Mike Piskor 2015

Objective2 USB DAC & Amplifier Rev.B by Mayflower


The O2 has never been about boosting or exaggeration, quite the opposite.  The parties involved in the unit’s creation have specifically selected parts that offered the least amount of distortion and color to the sound signature as possible…and they really succeeded.  If you are into the musicality end of the spectrum and plan on using nothing but the O2 for your Amp and source for your computer, then you should skip this product and latch onto something else known for introducing more tonal hues into the experience.

This O2 is dead neutral in tone, flat and absent any noticeable boosting from top to bottom.  Bass, mids and treble are setup perfectly in line and no section of the sonic spectrum is bloomed outward or inward, no forward mids and no V-shape here.  This is ideal if you want to pair your O2 with a variety of external amplifiers in your audio chain, as the flat sound will mesh with the majority of individual amplifiers, all while never intruding on the amplifiers physical sound setup.  Summed up, the flat sound of the O2 will not pair poorly with an amplifier that may offer boosted bass or midrange.  You’ll want a flat sounding first link in the chain, so to speak.

The low end is pristine in clarity, but almost totally void of any noticeable texture.  I am not fond of it and it does not pair with my personal Summit-Fi rig that is composed of an Edition 5 from Ultrasone, a Noble K10 ciem and a Stax 007.  When used as the primary DAC for my rig, the O2 is probably one of the last products I would want to use, but that is due entirely to sound signature preferences and the lack of substance offered.  I very much prefer the low end of my portable players, especially the iBasso DX90 Rockbox OS, which allows me to intricately configure the bass to my heart’s content.  I actually cannot achieve the level of Bass EQing on the PC with foobar2000 in comparison to the DX90 and because of that reason; I vastly prefer to listen to my Edition 5 straight out of my DX90, instead of the O2.

Clarity is not an issue, but the lack of musicality is going to upset chasers of exaggerated and fun tone, but of course will make critical listeners jump for joy.  If you bought the O2, you should have already been aware that it isn’t ever going to exaggerate anything, so the lack of musical tonal offerings is something you should be well aware to be absent before you purchase.  As mentioned, the O2 is all about critical accuracy , so those who own some of the more musical rigs out there may want to start eyeballing something else.

However, if you are a purist and enjoy unadulterated, crystalline-like tonality and cleanliness, there is literally nothing else on the market that will achieve that as well as the O2.  For those who love that type of a sound, this is your Mecca.  Feel grand in knowing there is almost nothing else for the price that achieves clarity in the bass and midrange on this level and for such a low price.

One quality that bugs me is that the O2 is quite unforgiving at times and can be a bit fatiguing with slam effect, especially on the bass end.  When I plug something like my Grado GH1 or my K-10 ciems into the O2, I am usually met with a lacking bass experience, one that I find to be overly slamming and impactful.  Certainly, the DX90 and the Modi from Schiit are noticeably softer and yummier with physical impact factor by a small degree.


Mids and Treble

The O2 really isn’t geared for usage with headphones or amplifiers with midrange pop or sparkle; you’ll not achieve an acceptable sound signature with the more mid-forward rigs out yonder.  Is that a downfall? Not really.  The O2 is plenty fabulous when it comes down to raw clarity, but an intimate sounding amp and DAC this O2 is not.  So, be prepared for the linear feel of the O2 if you still purchase it for usage with your pro-vocalist experience headphone, otherwise you’ll feel let down by the flat, physical setup the O2 offers at all times.

Tracks from Earth Wind and Fire’s DSD-64 remaster, via www.acousticsounds.com, are reiterated in a manner that I am not fond of when plugging most of my headphones directly into the O2 and ignoring external-secondary amplification.  Straight out of the O2, I find most headphones to sound extremely neutral and lacking a sense of wonder and enchantment from top to bottom.  A few models that I currently have on hand pair well, specifically the mid-tier headphones like the Fidelio X2 and the PS500e.  These models seem to not be bothered by a flat source and change little when I add my Aurium amplifier into the mix, which is something I found to be unnerving to say the very least.

With regard to clarity, the O2 has an abundance of purity, but lacks the dynamic density that I would want to do the more recently slew of great headphones justice.  Most of them have ditched the thinner sound signature and have opted for a heftier, weighted signature in recent times.  This is why I prefer the DX90 in DAC mode for most of my headphones and despite the O2’s audible superiority in clarity.  I’ll make that sacrifice for density and subject the rig to a lacking clarity experience for it without a second though.  That tends to happen when I am connecting a DAC to my more upper end amplifiers where the difference in clarity between the DX90 and the O2 is almost indistinguishably cleaned up by the more expensive amplifier.  That lacking solidity factor of the O2 leaves me wanting, but satisfies me twice over with clarity needs where most other DAC’s in the tier do not.

