Thanks a lot for your clear explanation Dafo!
I see that the Wolfson WM8741 tends to be in the long run the preferred chip for this compass2. Probably the best compromise between detail, softness and overall musicality. As indicated earlier, I am absolutely delighted with the Jds Lab Odac for its transparency and clear presentation. I believe the Compass2 with WM8741 will be an interesting alternative to the Odac.
having said this, are there somewhere clear instructions on how to modify the jumpers configuration and what effect are to be expected on the resutling sound? I mean where are they physically located on the mother board, how to proceed to change them and what results can we expect if it is in position a or b. Basically a tutorial.
Best regards
There are some basic differences between the filters.
First two major groups are the minimum phase- and the linear phase filters.
The advantage of the minimum phase is no pre-ringing and more post-ringing(more post-ringing could be listed as a disadvantage though). This sounds more natural to the human ear. Pre-ringing is sound building up before the actual sound impulse.
The disadvantage is a bit of roll-off in the top frequency.
The advantage of the linear phase filter is… well a linear frequency response.
The disadvantage is pre-ringing.
You can add either "soft knee" or "brick wall" to the above. Soft knee is a slow roll-off in the treble, brick wall is as little roll-off as possible.
You process the signal more times over with your filter effects with the higher oversampling rate. So a high sampling rate will give you a very exact result given the properties of the filter you've chosen.
The "apodising" is a newer kind of filter where the pre-ringing and post-ringing is dealt with. This is a clear advantage.
The disadvantage is small issues with the fase in most of the frequency spectrum. But the audible consequences are inaudible, so it can be argued as irrelevant given the advantages which are indeed audible.
There are pro's and con's to each filter, so it is not a matter of better or worse or right or wrong.
The question is: Which filter do you think sounds the best. It is all up to you, there's is no reference to hold on to, only your own subjective taste in how you like your digital sound.
Some might say: just go with nos-dac's then, which do not use these digital filters at all. True, but the disadvantage is distortion, noise, bad measurings(not that I personally care about this) and in many cases frequency roll-off in both the treble and bass. I am sure good nos-dacs have been made, even audio-gd has a few on their program, but they're expensive and soon to be rare as the pcm1704 dac is taken out of production.
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