The Ultimate Dynamic Duo!

PROS: D16 – neutral sound tuning with a natural analog tonality, expanded soundstage, 1bit discrete DAC design under a custom FPGA control driving 16 sets of cascaded 8E PWM-DACs in FIR mode, powerful output (up to 1125mW), USB-C/OPT/Coax inputs and PO/LO outputs, easy access to replace the battery; PB5 – adds more analog texture with a smooth natural tonality, very expanded soundstage, dual NuTube fully balanced design, powerful output (1700mW), easy access to replace batteries (6x inside).

CONS: price (both), charging (PB5, 5V only), small toggle switches (both, power/gain), getting used to analog stepped volume attenuator (both, 24-steps), not having a clearly marked volume knob.

These products were provided to me free of charge for the review purpose in exchange for my honest opinion.

Manufacturer website: iBasso D16 and PB5.  Available for sale directly or authorized retailers like Bloom Audio D16 and PB5.

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Intro.

As I already mentioned in a number of my reviews, AKM factory fire from 2020 was both a curse and a blessing for audio manufacturers, challenging them to get more creative with custom DAC implementations after realizing they can’t always rely on the latest off-the-shelf chips.  Since then, we have seen more designs using custom FPGAs and discrete DACs, from R2R ladder to 1bit DSD and PWM applications.  And while iBasso wasn’t a stranger to in-house developed FPGA-Master solution in their flagship DAP designs, to my surprise they were not in a rush with discrete DAC designs, at least not until now.

At the end of last year, iBasso teased us with a lot of new upcoming releases, and I already had a chance to test and to review their DC Elite mega-dongle.  After that, more showed up at my doorsteps, including DX260 DAP, 3T-154 IEMs, D16 DAC/amp, and PB5 amp.  The focus of today’s review is going to be on the almighty duo of D16 and PB5 both of which ended up being a very pleasant surprise.  Instead of placing of everything under the hood of a single DAP, iBasso partitioned it into a separate discrete DAC/amp with a newly updated FPGA-Master 2.0 and a separate dual NuTube balanced amp.

After spending over a month with both of these devices, testing them in different combinations, and realizing how well they play together and with other audio gear, I decided to write a combined review of D16 and PB5.  Here is what I found.

Unboxing and Accessories.

The unboxing experience of both of these devices is quite similar.  They both arrived in a similar larger size premium quality giftboxes inside of an all-black plain carboard sleeve.  Each one houses corresponding devices inside of a soft leather drawstring pouch and accessories inside of another velour draw-string pouch.  Both had similar green leather wrap-around cases with a metal perforated back.  These cases enable full view of the display (D16) and dual NuTubes (PB5).  The wrap around case design is secured with a velcro flap on the side, providing the full access to headphone ports and the volume control on the front, and charging ports, toggle switches and coax port (D16) on the back.

Along with PB5 you will get 2x balanced interconnect cables, a short (3.5” cable) and a long (12”), each one with chunky machined metal housing 4.4mm connectors, the same one as in their IT05 IEMs cable.  The connector housing itself looks and feels like a hardware analog knob, hefty and durable.  Personally, I think it was a great idea to provide interconnect cables in different lengths since you never know how close you are going to be to the source.  You will also get a high-quality USB-A to USB-C charging cable, a warranty card, and a quick start guide.  It is not as easy to read since the print is grey on black, but do pay attention to the guide, especially since you can only use 5V USB-C charging supply with PB5 amp.

In addition to its own USB-A to USB-C quality charging cable, D16 comes with a set of interconnect cables, including USB-C to USB-C OTG cable for use with Android phones or other devices, like the new iPhone or laptops, that utilize USB-C connector.  For the users of “older” iPhones, also included was USB-C to Lightning OTG cable.  These IC cables are braided, separating power and data signals to minimize the interference, and they use high purity silver-plated copper wires.  You also get a short Digital Coax cable with mini connectors.  My review sample included both, one with braided silver-plated copper wires and another one with a combined thicker cable inside of a sleeve, similar to the ones iBasso includes with their upper end DAPs.  A warranty card and a quick start guide was provided, the same silver-on-black print which is not easy to read.  And keep in mind, digital volume smaller knob functionality wasn’t mentioned in there as “volume control”, but rather referred to as Selector Switch to access internal settings.

Page 2 – Design and under the hood.
Page 3 – Sound Analysis and Pair up.
Page 4 – Comparison, Source pair up, and Conclusion.