OOps I almost forgot. The data format on CDs is not the same as computer ROM disks, and the data retrieval is much less reliable. |
There seems to be a LOT of misinformation going around about digital. There are different "types" of DACs. When I say DAC, I'm referring simply to the converter which is a chip that converts digital input to an analog output. In addition to DACs for CD playback, there are different DACs and DAC Arrays for commercial use. Many of the so called improvements in DACs are really just ways of producing cheaper DACs. The DACs used on most mass-produced CD players and portables costs about 20 - 25 cents each. So called jitter reducers may not reduce jitter at all. It depends on the sysytem. Most well mated Transport-Processor systems will have a small enough quantity of jitter so that jitter reducers will have no effect or make it worse. I've measured Theta, Spectral, Levinson and a few others and they all had better jitter numbers without any intervening devices. Any claim to produce zero jitter is not to be believed. The device measuring jitter has jitter itself. It's an anomaly of the digital domain. I remember Robert Harley reviewing the Genesis lens in StereoShill and being shocked that different transports still sounded different with this product. This showed me how little these guys really know about audio. |
Now that the DAC's have gotten so much better in the last few years it is much easier to hear the differences in the overall quality of trhe digital signal coming from various transports. Jitter is not the only thing that can cause poor sound from a transport. In my experience most older transports have poorly designed, poorly regulated and poorly filtered power supplies. These power supplies and their associated digital circuits put a far amount of eleictrical junk onto the digital output. However, and usually more importantly, many digital units put a tremendous amount of noise back on the AC lines where it can pollute other pieces of equipment. This is easily demonstrated with a noise sniffer or Oscilloscope. Your Studer, being a pro audio unit from a company known for its fanatical attention to engineering detail probably has a well designed power supply. That said, a jitter reducer like the Theta TLC which I use to isolate my digital satillite using the ATT glass output might make it sound even better. Carefully isolating the AC power supplies from one another also probably will improve your overall sound. |
Thanks for the info. I was just curious, because I recently hooked up my old Studer A727 CDP (their pro model from the 80s...it's very similar to the Revox B226, but beefier everything) and began using it as a transport for my EVS Millenium 2 DAC (with Cardas Lightning 15 RCA coax cable). It sounds amazing to me. It's the most balanced, realsitic sound I've had yet. There is a huge amount of low level info. I thought my old Denon DCD-2650 sounded much better than my Pioneer DV-05, and this sounds much better than the Denon (and the Denon is also built like a tank).
I was wondering about the jitter, because I've always heard that the older players have plenty. If that's true, I don't see how this player could sound so much better than my newer players. Is the Millenium DAC 2 capable of dealing with the jitter on it's own? Is that possible? I've heard that the Crystal chip lowers jitter a huge amount, and the Millenium DAC does use that chip. I thought about trying a DIP jitter reducer, but I don't see how jitter could be an issue when it sounds so much better than my other players. If there was a high amount of jitter, I would think it would sound much worse. |
Marakentz, interesting point. But last time I remember, Rega was not a player in the digital wars. I've compared Wadia, Levinson, and Resolution Audio, here all at once. My favorite was the R.A. I have to disagree about the upsampling. It is the smoothest, most analog I've heard, atleast in my system. I heard it against the Rega, nolo contrendre. |
marakanetz: you say "The ideal DAC does not have any oversamplings" really? from where does your information or opinion derive? -kelly |
On my EAD DSP-7000 MKII there is an error indicator that shows a "jitter" or error reading a digital data. You can hear the jitter from the good quality DAC coupled with bad quality CD-player or Transport. Usually when it there is an error occured from the digital output very often DAC's possibility to correct a huge amount of "trash" is limited and it goes on and on and on up to the end of CD. Even if there is a jitter reducer is present, it may not be enogh to eliminate it.
It sounds like a part of the sound bandwidth dissapears or becomes shallow and unrecognizable. It may be bass, midup or midlow -- any part that you actually cannot predict. At the same time, if I use an analogue output of CD-player without my DAC, everything goes more or less stable certainly with large overall audiable performance sacrifice.
You WILL NOT hear it if there is a good quality dedicated transport coupled with decent DAC, also if there is a bad quality player coupled with the bad quality DAC(with huge amount of oversampling) since the bad quality DACs aren't that sensitive to errors and designed to enhance the signal rather than linearly reproduce it.
The ideal DAC does not have any oversamplings.
These tests were made with Rega Planet CD-player in comparison with my dedicated Monarchy Audio DT40b transport. |
Jitter is easier to hear when it is removed. I use several systems with separate DACs. Each system was vastly improved by using true 75 ohm cables and connectors. IMHO jitter boxes are a must for digital separates. In one of my systems I have two Theta Digital TLCs fiollowed by a Monarchy DIP MKII and then an Assemblage UJB-1. The sound is fantastic. One time I removed the Theta TLCs and I though that system still sounded good, until I relaized that it was missing ambience, soundstage depth... Removing jitter improves bass (more solid) the highs are better (cymbals and bells more natural). Everything improves when jitter is reduced. The music is so natural and lifelike it is hard to believe the difference a good jitter filter or 75 ohm cable can make! |
Pick up a copy of Stereophile's Test Disk #2. There's a jitter demonstration track on it that will show you what it sounds like. It won't necessarily help you to recognize when you are hearing it on your own player, though. If you have never heard a CD player without it, you may not recognize when it's there.
k |
Hi Phild; It's been my experience that when a jitter reducer is used, it removes some to much of the shrillness, edginess, and a harsh electronic sound of particularly low priced CD players. In my case it particularly improved the upper mid-range and low treble, and made music less fatiguing.
I have used Sonic Frontiers Ultra Jitter Bugs with Sony CD players, ie CA9ES and 701ES with good results. The UJB also converts Toslink to coax. I've also used Theta's TLC successfully. You just have to try it to see if it improves the sound of your system. I haven't heard it, but the Monarchy DIP has gotten good reviews. Cheers. Craig |
