JDS Labs OL DAC - Reviews
Pros: Great Price/Performance Ratio, Compact Form-Factor, Clean&Black Background, Great Control & PRaT, JDS Support.

+ Great synergy with HD6XX!
Cons: Bulky adapter.



Many of you already have an acquaintance with JDS Labs because of their widely popular O2 and CMOY amps. I’ll look at the new OL DAC and O2 stack today! Interview with JDS is also available to read at www.QuantumEars.com


  • AK4490EQ DAC
  • USB Type B and TOSLINK Input
  • RCA Output
  • Case Dimensions: 11 x 8 x 3 cm
  • Weight: 370 grams
“O2 Amplifier”
  • RCA Input
  • 3.5mm Output
  • Max Output @33 Ohms: 613 mW
  • Max Output @150 Ohms: 355 mW
  • Max Output @600 Ohms: 88 mW
  • Dimensions: 11 x 8 x 3 cm
  • Weight: 310 grams
Build Quality, Packaging
Designed, sourced and manufactured in USA. Packaging is quite straightforward, the stack comes in a static bag inside a cardboard box. Like the packaging, the design itself is simple and practical. JDS aimed for one thing. Efficiency. Both of the devices have excellent thermal capabilities so they run cool and occupies little to no space. Switches and plugs feel solid, well made. One thing I can’t seem to wrap my around is why RCA plugs are not aligned? I can’t use my ultrashort RCA interconnect with them because of this. It’s not a big deal though, I am sure if you leave a note they’d adjust plugs accordingly.

OL DAC offers a rare feature for a relatively affordable price tag. Optical input! Good news folks! We will not be enslaved by petty USBs anymore., I always prefer Optical because with my high-end desktop computer USB audio is tricky, USB ports are not as clean as I’d like, fortunately my motherboard offers an optical out so I pair it with OL DAC without any jitter/noise issues.
Oh by the way, OL DAC is driverless! Just plug it in & you’re ready to go!


Customer Service
Unfortunately I ran into several problems with the shipping & customs. They flagged the shipment “volatile/flammable” and in result this delayed the review quite a long time.. In every step, JDS was understanding, patient and solution-oriented. Thanks again Jude!

Sound Signature
Transparent. This is perhaps only label that we could put on the JDS Stack. Both OL DAC & O2 sounds raw. Clean. Clear. If you’re looking for pure performance, you’re in the right place. If you’re looking for fun signature, look elsewhere. Converting the signal from digital to analog, nothing more. No colouration, no particular band elevation, no emphasize, nothing. Pair it with a studio monitor and you’ll have the perfect mix/master combo.

Low Frequencies
Low frequencies are tight and snappy. “JDS Stack” does not overdo the low section, you hear exactly what is in the recording. Entire bass freq line is flat. This results in accurate reproduction but it is not as musical as, say, something like Centrance Dacport. The bass detail level and attack/decay is impressive as well.

Mid Frequencies
When we look at the mid region, it is easy to see that they are similar to rest of the spectrum. They’re accurate, articulate and linear. Tonal balance is impressive. No out-of-place elements in the presentation. Lower mids are perfectly balanced, there is no sign of any humps. Upper mids are similar as well, they’re not boosted therefore no sign of harshness. Cymbal & Hi-hats are crisp and well controlled.

High Frequencies
Treble has excellent control just like the rest of the spectrum and I did not encounter with congestion of any kind. (I even tortured it with Blind Guardian - Mirror Mirror)
Detail-wise it is ahead of many and it offers great value for price.
Treble extension and attack/decay is really impressive.

Instrument Separation, PRaT, Soundstage
Soundstage is wide, rather than deep. Instrument separation is good, instruments have plenty air and space between them. Presentation does not suffer from PRAT issues, which is quite amazing at this price because many do. JDS Stack’s background is vantablack.


