As of yesterday, I've found myself in the position to compare various incarnations of the Audiolineoutdock. Since exposure to a loud sound-system has necessitated a rest for my ears, I haven't gotten involved in rigorous testing. Even so, I can make a few cursory observations:
Listening to Bill Evans's Waltz for Debby, I can hear a distinct difference between the Cotton Dock and a Turbodock III with Turbo-confected cable. Even so, I'm not certain everyone would hear the difference or benefit from it over time. Because the Turbo configuration is brighter, a case could be made that the Cotton Dock is less fatiguing. Then again, some listeners favor a brighter sound. For them, the upgrade might not be necessary.
Auditioning the top-of-the-line Singlepower at the National Meet has changed the way I evaluate reference audio equipment. In the past, I'd have associated a brighter sound with the brutal truth, and demanded that a brittle recording be reproduced in all its excruciating glory. However, hearing the Maestro ZR has afforded deep bass and balanced highs a loftier place in my reference criteria. There seems to be nothing particularly objective about privileging metallic sources and harsher setups. If anything, one dulls the mix slightly to compensate for shrill-sounding kit.
I still intend to check mixes against pedestrian equipment to be certain they translate to ordinary consumers' setups (perhaps my democratic/populist leanings are showing). But from now on, I'll bring whatever is necessary to allow my engineers to tune tracking and mixes to higher end equipment.
Which brings me to this brief observation re the Cotton Dock and Turbo Dock II/Turbo cable:
After a few auriclings, I realized the Cotton Dock's bass response is reliably deeper, its mids, more evenly spread, its highs, more balanced, than those of the Turbo or any other iPod setup I've ever heard. This is not the result of some pleasing form of degradation. No veil or visor has been placed over the iPod's highs; rather, the other frequencies are now more balanced in proportion. (I'd love to know how a mere cable accomplishes this.)
With the Turbodock, Evans's high runs and glissandos have an attractive sparkle that puts one in mind of an 80s Yamaha grand, with its deliberately thin shellacking and shallow-felted hammers. The upright bass sounds articulate and deep; sadly, the cymbals and hi-hat still seem digital casualties.
With the Cotton Dock, however, the piano resonates more deeply and its attack acquires mediating overtones. The upright bass, while retaining articulation in the high attack transients, now plunges deeper. Those glitttering brass plates sound far less grating, though no less accurate.
Greater time with these cables will reveal whether any of my impressions are qualified by the placebo glitz effect (Ken's cables look beautiful and are expensive, therefore, one wants them to sound the best). However, my initial experience suggests the Cotton Dock's superiority is not some case of audiophile voodoo. I'm not even going to address the difference between the Zu Mobius Pivot and Ken's Cotton dock-to-RCA LOD yet. The LOD sounded leagues better than the Pivot through my XP-7, but I need more time with that setup to pinpoint the reasons for the difference.
These observations are perfunctory and might change over time. I haven't even contacted the manufacturer about any of this yet: I wanted to post here first, since I imagine he'd prefer it that way.