In the experiment with iFi Audio iDSD Diablo: A ridiculously great headphone amplifier

Among the portable headphone amplifiers in the iFi Audio iDSD Diablo range, there is no frills; just power, power, and more power.

Text: Heikki Kivelä
Photos: Manufacturer & Heikki Kivelä

In iFi Audio’s extensive lineup of portable audio amplifiers, the Brittimerkki brand has five different models with various features, and at the top of the lineup is the brand new flagship product we tested, the hefty red iDSD Diablo, priced at 999 euros.

On the surface, the iDSD Diablo looks quite restrained (apart from the color), but its appearance should not mislead you. It is compact in size like other iFi Audio Micro iDSD devices, features a built-in 4,800 mAh battery that offers six hours of wireless playback, and includes components and connections that deliver uncompromising power.

As if it were a sports car, the iDSD Diablo has been stripped of all the superfluous elements. Instead of complex adjustments and even Bluetooth connectivity, it offers practically nothing extra; the focus is solely on sound quality performance. The starting point is that the iDSD Diablo can drive practically any headphones while wearing the ground, either with an unbalanced 6.3 mm connection or a balanced 4.4 mm connection. As for media connections, there is USB and spdif available. There is also a balanced 4.4 mm plug with fixed volume control included.
Exceptionally, the iDSD Diablon USB connection has been implemented with a male connector. According to the manufacturer, this arrangement enables better mechanical connection, and at the same time, for example, iPhone and iPad users can connect their devices to the iDSD Diablo directly using the Lightning to USB Camera Adapter. In this way, the device is suitable for use with not only computers but also smart devices.

Power under the hood
Inside the bold red shell, the signal conversion is handled by two Burr-Brown da converters in a custom configuration, which iFin says enables truly low-level noise, improved channel separation, and the reproduction of even the finest sound details and microdynamics.

In accordance with modern standards, the iDSD Diablo naturally supports high-resolution audio. On the PCM side, the maximum resolution is stated to be 32 bits and 768 kilohertz, and the device can also play back dsd512 as well as single and double dxd. Thanks to the four-channel True Native implementation from Burr-Brown, the PCM and dsd data travel along different paths within the device. This means that not only dsd but also PCM data remains in the so-called bit-perfect format throughout the analog conversion. In addition, the iDSD Diablo also handles the playback of mqa material found on Tidal, among other things. The device decodes this properly and hardware-basedly, and it does not function merely as a mqa renderer.
The digital side’s expertise is only one half of the equation when it comes to iDSD Diabolos; equally important is its function as an analog headphone amplifier. The amplifier side is implemented entirely balanced within the device, which in turn explains the high price of iDSD Diabolos.

According to its manufacturer’s promise, the iDSD Diablo can indeed drive all possible headphones, such as sensitive in-ear buds or power-hungry flat-earphones, without any problems. The user can adjust the headphone output gain to the most suitable shape for their headphones using a three-way connection: the Turbo setting is intended for power-demanding models, while the Eco setting is better suited for more sensitive in-ear models and also serves as a power saver, and the Normal setting is a mid-ground between the two above.

When it comes to performance, the Diablon balanced headphone output delivers 12.6 volts / 4,980 milliwatts at 32 ohms and 19.2 volts / 611 milliwatts at 600 ohms, while the unbalanced output delivers 8.8 volts / 2,417 milliwatts at 32 ohms and 9.6 volts / 153 milliwatts at 600 ohms.

Audio inputs are found via optical and USB, while the output has a fixed 4.4mm balanced Pentacon connector with volume control. There is also the same connection on the front for adjustable volume for headphones, as well as the traditional 6.3mm output.