They’re in the same pool but there are some distinguishing factors between them. Modi&Magni’s soundstage encircles you, JDS stack does not. JDS Stack have more distinctive soundstage area. Blacker background. Detail wise JDS is 1 step ahead. I find JDS tad better in the control area, especially during complicated metal passages.

Audioquest Dragonfly Red
Red sounds tad lighter, little more emphasis on the treble section. Similar soundstage. JDS stack is much more powerful. JDS stack offers much better PRAT and handles congestion without any “screeching”. Also compared to DF Black, JDS combo sounds relaxed and spacious.

O2 vs H10 (both with oldac)
H10 adds warmth to the sound, low frequencies get slight boost and authority, treble takes a step back compared to O2. Both are great, detail-wise but with good recordings H10 is more revealing. H10’s soundstage is deep rather than wide.

Final Words
When you add the performance, features and JDS support into the equation, OL DAC & O2 combo is a no-brainer. You can even customize them to your liking. Even the gain. Today, the JDS stack is inseparable from my desktop rig. It really doesn’t matter whether I am gaming or listening. I know that I am in good hands.


Thanks for reading.
Pros: Good, clear, noise-free sound, AK4490EQ DAC, plug & play, flawless build, decent heat management, price, brand reliability
Cons: Expandability options lag behind the competition
For enjoying my tunes better, should I buy an integrated DAC/amp, or a DAC and an amp separately? What should be the first step?
I come across these questions very often among music listeners.
About DACs and amps, I can't say that I am a fan of all-in-one designs. When you wish to upgrade your DAC or throw in a beefier sounding amp, integrated solutions decrease flexibilty.
Swapping DACs, amps, preamps is much more easier in separate designs.


For that, I’ve always been a fan of modular designs through which a music enthusiast can experience & taste & experiment on different combinations.
Choosing a DAC, adding an amp, a preamp, headphones, rolling op-amps and tubes accordingly with one’s own tastes all form the path to creating “the ultimate setup” that pleases a music lover most.

That highly enjoyable “journey” might vary for each of us ; but a good, dependable and hiss-free DAC is a nice place to start.

A couple of months ago, as a past time admirer of the good-old ODAC, I bumped into the new DAC design by JDS Labs while searching the web. And compared to ODAC, the word “upgrade” in the description of the new OL DAC grabbed my attention.


Mr. Seaber and Mr. Hopper from JDS Labs, generously offered me to review OL DAC with full confidence on their product, in exchange of my honest opinion.
And here are my impressions of this little DAC.

At first, I should state that OL DAC is tiny in its aluminium housing.
Photos of this DAC in the web do not do justice, it is that small with virtually negligible footprint.
Let’s say, if you’re short on space in your desk, then you should benefit highly from the size(lessness) of OL DAC.
Yet interestingly, even with pull of the various cable attached at the back, it is quite hard to move it, thanks to the very nicely added silicone feet at the bottom.
Well thought.


At the back, OL DAC has two gold-plated RCA outputs, an optical input (to plug OL DAC to various home entertainment devices), a USB Type-B socket, and a socket for its 15V AC adapter.
However, it lacks coaxial input, which is present on most of the competing products like Schiit Modi Uber 2 or Topping D30. (Coaxial input is available in the pricier EL DAC)

I should say the adapter may look a little bit big compared to the tiny size of the device. A tiny little big, but nothing extraordinary.


For the external design, OL DAC reminded me of a fully function-oriented product from Soviet industrial art with little emphasis on the “cosmetic appearance” of the outer look. (Much like it’s sister design Objective 2 amp)
And for those who are old enough to know the famous durability of old Soviet products, OL DAC really seems to be made to last.

One thing not often taken into consideration about these devices by reviewers (and that I strictly pay attention in DACs and other electronic equipments in general sense) is their thermal design.
Proper heat dissipation can sometimes be a must in electronic devices for stable operation and also durability in the long run.
On that matter, OL DAC passes the test easily.

