IFi Micro IDSD Diablo Portable DAC/Headphone Amplifier

The Burr-Brown True Native® chipset means file formats remain unchanged or ‘bit-perfect’. This means you are listening to music as the artist intended in the format in which it was recorded.

At iFi we use Burr Brown extensively in our products having selected it for its natural-sounding ‘musicality’ and True Native architecture. Our experience with this IC means we know how to make the most of it.

Balanced, differential analogue circuit design has long been championed for its ability to reduce noise and cross-talk within the signal path by fully separating the left and right channels.

PureWave is a new, balanced, symmetrical dual-mono topology with short, direct signal paths. The name refers to the sonic purity it achieves thanks to exceptional linearity and infinitesimally low levels of noise and distortion.

‘Negative feedback’ is used in amplifier circuits to compare the output signal with the input signal and correct errors, in order to control gain and reduce distortion.

For sound quality, this is positive; BUT commonly applied, one-size-fits-all ‘global negative feedback’ can also highlight different problems at the same time as solving others – corruption of the error signal, phase shifts, group delay and so on can all have a negative impact on sound quality.

We recognised that different parts of a circuit benefit from specifically optimised feedback loops and have developed a negative feedback system that is much more accurate than the usual approach. This incorporates multiple feedback paths instead of a global loop, each path optimised for a particular function and working synergistically with the others to deliver optimal overall performance.

Extensive jitter-eradication technologies are applied to the digital stage, including our GMT (Global Master Timing) femto-precision clock and intelligent memory buffer. This represents a total ‘out-of-the-box’ systematic digital solution that solves jitter once and for all.

An important aspect of the circuit design is its direct-coupled nature (no coupling capacitor is present), achieved without a conventionally applied DC servo.

DirectDrive® equals a direct signal path which means less signal degradation. This direct signal path is unequalled in audio and is the reason why the sound is so ‘true’.

As with many other iFi audio products, we’ve incorporated a custom OV Series operational-amplifier. This top-notch component contributes to the extremely low noise, low distortion (0.0001%) and wide bandwidth.

Switching between settings has been engineered to ensure sonic transparency with advanced trench technology MOSFET is used as a muting switch.

This FET-based switching is handled by a micro-controller, which only ‘wakes up’ when the user changes a setting, thus eradicating any sonically deleterious interference.

TDK C0G (Class 1 ceramic) capacitors offer high stability and low losses for resonant circuit applications.

Getting ever closer to the theoretical ideal of pure, frequency-constant capacitance, these capacitors reduce capacitor-induced distortion to vanishingly low levels.

They are pricey but are a perfect addition to our products.

Panasonic OS-CON caps totaling 5,410uF give very-low Equivalent Series Resistance (ESR), excellent noise reduction capability and frequency response characteristics. In addition, OS-CONs have a long-life span and its ESR changes little even at low temperatures since the electrolyte is solid.

They are not often found in products costing <US$1000.

Vishay MELF resistors – complex, costly but superior.

These metal electrode leadless face resistors have excellent accuracy, stability, reliability, and pulse load capability. They provide optimal power rating and pulse load capability. They show some of the lowest noise and distortion of any resistor available in the market, period.

muRata control-type, low-ESR high-Q multi-layer capacitors. The ‘ESR control’ aspect of the Murata is something special. Their noise suppression abilities are impressive.

Texas Instruments low-noise ICs offer great unity-gain bandwidth, very low noise and distortion, high output drive capability, Common-mode and Power Supply Rejection Ratios of over 100 dB, wide maximum-output-swing bandwidths and high slew rates.