Review of the Objective 2 + ODAC Combo Desktop version by Mayflower Electronics

[h264]

 

Background:

For those who have never heard of this funny-looking piece of electronics, the O2 is a headphone amplifier designed and tested by the mysterious NwAvGuy. He ran a blog called - not surprisingly - http://www.nwavguy.com, which is one part explanation of the electronics of modern headphone audio, one part extremely sophisticated scientific measurements and reviews, and one part rant against the state of modern audio. As a clearly knowledgeable and experienced electrical engineer, he tore apart a couple of well-respected boutique, consumer, and DIY amplifiers, and showed through measurements that the official manufacturer specs were not only wrong but in a certain instance theoretically impossible. Of course, the blowback from these revelations was nothing short of impressive (think AMD vs. Intel). All of this eventually led to a challenge from one said DIY headphone designer:  "Where's your amp?"
The resulting design was an AC and Battery powered "portable" DIY design driven by two 50 cent OP-AMPs and featuring a simple dual gain switch and all the inputs and outputs on one side, with no other bells and whistles attached. Complete with case, the total cost came to about $150. The amplifier was built more as a proof of concept than as a ground breaking design. In fact, it was meant to be quite the opposite of ground breaking. It focused on basic design principals, leaving out exoteric circuitry and fancy components, and exclusively used measurements to iron out its design flaws, a major departure from the design by ear method that had dominated until this point, at least in the boutique amplifier community. What was ground breaking about this amplifier, was that the ENTIRE design process was posted on his site, from the original measurable goals to the testing, measurements, and finished design. As a result, the O2 is an open source design that is among the most tested and documented pieces of audio electronics on the web.

The Objective Digital to Analog Convertor, or ODAC, which makes this unit in effect an external sound card, sits in where the batteries would fit in the original O2. Also designed by NwAvGuy, it features a standard class 1 USB interface with a mini-USB input, which works on Windows and MAC out of the box without drivers. It outputs in 24bits and 96Khz sampling. It's exceedingly simple. Only USB power is required to push a standard 2VRMS output. No optical. No SPI/DF. Mine specifically has an optional RCA output on the back for routing to an alternate amplifier. The completed circuit board retails for $99 w/o a case.
The fact that this design is DIY gives a lot of room for interpretation. If you browse the larger audio forums on the web you'll certainly see some very interesting enclosure designs. The only design alternative specifically mentioned by NwAvGuy was the desktop version of the O2. This was not the vaporware Objective Desktop Amp, or ODA, he mentioned shortly before his disappearance, but the O2 in a slightly larger case with a ¼" headphone jack, the ODAC, and no batteries.
This Desktop O2+ODAC combo was made with parts from JDSLabs and built by Tyler of the one-man shop known as Mayflower Electronics.  He has previously sold on ebay and recently opened his own web site http://www.mayflowerelectronics.com. He differs from the primary distributor JDSLabs in that he offers a bit more variety in the color of enclosures and front panels offered, and also offers a few different volume knobs. The biggest difference is the Desktop O2 he has started selling recently with and without the ODAC.

 

NOTE: ONLY MAYFLOWER ELECTRONICS BUILDS THIS VERSION.

Impressions:

Packaging:



It's your standard fair for eBay, the AC adapter and cable are lose and the O2 itself is wrap in copious amount of bubble wrap. I like bubble wrap, and it protects the O2 well since I'm sure it was sliding all over this USPS bulk shipping box.


The O2 itself comes wrapped in an anti-static bag with Tyler's business card, just like the JDSLabs O2, which I also own (Although it's John Seaber's card instead, of course).

Construction:

