of audiophiles for the sake of it. They do make it easy for him if they don't do their homework and learn the science and engineering. While I am not as extreme, I enjoy doing the same at times to the other camp.
Maybe I can get him to see the other side a bit by listening to our superb PC-based music system. OK, maybe not.