I am writing these lines right now in Istanbul, in a classical hot Turkish summer weather with an average of 28 to 30°C (something like 85°F) room temparature.
In that condition, OL DAC gets slightly warm during use, but never ‘hot’ unlike what I’ve observed in some other DACs.
This would positively contribute to the longevity of the product for sure.
I can’t say that I succeeded on finding a flaw on the build department.
Well played.


I gave several listens to OL DAC intermittently in various setups over a period longer than a month.

For comparison, I tried to find the popular Topping D30 and SMSL M8 DAC’s, in order to get a more coherent picture about the performance of OL DAC at it’s price of $139.
I succeeded in accessing the latter, so in the following part of the review, I’ll state my impressions about OL DAC and SMSL M8.

In my reviews, I usually try products through different setups and combinations to reach an overall estimation of their average performance.
I did the same for OL DAC, matching it with an O2 amp, connecting it to my Yamaha HS7 reference monitors, and using it as a sound card with my PC through Logitech home theater speakers in 2 channels mode.

With O2 amp, I used the duo to power some low impedance Sony headphones (MDR1-ABT, 1000x) and Grado PS500e as well as an 300 ohm Sennheiser HD650.

The sound with this stack is strikingly clean with virtually zero grain as well carrying a balanced presentation across the frequency range.
Yamaha HS7's helped to show the strengths of OL DAC better, as they are designed to reveal the characteristics of the source material / devices.
Even through HS7's, which show any coloration, warmth or brightness of the source quite easily, I found OL DAC to be very neutral with a tiny bit of warmth that prevents me from describing it as "cold / clinical sounding".
Compared to the sound card in my computer (with Realtek ALC887 sound chip) I observed some differences even through my Logitech speakers which are not one of the most revealing speaker sets as one may expect.

Through that setup, I found the Realtek chip to sound definitely more coloured and "fun" sounding with some dips and elevations in the frequency and to sound more processed / veiled with inferior resolution.
The difference is not day and night as you may expect, however, OL DAC's superiority in measured performance easily shows itself to trained ears.

Finally, the comparison with SMSL M8 was a mixed bag.


Through pairing each of these DACs with O2 to power the headphones I mentioned above, I found a very small difference in sound, while in "sound card mode" with Logitech speakers, I've heard no difference in overall sound aside from the very slightly sharper treble on SMSL M8.

Over Yamaha HS7's, the difference between OL DAC and SMSL M8 became a tad bit more percievable though still being very small.
Through that setup, SMSL M8 sounded even more clear than the already very clear sounding OL DAC with slightly more transparency and air & sparkle in the treble region while OL DAC presented a slightly smoother sound.
However, this "difference" of SMSL comes with two potential problems, first being a slight "digital feeling" in sound, and latter being the diminished matchability with brighter headphones.

Besides, SMSL M8 became almost too hot during operation as well as having slightly inferior build quality compared to OL DAC.
However, I should state that the one I used for test was the standard / old M8 version, not the newest update M8A. This overheating issue might have been solved with the newer one.

OL DAC : So who is it for?

Let me say it first :
OL DAC is not for people looking for the extreme levels of "clinical" detail that are buried deep in the recordings (DACs costing +$1000 can do attain that actually - and not all of them).

OL DAC is not for people who want to do native DSD.
As a USB Audio Class 1 device, it supports up to 24/96kHz over USB, and 24/192Hz over optical input.
OL DAC presents a "best bang for the buck" sound and features for those who do not need fancy features or support for formats (like native DSD) of more expensive DAC's in the market.

It produces a very clean, flat, dynamic sound with an excellent noise floor (as a DAC should do) and decent soundstaging. And with OL DAC, one could get a great deal of the sound of much pricier DAC's in a very compact package and at a fraction of their costs.
My observation is that for each dollar spent after $150 you would get increasingly smaller increments in sound department.
(Besides, one can check the "B-Stock sales" in the JDS Labs site. From there it is possible to get an OL DAC with minor cosmetic imperfections over an even better $124 price.)

