It is clear now that the current boundaries the Q1 parameter provide, can exceed peoples' systems. It depends on the DAC and theoretically the CPU plus the combination of both.
As a reference : I use a TwinDAC+ with in between a Fireface800. How the latter exactly is related is hard to tell, and it is even possible that that one is determining for my system; my buffer settings for the Fireface are 128 currently, and it is a leftover of the 0.9h version, where I found this better sounding than the 48 it can be set to ultimately, with further theory that for 44K1 it can technically handle that (another RME user (DSP Hammerfall) pointed out that 24 still will do).
As a further reference my Q1 settings would be able to play without cracks and pops (skips) between a virtual -30 and +45. From this we could learn that for those who find one of the current boundaries (1 resp. 30) the best, let them speak, so I can extend the range.
When going towards the boundaries, both can have impact on the CPU. For me this is
just visible, for others ... it may choke. I use a Core2Duo 2.4Ghz (E6600), and really one core is used by XXHighEnd.
With these more or less CPU constraints, the remainder is related to the DAC.
Because each DAC is subject to jitter already within itself (and the electronics around it), it is hard to predict the influence of the Q1 setting.
Elsewhere I said "the lower the better" but this is not necessarily true and it would depend on the amount of jitter the DAC inheritantly has.
Also, when the DAC and its electronic surroundings contain too much jitter I don't think the Q1 parameter can get it right all the way. It still would influence but I can't tell how and it would be different per DAC.
When you start to hear clicks and pops it means that the data is overridden because of bad timings or it is skipped because of choking. The latter seems clear because of CPU impeeded, but this already is not necessarily true. All is one major interaction of things and in the end it comes down to, say, computer technology. According the first, bad timings, I won't even start explaining. But for you, in order to visualize things a bit, suppose the data is fed too late to the DAC (which would be when it consumed the previous bunch of data) you'd have a skip. A silence.
With the latter in mind XXHighEnd does its thing and it does it under influence of Q1. Although the stepping of the parameter is kind of linear it is (explicitly) not said that in one direction you'd receive skips. It can happen in the other direction just the same.
It would be true though that the slider "adds more" in one direction and "has less" in the other. That's what I meant with "kind of linear".
Functionally you can't do more with it than *knowing* that once you cross a for you technically working boundary, you won't find another working area above that (when going upwards) or down that (whereever it stopped working).
With "technically working" I mean : without clicks and pops.
Within the working range you should be able to influence jitter.
For me the working range seems relatively large, for others it may be very small.
If you can tell the CPU is choking (which I cannot imagine, but anyway) then things obviously can be solved by a better grade CPU.
If it is not the CPU there is no advise; I could tell you to buy a DAC with more headroom on this but it would be a nono advise already because each has different reasons for a DAC. One sounds better than the other to your own judgement, and who says that it's quality can be influenced for the better by Q1 anyway (yeah, actually I say this, but it would be dangerous to take it as a guarantee as of this moment).
Also watch this line : In a few months time we will have different insights again.
Peter
