Yes, Virginia, jitter reduction devices are still alive and kicking ass! I currently use both the classic but alas no longer available Genesis Digital Lens (from PS Audio) and the Audio Alchemy DTi-Pro 32 jitter reduction devices with great effect, using them not with CDs but with high inherent jitter digital sources such as XM/Sirius satellite radio. Both work very well, but the Digital Lens has a narrow edge in sound quality and more inputs (5 vs 3). These devices went out of favor starting about ten years ago when stand alone DACs and CD players began to have more effective jitter reduction circuitry built into them. However, even most current DACs that have jitter reduction circuitry are designed only to handle the levels found in CD drives which are much lower that those found in satellite radio or many computer interface devices. Therefore, I (and others I know) have resurrected my Digital Lens and AA DTi-Pro and send the digital signal from my Polk XM tuner to them (in two different systems) , via its digital outputs (either optical or coaxial--coaxial, Wireworld, is better, but the Wireworld glass optical Toslink cable is amazingly a close second!) and thence to my DACs (one system has an AA DAC and the other a Theta DAC). The reduction in jitter and hence improvement in sound quality on the best of the XM stations is nothing short of astonishing. I have gone from barely being able to tolerate more than half an hour listening to XMs jazz and classical music stations, to listening to them for hours on end. Except for the still somewhat reduced or narrow stereo channel separation (similar in effect to the "blend" setting on FM tuners--somewhere between mono and stereo), the sound is VERY close to the best CDs in almost all respects. Jitter, apparently, more than just signal compression protocols, is the far bigger culprit to poor sound quality from satellite radio. Because satellite radio uses 3 different compression schemes, depending on the station (talk and news/weather being the worst, with jazz, classical and "classic"standards stations being the least compressed) reducing jitter alone will not improve substantially most of the stations. However, on the best or least compressed stations, whole new worlds of sound open up.
Interestingly, PS Audio is about to reintroduce a stand alone Digital Lens jitter reduction device because of the many new digital audio sources that are being used, especially in regard to computers, but which have higher jitter rates than most stand alone DACs can substantially reduce or eliminate. I have read several blogs on the advantages of using jitter reduction devices along with the Wadia iTransport/iPod and various music server devices, but I have not seen anything elsewhere regarding the benefits to sound quality from satellite radio or satellite/cable set top boxes (STBs), many of which have digital outputs. I have heard considerable improvement in sound quality from a Comcast STB when used with an AA Dti-Pro, but Verizon's Fios optical cable STB will NOT output LPCM thru its digital outputs--only DDS which neither the AA Dti-pro nor Digital Lens can handle (nor can most stand alone stereo DACs).
Unfortunately in regard to satellite radio, Polk has stopped manufacturing its XM tuner and it is only available now through the used market. I do not know of any other satellite radio tuners that have digital outputs, except for the mega buck Magnum-Dynalab units. The Polk tuner used by itself improved the sound of XM radio somewhat, but not anything like the improvement using its digital outputs and a jitter reduction device. I obtained some improvement in sound quality by going directly to the DACs from the Polk, but not nearly as much as using the jitter reductions devices in the path.