For people, who seek budget-friendly audiophile solutions, or ones that do not want to mess with fancy formats etc. OL DAC is a very good and mature DAC.

As I've stated in the header, OL DAC seems to be "A Perfect Start For The Minimalist Audiophile".
Pros: Price-to-performance, transparency, simplicity
Cons: Neutral tonality may not suit all listeners
I know a lot of people say a DAC is a DAC is a DAC, but I’m not one of them. A DAC’s chipset and its implementation, among other things, play a very real role in determining how it sounds. Well, the OL DAC doesn’t really sound like anything, and I don’t mean that in a bad way. Quite the contrary. The OL DAC is audibly transparent, which makes it a great reviewer’s tool. But what about for the rest of you? 

Satisfactorily small and straightforward, the OL DAC was, as JDS Labs’ Jude Hopper  and John Seaber tell me, “an accidental child.”

As the company was experimenting with single-unit prototype DAC/amp combinations based on the open source amp design philosophy of acclaimed audio blogger NwAvGuy, it became apparent that the best bench tests came by way of standalone self-powered units. A standalone DAC design also allowed JDS Labs to better implement its USB and Optical inputs—a move aimed at appeasing customer demand for support for games consoles, CD/DVD players and other devices. And, so, the OL DAC was brought to market. 

But let’s be honest, it’s not an “exciting” product—it’s just an affordable DAC ($139) that does its DAC duties well. And that’s why people love it. The roughly 4”x3”x1” box provides nothing but the basics. On the backside there’s one plug-and-play USB Audio Class 1 input (16/44.1 thru 24/96), one Optical input (16/44.1 thru 24/192), one gold-plated RCA 2.0V output, and a jack for the 15VAC linear power supply. On the minimalist front there’s a power button, USB/Optical slider switch and single green LED. Inside you get the premium AKM AK4490EQ DAC chip—which also appears in high-end audio components from the likes of Astel&Kern, ESOTERIC, Marantz and others—that’s summed by an ultra-low noise and wide bandwidth Texas Instruments OPA2227 operational amplifier. Done. 

As I mentioned, one of the things I appreciate about the OL DAC is that it’s very transparent—there’s no coloration, or hints of overemphasis in any specific area of the dynamic range. Mating it to my O2, Eddie Current Balancing Act or HiFiMan EF-6 allows the traits of each to become readily apparent, not to mention what my head gear or speakers are doing. For tube audio fans, eliminating the influences of an audibly colored DAC allows for more immersive and effective tube rolling. Add in the fact that the OL DAC has an absolute noiseless, pitch-black background and nice detail retrieval, and that whole search for system synergy gets a little bit easier. 

The downside here, if you can call it that, is that transparent can be “boring”. It’s not what I would consider especially lush or organic (my preference); it’s just clean and clear and conveys a good sound stage. But the point is that you can marry this little low noise, low jitter, low distortion DAC to any amp you wish and end up with banging budget audiophile results (did I mention that the OL DAC is $139?). There are no surprises with the OL DAC, and that’s not a bad thing at all.
I own this DAC. The OL DAC is about as neutral as it gets. I have a Sabre ES9018 DAC at home, at it does seem to open up the top end a bit more with my higher-end cans. This DAC, paired with the O2, is just a pleasure to listen to. Music sounds as it should. I have listened to the Modi 2U and could not tell the difference between the OL and the Modi. I bought the OL because it sits in a nice stack with my custom JDS O2. I fell out of love with Schiit after ordering two products from them that came with faulty potentiometers. I decided to try another company -- one that tests their products prior to sending them to the customer. JDS Labs has exceeded my expectations, and this DAC is no frills, looks great, and is absolutely neutral. A WIN.
Glad you're enjoying OL DAC!
@SoundApprentice - The AK4490EQ can be configured to use other filters, if you're after something other than a neutral sound signature. Some of the filters impact high-freq response by more than 3dB IIRC. http://blog.jdslabs.com/?p=1381
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@jseaber Really cool tip on the filters!