Jitter reduction, best device?

Mapman,

It sounds like you may be hearing beat frequencies. This is a subtle effect that could come from a number of things - including your room setup and/or listening position. It is, as you say, nearly impossible to be conclusive that any specific audible effect is from jitter. Jitter is a detail that does not necessarily stick out like a sore thumb. The industry continues to argue about the thresholds of its audibilty....

Shadorne,

The description of beat frequencies fits what I heard.

It was very consistent though with many CDs I played even listening in different rooms on different speaks to the same source.

I never heard it in several high end reference systems I listened to at the time.

Changing to the Paradisea from the Denon's built in DAC seemed to end it, so I suspect it was some artifact resulting from the Denon's DAC.

Jitter is a mysterious bugger indeed!

so I suspect it was some artifact resulting from the Denon's DAC.

It can often be subtle but everyone agrees that DAC's do sound different. Whether this is the effect of jitter reduction or simply the result of a different output stage (tubed) or both is nearly impossible to say.

Asi_tek - Upscaling, also called asynchronous resampling is not bandaiding. It is instead (and not on the top) of traditional extraction of data.

In typical CD-player, as far as I know, stream of data coming from the laser has jitter and varying frequency. Phase Lock Loop is used to sync DAC converter clock to average frequency of the data stream. I believe that now they use double PLL to improve response and FIFO buffers to provide more stable DAC clock.

Upscaling reclocks data with asynchronous clock of much higher frequency. Benchmark DAC1 does manipulation of data equivalent to 1 million times oversampling making DAC clock accurate to 5ps. DAC1 also has PLL but very crude and fast - just to get input data.

Typical CD player has some analog circuitry that mutes the output in between tracks or during invalid data. This circuitry is audible according to some users who tried to disable it. Benchmark detects valid signal and does muting in digital transmitter chip.

bottom line: the only way to tell if a jitter device will do something in your system is to try it. everybody could guess all day long about things. but in the end, you won't know if it works or not for you until you test it. also, all the room tuning devices, ac filters, 20 or 30 amp dedicated wiring, room lens, different speaker positioning, claws, beaks, better cables, better power cables, etc... i don't think you can say that none of these will not have an impact in your system until you try them.