Hi pedal,
When I finished writing the below, I wanted to scratch it again because it doesn't seem to make a difference to matters. But my curiosity stays on what you actually meant by the 10KHz phrase and all. You could mean that such a high frequency tone is hardly audible anyway, so how to hear a difference between a square and a sine. But since you also emphasized on the capacitor thing *and* your DDDac doesn't have them, all together I wonder what the message is. So I did not scratch it
:
Sorry for been unclear. Writing about technical matters during the night in foreign language, while drinking Cognac, may introduce errors. It’s known as “midnight jitter”.
(If you try to listen and compare square and sinus tones above 10kHz, they are in fact not much different).
I just wanted to confirm your findings that jitter could be more audible at low frequencies than (much) higher up. I have done some listening tests with a software based tone generator. A 100Hz square wave sounds very different from a 100Hz sinus tone. But with frequencies above 10KHz the audible differences between square and sinus waves becomes less. (Of course you hear the difference, but less than compared with lower frequencies). Also, it must be added, that in music the highest levels are found at lower frequencies, among the instruments fundamental tones. In the treble it’s seldom max amplitude.
BTW, “99%” of all DACs have a capacitor on its output, so they don’t pass on any DC components to the amplifiers. So true square waves cannot enter the amplifiers. Again strange, because your DDDac has no caps in the output stage I think. Or ... or maybe you explicitly talk about the TRUE square waves ... they indeed cannot exist in electronics.
-Yes, it was a reminder about the fact that if jitter is causing square waves, it will not pass through the DAC as a TRUE squarewave. (Most DAC’s have a capacitor on it’s output stage, to filter DC from entering the amplifiers. Including my DDDAC from Doede Douma). But there are a few DAC’s who are DC-coupled. (f.ex. AYRE). This can easily be read from its specifications, if the frequency response is stated from 0 Hz and upwards. So I think such DACs could be VERY sensitive to jitter at low frequencies, because they can transmit TRUE squarewave distortion into the amplifiers.
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Something else: I have an analogy about audible jitter at low frequencies. With a jittery signal, the sound is similar to view something through an out-of-focus lens. When something is out of focus it tends to look bigger and bloated (“MORE”). But when you adjust the lens into sharp focus, then the objects you watch becomes slimmer and more precise (“LESS”). So when removing low frequency jitter with XXHighEnd S-1, the improved bass will be perceived as “LESS” (compared with the bloated jittery bass). This can be compensated with adjusting bass level or loudspeaker position. The result being a more correct bass performance, both in terms of accuracy and level.
pedal
