Upsampling DACS: Take the Pepsi Challenge


HAs anyone used 2 of the following 3 relatively inexpensive upsampling DACs: Perpetual technologies, Bel Canto, MSB Link 3 with upsampling upgrade?? I am trying to sort out the details of the new technologies. The Perp Tech can "interpolate", while the others do not. I am under the impression that the "24 bit" part of this new technology has to do with s/n ratios aroung 140 db, which is great, but a little useless considering the other equipment in the system. The sampling freq is the part that has me all aflutter, because it seems to be getting closer to analog quality "infinite sampling" if you will... What do you think? Has anyone compared these dacs?? Thanks, gang.
gthirteen
I'm fully aware of RIAA pre-equalizaation, and the reason for it. And for your information, I already am a recording engineer (I make my own, which is more than you can do), so there goes that little smug blather-theory of yours. YOU STILL DIDN'T ASNWER THE QUESTION, AND CERTAINLY NO CANECHOIC CHAMEBER IS REQUIRED. You can't hear squat, old man, get a hearing aid, already!!!
Please don't tell me that the phono stage doesn't have the equalization that re-boosts the treble response, because that is basic, and everybody should know it. Why don't either of you (Albert or George0? There is no "inherent" roll off. There is only pre_equalized roll off, that is "decoded" by the treble BOOST (like 40 dB) in the phono stage. All of you need to better eduacate yourselves about that. LP's produce harmonics well beyond 25 kHz, didn't you know that? CD's produce nothing at all above 20 kHz, that is fact. I can hear 20 kHz sinewaves on a test CD with Maggies, and the intermodualtion and squared off-ness that goes with them. Can you? You don't need an anechoic chamber, just a damped lisening room (I doubt George even has that, though). And for your info, I've been in a few dorm rooms myself, and saw no decent stereos, just stale pizza (and a few other nice things). Your comments are anectdotal, and prove ABSOLUTELY ZERO POINT. Take a break, and organize your thoughts in your brain first next time, George...
And also, don't tell me about hearing tests with headphones. They're flawed from the get go, no matter how "calibrated" they are. My HD-600's are infinitely better and more extended in the treble than the phones they use in hearing tests, and THESE SENNEHISERS ARE NOT FLAT IN THE TOP OCTAVE. My Maggies are much more flat in the top octave. I think it has to do with the fact that the trasducer is right on your ear, and phase anomalies occur, with sound wavelengths that are, what, half an inch long? Anyway, speakers in a correctly treated room, a good test CD, a mic referencing a 1 kHz sinewave to the mid 80's decibels range, is all you need. My Maggies stay focused DEAD CENTER in every band of uncorrelated third octave pink noise. They make a ball about 2 feet diameter in the upper bass, and a golfball size "ball of noise" in the top ocatves............................DOES ANYONE ELSE'S SPEAKER SETUP/HEARING YIELD THIS? Me want to know........I CHALLENGE YOU TO DO THIS TEST RIGHT NOW (the Sheffield "my Disc" will do the trick. Otherwise, don't go telling me what I can, and can't hear, through my system, old man. Go pipe your pompousity up your own keester for a while, George....
Carl you are a horse's behind, a point that you continue to prove. Oh, and BTW - come back when you get a real system. Maggies compared to Soundlab Ultimate 1's. Hardly. What a joke. You are boring. I'm out of here. Nothing to learn from you, that's for sure. How did those Barney tapes you are so famous for recording work out? Did those on 8 track tape, didn't you?
Carl, a couple of points for your "gray area": 1.) oversampling/upsampling without "interpolation" is meaningless!!! Interpolation is simply selecting the best bit value to assign to an oversampled data point. You could linearly "interpolate" between (real/original) data points or you could fit some base curve between those data points. If you increase the sample rate, you MUST interpolate! 2.) The ONLY difference Kevin Halverson mentioned was semantic (and I'm sure he meant it as such)!! "Upsampling" units started as stand alone oversampling digital filters to improve the performance of lesser processors. There is NO difference!! The term "upsampling" caught on, in part, due to ignorant journalists, and now everybody is using the word to claim some magic improvement. Also, both external oversampling digital filters ("Upsamplers") and internal oversampling digital filters are upstream of the "DAC". A digital processor and the DAC(s) are quite different. A digital processor has 4 main sections: Input receiver (reclocking), oversampling digital filter, DAC (digital-to-analog convertor), and analog output. So, we have once again come full circle: upsampling and oversampling are the SAME THING!! SYNONYMS!! Ask Gmkane for further details. Jordan