The treble of the Mayflower O2 is extremely unforgiving at times and through certain headphones.  That purity and clinical appeal the O2 streams out in droves really shines here in a positive way if you are critical listener, so no worries if you wanted something that stays very true to the source track…but also be prepared for a sibilant experience at times.  That isn’t the fault of the O2 in the slightest, but it is the fault of the track quality or poor recording and how nicely the O2 copy and pastes the micro details back towards you.  Tracks that are nicely recorded and smooth will sound as such, tracks with a nasty treble experience or a poorly rendered recording will be fatiguing to listen to.  Again, that is the cost of having one of the most pure and exaggeration free amplifiers and USB DAC’s on the market, the O2 does that better than most, if not all other competitors in the price tier.

Sound Stage

Ah, the weak link in the chain and the O2’s kryptonite: the imaging.  Sadly, the O2 isn’t at all special when it comes to sound stage vastness in width, height or depth of field.  There are certainly lesser expensive models from other companies that compare and even best the O2 in this area, so you might not feel so happy when you come to find your HD700, X2 or similar not sounding up to par in terms of stereo imaging prowess.  There is a noticeable difference of depth of field when I compared the O2 to my DX90 in DAC mode, the latter of those two having more detailing in the stage depth, whereas the O2 sounded closed in.

I can’t really fault the O2 for not being very spacious, I think that would negate the idea of what the O2 was all about: to not exaggerate and be as distortion free as possible.  Very spacious sources tend to lose intimacy factor and can sound slightly stretched in an unnatural manner, so maybe it was very wise of Mayflower to opt for components that didn’t offer too much of a good thing here.  The O2 certainly sounds more aired out than the Schiit Modi and Magni combo, but I don’t really detect any differences in height or width factor between the two.  Both sound good in this regard, but neither sound great or special when it comes to sound staging in general.

Final Thoughts

Of course, the O2 remains the best DAC and amplifier under $300 or so.  Neigh untouchable in clarity, extremely versatile and lacking very little, Mayflowers powerhouse combo pack really hits home and offers exceptional price to performance value.  I’d like to see a future revision with some thought for musicality lovers like myself and those who chase the exaggeration rabbit, so to speak.  I would like a thicker substance factor to the entire presentation, something heftier and weighted, but also less impactful and much more yummy-smooth.  I think the O2 already has the critical listeners market cornered for this price tier and most seem to be aware that this product was intended to be as distortion free as possible.  That’s great for those listeners, but what about the others who just want to rock out?  I hope Mayflower offers a Revision C-version to the O2 that is specifically tailored to offer a more fun and whimsical experience, something very exaggerated and soothing.


At the end of the day, the O2 blew my mind with the raw clarity it was able to achieve.  Seriously, I use the O2 as my DAC > Stax SRS MK2 amplifier (which is only $400 or so) and with the Stax 007 in the mix.  How often can you say a sub $300 DAC/amp combo can be justified for usage with one of the most high end headphones out there?  The O2 also sounds magnificent through the Ultrasone Edition 5 when the track happens to be very well recorded and smooth, dare I say sublime and jaw dropping.  The experience sounded eerily similar to the hyper expensive Cavalli Liquid Lightning 2 + 007 right that I’d reviewed a while back, which is an amplifier that is in the multi-thousand dollar tier and that was combined with a very expensive DAC during the review of said Cavalli amplifier.  There are also times where I prefer to use the O2 straight up and without connection to my Pathos Aurium amplifier.  I’ve never said such a thing about any DAC before.  Jeez.

Great job, Mayflower!  Hell of a product!

Price: $274.95

Links: https://www.mayflowerelectronics.com/shop/digital-to-analog-converters/objective2-odac-combo-with-rear-power/

Technical Specifications

Frequency response 20-20kHz +/-0.14dB +/-0.04dB
THD+N 100Hz -0.15dBFS 0.0022% 0.0013%
THD+N 20 Hz -0.15dBFS 0.0017% 0.0015%
THD+N 10Khz -0.15dBFS 0.0056% 0.0024%
IMD CCIF 19/20 Khz -6.03 dBFS 24/96k 0.0027% 0.0005%
IMD SMPTE -6.03 dBFS 24/96k 0.0008% 0.0008%
Noise A-weighted -102dB -103dB
Dynamic Range A-weighted >111dB >112dB
Dynamic Range (un-weighted) >107 dB >109dB
Linearity -90 dBFS -0.09dB -0.08dB
Crosstalk 1kHz, – 10dBFS (3.5mm jack) -80.4dB -86.4dB
USB Jitter 11025 hz 100K -105.8dB -112.3dB
Output voltage 100K 2.0Vrms 2.1Vrms
USB controller TE7022L SA9023
DAC ES9023A PCM5102A

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