iBasso DX340

When it comes to music playback, DX340 doesn't differentiate between CD rips, Hi-Res downloads and Android streaming. It upconverts all your normal PCM material into DSD before decoding your digital to analog. All formats are passed as DSD through DX340’s 1-bit decode. 

Without irony, DX340 will yield the most improvement to collectors of SACD-rip, DSD64 files. As a heavily-upsampling DAC, iBasso take the honours as one of the first Head-Fi products to target and remove DSD64's terrible ultrasonic noise problems.

iBasso build a 1-bit DSD DAC into DX340 because there's zero error at the point of conversion. There, DX340 relies on the total accuracy of DSD's 1-bit conversion to analog, taking advantage of DSD's sheer ease of decoding to boot.

The pitch for DSD's 1-bit conversion is digital at its simplest and closest point to analog – level represented only either as a 1 or a 0, switching on or off. 

To achieve analog, the bitstream is simply low-pass filtered. But there's work DX340 needs to do first, preparing incoming DSD and certainly PCM data aboard your player to emerge as the best possible 1-bit digital stream for conversion. 

How DX340 alleviates said white noise issues of DSD64 – indeed, of any inherent problems to single-rate material be it DSD's noise or PCM's steep digital filtering, intersample overs and digital pre-emphasis – is that it applies heavy oversampling to incoming data.

iBasso's DSP oversamples data to huge bit depth and sample rates synchronous to their new FPGA-Master 3 generating I2S. The new multibit data running many times DSD's base 2.8Mhz rate is then put through a Pulse-Width Modulated (PWM) process in preparation for 1-bit decoding.

iBasso treats each of DX340's 32 resistors per DAC phase as individual entities, operating them at very specific moments in the time domain. 

Ordinarily that might spell chaos co-ordinating a total count of 128 individual DAC elements, but it's iBasso's FPGA-Master 3 that grants a firm grip of how each resistor-capacitor low-pass filter outputs in the time and frequency domain.

The result of the entirety of 128 DAC elements outputting at phased intervals leads to a coherent, continuous waveform with finer stairsteps in time. That captures more detail in your music and reduces errors, decoding your music back more accurately to the original waveform.

DX340's PWM DSP pre-stage addresses the problems of conventional noise-shaped digital's inconsistent rise and fall edges at the frequency level, with adjustments made to facilitate more accurate, predictable switching.

This approach results in a reduction of errors by avoiding intersymbol interference. Notably, non-linearities arising from rise and fall mismatches do not manifest as total harmonic distortion. iBasso's PWM DSP does not produce harmonic errors that vary with digital output levels. 

And the processing power FPGA-Master 3 possesses allows listeners to experiment with digital harmonic distortion profiles in real-time. Dubbed 'Advanced Harmonic Adjustment', DX340 owners can switch between adding even-order harmonics – for smoother and more liquid sound – or odd-order harmonics – for greater dynamics and harder impact. Instant synergies with your headgear can be discovered in this way.

Aboard DX340's logic is a digital volume control with large coefficients to trim levels and add datastream width. This high bit and sample rate headroom is free from overload issues when it is eventually brought back down to the required 1-bit DSD signal for low-pass filtered conversion – but now at a bandwidth of 49Mhz, moving DSD's white noise issues far, far out of the audible band.

iBasso's discrete proprietary tech immediately differentiates itself from commercial DAC chips, where IC packages are often too small to perform an ideal 1-bit DSD conversion. DX340 also avoids the errors of dynamic element matching inherent to 2-7 bit delta-sigma decoders.

This high-fidelity is amplified and flows on to DX340's Amp15 and powerful op-amp output buffers that supply current and mean iBasso's flagship promises high damping factor while maintaining its low distortion into low impedances typical of IEMs, Focals, Fostexs and Rosson Audio Designs.

Specially selected by iBasso, DX340 boasts eight Texas Instrument devices that are ideal voltage sources and stable into capacitive loads, with their gain bandwidth product ensuring frequency response extends well beyond the human hearing range for excellent phase response and taut, impactful and life-like dynamics.

Still the closed-loop internal gain remaining after the mandatory application of negative feedback around iBasso's analog circuit remains high, so where she really can shine is in swinging voltage, opening up the sound of any high-impedance Audio-Technica, Sennheiser and ZMF Headphones while barely breaking sweat.

But where DX340 exceeds all others who use this TI buffer is its ability to accept a 12 volt DC input into Amp15, bypassing its battery and internal 8 volt rails to increase headroom and linearity, directly boosting the amount of swing DX340 is capable of. 

With Desktop Mode activated by inserting said DC power supply, Amp15 is capable of outputting over 2 watts per channel, effortlessly running big headphones at the desk! But discrete audio amplification will always still have its day, and previous owners of the DX300, DX320 and their relevant amplifier cards are not left hung out to dry. 

Amps 12 thru 14 are adaptable to DX340's new structural housing via card adapters, meaning you can enjoy Amp12's discrete current-handling and reduced feedback of such topologies with the most demanding low-impedance flagship IEMs around today.

While the Nutube gain stages of Amp13 and Amp14 can also transfer their lush goodness to DX340 as you await Amp16 thru 18, currently in 2025's pipeline.

Away from the desk, you'll enjoy clean power for whichever card you load up, with separate battery systems – one for digital and one for analog circuits – meaning you'll never risk one side dirtying the other.

This battle against obsolescence through swappable amp cards and dual batteries is aided by DX340's enclosure being easy for you to access and change any parts that you need, without returning to the factory. 

iBasso's future-proofing is complete with the loading of Android 13 aboard a Snapdragon 665 SOC backed by 8GB of RAM. And a coaxial output also means DX340's FPGA-Master 3 makes for a wonderful source with iBasso's own D16 and D17, should you want to stack

DX340 is the pinnacle of iBasso engineering, a testament to how far they've brought Head-Fi. If you seek other simpler DAC and DAP solutions, check out iBasso's other releases here, or view our other music players here.