IFi Audio – Micro IDSD Diablo X – Portable DAC/Amp W/ XMEMS Support

iFi Audio – Micro iDSD Diablo X – Portable DAC/Amp w/ xMEMS Support

Diablo X is the very first DAC/amp in the world to drive xMEMS technology.

The Diablo-X is the first DAC/amp on the market to support the revolutionary xMEMS‘ solid state monolithic speaker technology. 

This unique technology features:

• Ultra-fast mechanical response (~15µsec; 150x faster than a typical dynamic driver)
• Flat 2° phase response for more accurate sound reproduction
• +/- 1° phase matching (part-to-part) for more accurate spatial sound
• Silicon speaker diaphragm (95x more stiff/rigid than plastic) for reduce speaker break-up (less muddy mids/highs)

The xMEMS microspeaker technology uses the piezoelectonic effect to create a paper-thin solid-state speaker. These micro-speakers offer great potential to push the boundaries of IEM and headphone performance. As xMEMS themselves say, “The inverse piezoelectric effect is created by applying electrical voltage to make the piezoMEMS contract or expand, converting electrical energy to mechanical energy. This energy excites an integrated silicon membrane to move air and generate acoustic sound waves…. xMEMS’ piezoMEMs actuators offer an increased range of movement enabling rich, loud audio”.

The Diablo-X can still also be used with your favorite IEMs/headphones and, just like the original, uses two Burr-Brown DAC chips and the 16-core XMOS chip to process the data received via the USB and S/PDIF digital inputs. This means the Diablo-X can handle up to PCM 768, DSD 512, 2xDXD. Both PCM and DSD remain ‘bit-perfect’. It provides full MQA decoding. Balanced, differential analog circuit design reduces noise and cross-talk within the signal path by fully separating the left and right channels. The Diablo-X includes PureWave tech – refinements to balanced, symmetrical dual-mono topologies with short, direct signal paths. Negative feedback is used in amplifier circuits to compare the output signal with the input signal and correct errors. BUT there are drawbacks. iFi turns the negatives into positives with OptimaLoop. Read more below.

Able to drive all manner of headphones with ease, including those incorporating the new XMEMs tech, the Diablo-X sports fully balanced 4.4mm outputs with 4,100mW of power.

Three modes are used to adjust power and gain.

• xMEMS – use with compatible IEMs/headphones
• Turbo – ramps up the level of drive for current-hungry headphones
• Normal – for most over or on ear headphones

The Diablo-X focuses on pure, unadulterated performance, means much attention has been applied to the power supply circuity. Battery power provides ultra-clean and stable DC current avoiding the issues of mains electricity – dips, spikes and noise-inducing RFI/EMI pollution. BUT there are sonic downsides resulting from low output voltage and inconsistent output impedance as batteries discharge. In order to make less efficient headphones, like planar magnetics, sing, the voltage needs to be stepped up from 3.7V to +/- 15V.  iFi uses a step-up converter running at 1.2MHz – a frequency far beyond audibility that is easier to filter than a typical switch-mode supply, enabling high linearity and ultra-low noise.

High-bandwidth power supply circuity is dedicated to each critical part of the Diablo-X’s design, with independent linear regulation delivering excellent PSRR (Power Supply Rejection Ratio) performance. The headphone amp stage eschews IC regulators in favor of Panasonic OS-CON capacitors, delivering 2320uF between them. The DAC section benefits from an ultra-low-noise regulator with additional passive filtering, reducing high order harmonic distortion and, in turn, jitter. Even the USB input stage benefits from dedicated regulation and multi-stage filtering, and the microprocessor control circuitry (often a local source of noise) has separate regulations, too.

Whether you are using your favorite IEMs/headphones or a pair of xMEMS-compatible IEMs, the Diablo-X connections have you covered. At the front of the unit, alongside a standard 6.3mm single-ended headphone socket, resides a 4.4mm Balanced output for headphones offering balanced connection. At the back are two digital audio inputs: USB-A and a S/PDIF socket that accepts both electrical and optical signals, the former via a 3.5mm connector and the latter via a supplied adapter. The USB-A input features a ‘male’ connector, rather than a typical ‘female’ port for greater mechanical integrity.  A separate USB-C charging port is also provided, along with a 4.4mm Balanced output to connect to an external amp.

 

FEATURES:

• 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.

• The XMOS 16-Core chip processes the audio data received via the USB* digital input.

  This low-latency XMOS microcontroller has greatly enhanced processing power. Compared to the current generation of eight-core chips, this 16-core IC delivers double the clock speed (2000MIPS) and four times the memory (512KB), as well as the latest SuperSpeed USB standard.

• MQA (Master Quality Authenticated) is supported through the USB with full decoding of MQA files up to 384kHz thanks to the processing power of the new 16-core XMOS chip.

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

• Extensive jitter-eradication technologies are applied to the digital stage, including their 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.

• ‘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.

• Balanced, differential analog 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.

• As with many other iFi audio products, they’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.

• 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.

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

• 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 their ESR changes little even at low temperatures since the electrolyte is solid.

• 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.