Return of the classic!

PROS: ability to finetune DX240 sound, adds 4.4mm PO to DX240 and 3.5mm PO to AMP8, discrete balanced design, high power (voltage/current) output.

CONS: additional cost, PO only.

The product was provided to me free of charge for the review purpose in exchange for my honest opinion.

Manufacturer website: iBasso.  Available for sale directly or retailers like Bloom Audio.

iBasso DX240 DAP review.

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Intro.

It’s not the first time I mentioned this, but DX240 announcement did take me by surprise!  Aside from their MAX series, modular DX220 used to be iBasso’s flagship DAP until it got replaced by a modular DX300.  Between their flagship DX300, mid-fi DX160, and DC-series usb DAC/amp dongles, iBasso has a lot of ground covered with sources for every need.  Then, out of the blue comes DX240 which raised a question if you should get DX240 or DX300, and should you still consider it if you already have DX300?

It made perfect sense for those who accumulated various amp modules during their time with either DX150, DX200, or DX220 DAPs since you can continue using it in DX240 with a faceplate conversion kit.  Plus, DX240 has a smaller footprint than DX300 and runs the same optimized Android 9 with a fast Snapdragon 660 SoC.  To me, with all the previously released modules, the one which stood out the most was AMP8 with its discrete balanced design that got implemented in stock DX300 amp module as well.

That original AMP8 with 4.4mm PO came in handy since DX240 stock AMP1mk3 only has room for 2.5mm BAL output, though AMP8 doesn’t have 3.5mm.  But not everybody has AMP8 to begin with or will buy it just to convert for DX240.  So, per request of their customers, iBasso responded with AMP8mk2, already assembled for use with DX240 without a need to convert anything.  But is this just an AMP8 with an added bonus of 3.5mm output or more?  After spending a few weeks with this module, here is what I found.

Unboxing and Accessories.

Unboxing experience is rather basic but still noteworthy so you are aware what to expect.  The product arrived in a small cardboard box with a secure foam insert holding the amp card in ESD bag, screwdriver, extra set of screws, quick start guide, and a warranty card.  Screws are very small and easy to lose when taking the card out, thus a spare set is a welcome addition.  Hex screwdriver is important too, not everybody has a full set of hex bits.  Quick start guide provides a guidance to removal and replacement of the card.  And, don’t discard ESD bag.  Unlike enclosed amp modules for DX150/200/220, DX240 and DX300 amp cards have open printed wiring board (pwb) which you need to keep in ESD bag.  Once you remove stock AMP1mk3, store it in that bag.

I already mentioned in the Intro about faceplate conversion kit.  It is available as an optional accessory.  You can request it from iBasso or your local retailer.  Since the actual amp card pwb is the same between DX150/200/220/240, you can take it out of amp1-amp8 modules and ‘convert’ by attaching DX240 card faceplate to it.

Another optional accessory which I recommend is a leather case.  DX240 comes with a silicone TPU case, a nice transparent case that wraps around the DAP.  But the leather case gives DX240 a more premium look.  The DAP slides in from the top, the case wraps around it like a glove with a top open to access coax and usb-c ports, bottom has cutout for headphone ports, transport buttons are covered on the right side with the volume wheel just above it with easy access.  MicroSD card is covered, and you will have to slide out the DAP to remove it.  Also, along the length of the curved DX240 back, the leather case has two parallel bumpers, to enhance the grip and to prevent it from rocking when placed on the surface.

Under the hood.

AMP8mk2 follows the same discrete balanced amplifier design as the original AMP8.  To achieve both high voltage and high current output in order to satisfy the needs of everything from lower impedance hybrid IEMs to higher impedance more demanding headphones, iBasso decided to use discrete components, typical of desktop amplifiers.  As a result, opamps they choose allows it to reach max +/-8V high voltage swing, while the transistor output buffer stage ensures sourcing of 2000mA output current.

AMP8

AMP8mk2

The spec is quite impressive, 4.4mm BAL output voltage 6.2Vrms, 0.55ohm output impedance, and power rating under load of 980mW @32ohm and 128mW @300ohm.  The single ended 3.5mm output scales it down to 3.1Vrms, 0.32ohm output impedance, and power rating under load of 281mW @32ohm and 32mW @300ohm.

On paper, this is a similar power output spec as the stock AMP1mk3 card, but now you are also getting 4.4mm PO output.  And, relative to the original AMP8 card, you are also getting 3.5mm PO.

I’m sure some might be wondering about the effect of AMP8mk2 card on battery life of DX240.  I ran multiple tests, connected to 4.4mm BAL output in high gain, playing flac files in the loop at a normal listening level with wifi/BT off and periodically turning the display on to check the battery status.  Under these test conditions I was getting around 10hrs of playback time.

Page 2 – Sound analysis and Comparison.
Page 3 – Pair up analysis and Conclusion.