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.