The DiyMod

The diyMod is a project inspired by the Red Wine Audio iMod. The iPod is modified such that audiophile capacitors replace the stock ones coming from the audio CODEC. This instructable covers the reasoning behind the project as well as how to carry it out for various models of iPods and other portable media players.

Concept

The diyMod replaces a capacitor with that of the user's choice. Audiophiles have preferences for what sounds better to them, so this project gives them the option to swap in the brand that pairs best with their audio system.

A component that lies directly in the signal chain has a sizeable impact on the overall sound quality. From studio recording quality to file size, cables, and output devices, the scrutinizing audiophile painstakingly examines each aspect of the audio delivery system. It is a matter of debate amongst all music lovers as to the size of that impact, whether it be cosmetic, measurable, or even psychological.

The output of the audio CODEC typically carries a DC signal, which could mean damage to audio equipment. Headphone signals are fairly low power, around 10 mW. Even a small DC signal has enough current to melt the very thin wires in the transducer. One way to block the DC signal is to use a high pass filter, which blocks low frequency signals and allows high frequency signals pass through unimpeded. DC can be treated as a 0 Hz. One form of high pass filter places a capacitor in series with the signal, which can have a big impact on the sound depending on the design and quality of the filter components. The diyMod modifies this high pass filter.

Glossary

Capacitors are one of the fundamental electrical components. It features two charged plates with a dielectric in between. Each dielectric can store electrons in varying degrees, which is why audiophiles fuss about them so much.

CODEC is short for Coder-Decoder.

DAC is digital-to-analog converter. Music is stored in digital files, but audio is an analog signal.