Hello, looks like it's been a while since this thread was active, but I was researching the BLA microclock recently and the discussion in this forum was helpful. It seems that the conclusion people finally agreed (or disagreed) on was that the microclock made things sound "different," and subjectively better to some. What's odd though is that I haven't seen any A/B type audio samples posted here or elsewhere to support this one way or the other. So I decided to post some (at archive.org on account of their free disk and bandwidth):
Internet Archive: Details: bastards-clock-test-A Internet Archive: Details: bastards-clock-test-B
Here's the setup. I have an unmodded MOTU 828mkII, and Cakewalk Sonar 4.0.4. I recorded this song 24bit 96K, with the internal clock. I'm using the MOTU's 8 analog outs to feed an old Tascam M-320B console for summing/external effects.. note that there are 15 tracks to this song so I had to choose some tracks for internal summing (like the drums) but some other tracks (vocals, bass) have their own channel on the console. I routed the stereo mains of the console back into the motu/sonar and hit record. I did this once with the motu set to internal clock, and then I did it again set to the microclock. These files are the downconverted result, 16bit 44.1KHz at 192Kbps mp3. Can you tell which is the internal clock and which is the microclock?
Some things to note: firstly, since I didn't record originally with the microclock, some might say this is not a valid test. However, by using an external analog console for summing I'm relying on the motu for one additional D/A conversion and another A/D, as opposed to internal summing. If the clock is going to affect the performance of A/D/A conversion as advertised, we should notice it here.
Secondly, I mixed the song using the internal clock, and changed nothing for the external clock mixdown. If the sound quality is radically affected by the clock source then that could affect my mixing decisions. If this is the case one might notice that one file has a better mix but worse sound and vice versa for the other file.. Personally, I don't notice this. In fact, I'm not sure I notice any difference between these two at all.
Thirdly, I'd like to do this again with a different song (one with kick drum this time) but with three files, one summed "in the box," and the other two with external summing but the different clock sources. Mixing/summing via the console is useful to me when using outboard effects but I'm not at all convinced it results in improved sound quality.
And finally, experiments don't mean anything until they're reproduced. If you have an external clock for DA/mixing purposes, as opposed to syncing a bunch of digital gear, then this is an easy thing to test. Let's hear some internal/external clock A/Bs already.
Louis