iFi iDSD Diablo X DAC and Headphone Amplifier

Portable Head Amp and DAC Designed for Purists

With its sleek new design and fiery red finish, the iDSD Diablo sits proudly at the top of iFi Audio's portable/transportable DAC/amps. It is built for purists – for the true headphone enthusiast who craves pure, unadulterated sonic performance.

Just like a racing car designed for uncompromising speed, the iDSD Diablo sets aside sonic tailoring as well as Bluetooth connectivity to focus on pure sonic power. Prepare for a riveting ride as it will drive any headphone on the planet with aplomb. Put simply, the iDSD Diablo is iFi Audio's best ever transportable amplifier designed to deliver reference level sound.

‘Bit-Perfectly’ Wicked

iFi uses two Burr-Brown DAC chips and the new 16-core XMOS chip to process the data received via the USB and S/PDIF digital inputs. This means the iDSD Diablo can handle up to PCM 768, DSD 512, 2xDXD. Both PCM and DSD remain ‘bit-perfect’. It also provides full MQA decoding! And with MQA now available over S/PDIF, you can take advantage of any MQA CDs in your collection.

Positively Pure

Balanced, differential analog circuit design reduces noise and crosstalk within the signal path by fully separating the left and right channels. The iDSD Diablo benefits from further refinements to iFi's balanced, symmetrical dual-mono topologies with short, direct signal paths. iFi calls this PureWave. 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.

What's OptimaLoop, you may be asking. 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.

iFi recognized that different parts of a circuit benefit from specifically optimized feedback loops and 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 optimized for a particular function and working synergistically with the others to deliver optimal overall performance.

Diabolically Dynamic

Able to drive all manner of headphones with ease, the iDSD Diablo delivers up to 5000mW of prodigious power, propulsive energy and engaging dynamics, coupled with a remarkable ability to resolve fine texture and detail.

With three settings, you can adjust power and gain to suit your daily driver or track day supercar! TURBO ramps up the level of drive for current-hungry headphones, NORMAL is intended for most over-the-ear or on-ear headphones. ECO dials down the power to suit high-sensitivity in-ear monitors.

Power That Does Not Corrupt

The iDSD Diablo’s focus 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.

These issues are fully tackled by the iDSD Diablo’s design. In order to make less efficient headphones, like planar magnetics, sing, the voltage needs to be stepped up from 3.7V to +/- 15V. We use 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.

Formula 1, iFi Style

High-bandwidth power supply circuity is dedicated to each critical part of the iDSD Diablo’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 digital noise) has separate regulation, too.

Burr-Brown True Native Chipset

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.

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

The XMOS 16-Core chip processes the audio data received via the USB and S/PDIF digital inputs. This new low-latency XMOS microcontroller has greatly enhanced processing power. Compared to the current generation of eight-core chips, this new 16-core IC delivers double the clock speed (2000MIPS) and four times the memory (512KB), as well as the latest SuperSpeed USB standard.

iFi’s in-house digital development team has programmed the XMOS firmware to optimize sound quality and ensure a perfect partnership with the Burr-Brown DAC.

Hooking Up

At the front of the unit, alongside a standard 1/4" (6.3mm) single-ended headphone jack, resides a 4.4mm Pentaconn 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 Pentaconn balanced output to connect to an external amp.

Accessories Galore

As befits a reference-level product, iFi included a whole host of accessories in a luxurious travel case. As the iDSD Diablo may be powered from AC as well as by its built-in battery, iFi included its super silent, noise-cancelling iPower 5V AC/DC adapter to ensure optimal sound quality.

Also included is a 4.4mm Pentaconn to twin XLR balanced interconnect cable to connect the iDSD Diablo to an amp and speakers (or a pair of active speakers) with balanced XLR inputs.

iFi also added a short (15cm) USB-C to USB-A audio cable, as well as an extension cable plus a USB-C charging cable and an adapter to connect headphones with a 3.5mm jack to the 6.3mm single-ended output.