This is the most important section because the one thing you CAN'T screw up is the build of the actual unit. If it's not to spec, it's simply not an O2. As with computer systems, implementation is everything here. And if you don't intend to read down, I can say that the internals are exactly to spec on this unit.
Intentionally left out are two of the battery contacts, with the other two left in to hold the ODAC in place, as well as the 1/8†headphone jack. This version replaces this with a panel mounted ¼" headphone jack, which takes the place as the ground contact on the unit. Sturdy yet flexible silver cabling is soldered to the jack and the internal connection between the ODAC and the O2. The components are more neatly soldered into the board than my standard JDSLabs O2, but it's not like it matters unless you create a short with the solder. Overall, inside is a good job.
Unfortunately, the outside is the issue with this amp. If you notice from the first image at the top, the printing on the outside of the unit is off to the right by about 30mm. It's not terrible, but it's definitely noticeable around the volume knob. From the pictures taken on his site you can see another front panel that's too high, one off to the right like mine, and one too low. I think there's something wrong with the laser etcher and aligning the panels correctly on it. I've contacted Tyler to see if can get a replacement, so we'll see what happens on that front. UPDATE: It's been fixed, thanks Tyler!.  Also the volume knob itself fell off the O2 when I pulled it out of the static bag. I've taken my other O2 apart a couple of times so I had the Allen wrench handy to re-tighten it to the shaft, but I wish he'd spent the 2 minutes to do it himself. It's nice that I can use a slightly larger Allen wrench on the screws for the front and back panel. I've about ruined the screws on my JDSLabs O2. The back where the ODAC resides is perfect, the RCA jacks and all. As for the black powder-coated finish, there is finally a design that doesn't pick up fingerprints and dirt and looks professional at the same time.

Audio Impressions

However, I'm not sending it back, warts and all, since this is perfect for what it does, which is drive headphones in an extremely small package on my desk. It goes without saying I hear zero difference between my JDSLabs O2 and this version.
So much has already been said about the O2's sound quality or lack thereof that I'll leave it up to a curious reader to discover that amplifiers don't sound like anything at all, unless they have tubes, high output impedances, or have lots of noise. Ideally, they increase the decibel output of your headphone to acceptable levels without adding too much noise, hiss, or distortion. After all, it's the headphones at the end of the chain that produce the sound waves your ears hear, and the DAC at the beginning that decodes the digital file into an analog signal. You won't hear that on forums like Head-Fi, however, as their $3500 amps of course sound better than mine. Despite an impressive set of measurements I constantly hear things like:
-It's not powerful enough. My orthodynamic/planar-magnetic headphones lack impact and sound thin.
http://www.headfonia.com/nwavguys-objective-2-by-jdslabs-and-epiphany-acoustics/2/
There are no words. None. This whole page is the biggest single biggest stream of consciousness I've seen pertaining to an audio product in a while. It goes around in a big circle like a ride at a waterpark. Except, the waterpark is much more fun. And I'm better at stream of consciousness.
-It's got too much noise at high gain. My headphones don't get loud enough at low gain even with my fancy DAC
http://www.head-fi.org/t/652116/am-i-crazy-he-500-sound-better-with-fiio-e9-than-02
There's this driving-your-headphones-so-loud-they-blow-out-your-eardrums fetish on head-fi, apparently, since in my experience on 1x (unity) gain the O2 gets my He-500s loud enough at about 2/3 volume to destroy my eardrums in 5 seconds. I'm guessing this guy's DAC isn't powerful enough, or I've listened to too many live events to believe music is ever produced that loud except at rock concerts. It doesn't need to be THAT powerful.

The ODAC, is in short, one of the most compatible sound cards I've ever plugged into a computer. It's simple and straightforward, a 24 bit/96Khz DAC chip that operates mostly noise free. There's really not much else to say, other than it sounds about as good as any DAC I've ever had. Other than when my old laptop chokes decoding FLAC off my encrypted external drive, it never skips at all. I've never heard noise off any of my laptop's USB ports, although some have reported it on laptops with shared-power USB.
It's becoming pretty clear to me that the more I read audio forum threads and the more I listen to different high end headphones, that these guys have the best of intentions and then proceed to deceive themselves.

Conclusions

I believe that Tyler and Mayflower deserve a warm recommendation from me. If you'd like a desktop-only O2, he should be at the top of your list. Just get your Allen wrench set handy, and don't expect the front panel printing to be exactly straight. This AMP/DAC combo cost me exactly $352.96 (The metal volume knob and the ODAC outputs were extra). It's not quite as cheap as the normal version, but I think the larger Jack will last quite a bit longer than the standard version. Also the black finish is far superior to the original brushed aluminum finish.
I think you'll be seeing this amp in meet pictures on head-fi for many years to come, even if (

) the people around them pretend it isn't even there. This isn't the greatest amplifier of all time; it's just the most standard amplifier of all time, through which any headphone can be judged for what it is without having to worry if the amplifier is making it sound different. I find that refreshing.

[Mysticode]

So this is all to listen to lossless music in the best quality possible? Seems like bit of an overkill to me, but that's just my view on it. It's chasing unicorns.

