iFi Audio iDSD Diablo X DAC and Headphone Amplifier

The iFI Audio iDSD Diablo X DAC and headphone amplifier is one of the first headphone amplifiers to support the brand new evolutionary speaker technology called xMEMS which has now entered the headphone market. The xMEMS system creates headphones with an ultra- fast mechanical response as well as a flat phase response. As a result, the sound can be more accurate, with less muddy mids and highs.

Notably, the xMEMS drivers need a higher voltage to operate, hence the Diablo X has a dedicated mode for xMEMS devices. Moreover, The Diablo X uses two high end Burr-Brown DAC chips for maximum performance, as well as a sixteen-core processor. Notably, this is a battery-driven unit with a USB C charging port. Both normal and balanced outputs are provided.

What is xMEMS?

xMEMS is a micro speaker technology that uses the piezoelectric effect to modulate a paper-thin diaphragm. This makes a speaker that is essentially solid state with no moving parts. Notably, piezoelectric elements are used in ceramic phono cartridges. The movement of the stylus flexes a crystal that generates tiny amounts of current. However, this can also be reversed, where a drive current will cause a piezoelectric diaphragm to move. This technology pushes the boundaries of IEM and headphone performance. Notably the diaphragm has a greater range of movement than standard drivers, giving louder audio.

Versatile outputs and a high-end DAC

The Diablo X can still be used to drive any type of headphone and has three output modes. Consequently, it features two Burr-Brown DAC chips as well as a sixteen core XMOS data processor. The data can be obtained from the USB or S/PDIF inputs. Moreover, PCM data rates up to 768kHz are supported as well as DSD 512. MQA is also supported for bit-perfect sound.

Balanced dual mono design

The analogue circuity is based on a dual mono differential amplifier. This reduces cross-talk and noise. There is also PureWave that uses short direct signal paths. Negative feedback is used to compare the output with the input signal. This corrects any errors.

Three output modes

Different headphones need different driver voltages. Hence the iFi audio iDSD Diablo X has three output modes. XMEMS is for use with the new xMEMS IEM’s. Turbo is for use with current hungry headphones and provides more drive. Normal, can be used with most of the more common types of headphones.

Connectivity

There is a 4.4mm balanced output on the back, as well as Inputs including USB and S/PDIF. The front also has a standard 6.3mm headphone socket and another balanced 4.4mm socket. There is a USB C charging port on the back of the unit as well as a standard USB input.

Battery power supply

Having a battery supply makes the unit portable and removes any source of noise. There will be no mains noise or dips in supply. However, a battery supply needs to be carefully designed, to prevent low output voltages and varying voltage impedance, as the battery discharges. Moreover, some current hungry headphones need to run on + / - 15 Volts. This has to be generated using a step up transformer and oscillator. IFi uses a high frequency system that pushes any potential interference out of the audible range.

High performance power supply

Virtually every section of the Diablo X has its own PSU regulation. The headphone amp section does not use IC regulators but relies on OS-CON capacitors, with a capacity of 2320 mFD. Additionally, the DAC section has an ultra-low-noise regulator that has additional passive filtering. This can reduce high order harmonic distortion as well as jitter. Finally, the input stage also has it’s own regulator and multi-stage filtering.