In the first place, he sums the sitch in useful language. One example:
Vinnie's very straightforward proposition is that the Ipod's built-in DAC actually is excellent, it is all the follow-on circuitry designed to power headsets, control volume and offer a wide variety of equalization settings that is of poor quality. . . . Vinnie basically connects the ouput of the DAC directly to the headphone jack, putting a high-end capacitor in the path and nothing else.
Another of skilover's virtues: Though he's praising a familiar modification to an ubiquitous device, he manages to notice issues that everyone else tends to miss. Here's an illustrative morsel:
Vinnie's straightforward thesis is this: While the iPod 4G's (Wolfson Microelectronics WM8975) DAC is excellent, its post-DAC circuitry is mediocre at best. The quality of the headphone amp and volume control might even be characterized as poor. His solution to the problem: To connect the output of the DAC to the headphone jack directly, with only a high-quality Black Gate capacitor between the two.
Vinnie describes the IMOD sound as "analog" in nature. . . . It has soul, a certain rightness that, for example, a mid-range CD player lacks. Due to its limited power supply, the Ipod will not have the forceful bass and slam that a very well designed CD player might, but it has a sweetness, a naturalness, a warmth and a certain "rightness" of sound that are just stunning.
99% of Head-fi discussions of the iPod's sound are reducible to this: It is (i) excellent, (ii) awful, (iii) worse than that of my other DAP(s) or (iv) better than that of my other DAP(s). None of that is ever useful to novices or anyone else; it is mere barking and cooing. However, it is extremely useful of skilover to observe that (i) because the iPod's power supply (like that of most other battery-powered portables) is weak, its bass sound lacks the impact of a good home system, but, (ii) subjectively, the iPod's DAC has a certain detail and warmth that old-school audiophile reviewers of mid-level systems tend to praise.
Comparisons between the iPod and other DAPs might be more useful if the DACs used by each were listed by the reviewer, and if reviews included comparisons with a minimum of amp/DSP interference in an attempt to discern the DACs' sound characteristics. Skilover's post suggested that idea to me. No one else's had.
Also: Skilover's mention of the bass-timid power supply suggests the possibility of another sort of mod (or, possibly, third-party solution) that might improve the sound of the iPod, one which no one seems to have attempted. No doubt there are reasons for Vinnie not to have pursued this (perhaps the mod would be impossible due to the case's dinkitude and other considerations), but the idea is worthy of discussion at the very least.
Far from being a mere commercial, skilover's post reads as if he's thought about the problems inherent in the iPod's presentation and asked Vinnie specific questions about the Red Wine Audio recipe for improved results. As a person who has written technical manuals in the past, I can appreciate skilover's efforts.
Welcome to Head-fi, Large S. Please continue to post your lucid and thoughtful observations.