[h264]

So this is all to listen to lossless music in the best quality possible? Seems like bit of an overkill to me, but that's just my view on it. It's chasing unicorns.

But the unicorns are so pretty!

OK, I get it. Buying 5 sets of headphones and $300+ amps is not healthy. I figured that out a while ago, which is what I hope to impress upon the people who come on the audio forum wanting to drop $200 on the latest geez-whiz soundcard. It really doesn't help sound quality. You might like to HAVE some of the features on a higher end card. It might be a cheap way to drive your grandpa's old Koss headphones. But it will not make the unicorns smile or the pixies seem more golden.

However, a nice pair of headphones and an amp like this, especially for music lovers, DOES indeed make a difference. It's audible AND measurable. It's not 100000% better, mind you. I really enjoy listening to music without random noise and the driver issues I've had with other products.

If $300 is overkill, you should go see what people pay for mostly the same thing on Head-Fi. And the cables to connect them. And the fancy usb cords.

[Mysticode]

So this is all to listen to lossless music in the best quality possible? Seems like bit of an overkill to me, but that's just my view on it. It's chasing unicorns.

Heh no prob, I can respect your audio hobby, and I am aware of the crazy audiophiles out there, hell I'm friends with some people with $1000+ headphone set.

[h264]

So this is all to listen to lossless music in the best quality possible? Seems like bit of an overkill to me, but that's just my view on it. It's chasing unicorns.

>$1000+ headphone set

Heh, that's basically what I have between the O2/ODAC combo and the Hifiman He-500. I should probably review the He-500 when I get a chance, just to complete things.

[t0wer]

If this would have been out when I got in audio, I would have built one in a heartbeat.

[MayflowerElectronics]

h264,

I greatly appreciate the review you have done for me. It helps a small business like myself make itself known to others.

I'm going to address a few things from your review -

Packaging - I've noticed a few customers complain of the packaging not being rock solid, so we stepped up our packaging and now everything is rock solid, it won't move around which will get to my next point.

Volume knob - I do normally tighten down the volume knob pretty well, I am actually surprised it came off, something probably happened in shipping.

Face plate issues - I finally got confirmation of more panels being sent to me that are now fixed for future amps. If you would like to get a replacement, please email me and I will get one sent to you as soon as I get the new panels - (mayflowerelectronics@gmail.com).

Thanks again for the review!

-Tyler

[h264]

h264,

I greatly appreciate the review you have done for me. It helps a small business like myself make itself known to others.

I'm going to address a few things from your review -

Packaging - I've noticed a few customers complain of the packaging not being rock solid, so we stepped up our packaging and now everything is rock solid, it won't move around which will get to my next point.

Volume knob - I do normally tighten down the volume knob pretty well, I am actually surprised it came off, something probably happened in shipping.

Face plate issues - I finally got confirmation of more panels being sent to me that are now fixed for future amps. If you would like to get a replacement, please email me and I will get one sent to you as soon as I get the new panels - (mayflowerelectronics@gmail.com).

Thanks again for the review!

-Tyler

Oh yeah, I forgot to tell you I posted this. Been busy too. Glad you found it.

I'll send you a request for that new faceplate.

[misslily]

So this is all to listen to lossless music in the best quality possible? Seems like bit of an overkill to me, but that's just my view on it. It's chasing unicorns.

cool

[misslily]

like

[h264]

UPDATE: I got the new faceplate. This is a major improvement. His supplier seems to have gone back the brushed aluminum finish, but it doesn't stain like the old one.

[uncola]

Great review! Only one I've seen of a desktop version of the o2

[Eric1024]

Nice review :] +1

[Rhizo]

Nice review, and what people are saying about gear, its all about diminishable returns. As the price goes up, the improvement per dollar decreses.

[ShearMe]

Nice review, and what people are saying about gear, its all about diminishable returns. As the price goes up, the improvement per dollar decreses.

 

The price goes up because of small or non existent manufacturing runs and snake oil.

[Hyydrah]

Nice review. I'm not sure why it's so thick compared to this, though. They seem to be of the same sound quality

[h264]

Nice review. I'm not sure why it's so thick compared to this, though. They seem to be of the same sound quality.

 

you need the extra room for that 1/4" jack.  It's a standard variant that NwavGuy defined with the O2's original articles.