“Hey, I was just wondering what the major differences were between the ODAC and the OL DAC.”
This fine question continues to pop up in emails, on the phone, on reddit, on Head-Fi, etc.
I was excited to push OL DAC into the wild last November for a number of reasons. I’ve always placed great trust in JDS Labs customers, finding them to be knowledgeable value hunters, and OL DAC set a new bar. Alas, we omitted too many details at release, like why we created another transparent DAC in the first place. Rumors took off. My favorite assumptions include:
ODAC and OL DAC are the same circuit in different boxes (False)
OL DAC costs less, so performance must be lower (False)
In short, the DACs share few similarities, aside from comparable transparency.
OL DAC clearly has the upper hand in terms of performance.:
+/- 0.04 dB
+/- 0.15 dB
< 0.0029 %
< 0.0010 %
Dynamic Range (A-Weighted)
> 112 dB
> 114 dB
Crosstalk @ 1kHz, -10dBFS (RCA)
Sum of Jitter Components @ 11025 Hz
IMD CCIF, -6.03 dBFS, 19/20kHz, 24/96k
IMD SMPTE -2VRMS, 24/96k
Linearity @ -90dBFS
+/- 0.01 dB
THD+N Sweep (24/96kHz, 20-20kHz)
Frequency Response (24/96kHz, 20-20kHz)
USB Jitter @ 11025Hz
Why Another Transparent DAC?
ODAC was interesting five years ago for its claim of transparency at only $149. DAC performance and features improve every year; OL DAC is the logical successor. While there’s no need for “greater transparency”, few can argue with getting more for less.
There remains one potential advantage to choose a Standalone ODAC–running from USB power can be useful in certain scenarios. Thus, we decided to maintain ODAC and OL DAC concurrently. Confusing? Yes, sorry about that.
There are three basic requirements to connect a USB DAC to any Android or iDevice:
Power: The DAC must not consume more power than the phone or tablet permits.
Support: The phone or tablet must be able to stream digital audio over USB.
Cables: You must use an appropriate cable for your device.
Below we’ll show how you can connect a USB DAC to most Androids, iPads, and iPhones.
All iPad, iPhone, and most Android devices enforce a peripheral power consumption limit. If you have a self-powered DAC like C5D, this requirement is easily satisfied since the DAC only consumes power from its own battery.
Connecting a more common, power hungry DAC is still possible! USB devices declare their power consumption in software, during USB enumeration (connection). Therefore, it’s easy to trick a phone or tablet by connecting the DAC to a small USB hub. With the right USB hub, your phone only reads the low power consumption of the USB hub, and not the larger power consumption of the DAC.
For example, directly connecting ODAC to an iPhone or iPad does not work. ODAC consumes about 20mA, while iPhone/iPad permits a maximum current consumption of around 5mA in software. With a portable USB hub connected, ODAC now works!
Power consumption has not actually changed here since we’re using a non-powered USB hub; ODAC still draws power from the iPhone.
A powered USB hub would be more ideal, but this experiment shows it’s possible to fool the software power limitations. Also note that a USB hub will only work with your phone or tablet if it reports itself as “self-powered”. Not all portable USB hubs report their power consumption this way. We’ve had success with Plugable’s USB 2.0 2-Port hub, but it’s worth mentioning that some customers have received Plugable hubs that do not work. Again, a powered hub is the best choice.
History Lesson: It’s safe to bypass the tiny power consumption limit of your iDevice. Maximum power consumption of iPad was much higher in iOS4 and earlier, so most standard DACs worked out of the box with iPad back then. Apple later reduced the software power limit causing standard DACs and other peripherals to only connect when used with a powered USB hub.
Android Devices – DAC Connections
Cables: Any USB On-the-Go (OTG) cable will suffice. Android devices use a micro USB port, while most DACs rely on mini USB. A micro-to-mini OTG cable makes a perfect connection.
Support: Digital audio support with Android continues to improve. While only some Android devices support digital audio out of the box, nearly all Androids can connect to a DAC using USB Audio Player Pro. And if you’re adventurous, Cyanogenmod is known to enable streaming digital audio systemwide (all apps) for most devices.
Tip:Even with the proper cable and support, Android sometimes needs a reboot. Make sure to turn your DAC on and connect it to your phone/tablet, then reboot Android. This will give Android a chance to initialize the DAC.
Apple unlocked digital audio support under iOS 7, so all iPhone and iPad devices painlessly connect to self-powered DACs. Support is excellent.
Unlike Android, Apple’s proprietary cables are the only point of confusion. There are presently four possible connections, and only three of four work.
Lightning to USB Cables
The best solution for now is Apple’s Lightning to USB Camera Adapter, part number (MD821ZM*)MD821AM. This cable conveniently provides a USB port from your iPhone/iPad, allowing you to connect a short mini-USB cable to your DAC.
One might expect that Apple’s Lightning to Micro USB adapter (MD820ZM) and a short USB cable would also work. We’ve confirmed this adapter is NOT usable with DACs! Apparently it was made only for charging.
*Update, October 19, 2015: We have successfully tested Apple MD821ZM with iPads and iPhones running iOS versions 7.XX through 9.0.2 (most recent version as of today). Apple has recently replaced MD821ZM with a newer version, MD821AM. DAC support of MD821AM has not yet been confirmed.
Apple 30-Pin to USB Cables
For iPhone and iPads with an older 30-pin dock connector, you’ll need Apple’s 30-pin Camera Connection Kit (CCK), Apple part number MC531ZM.
Note that iOS 7 is mandatory to use a DAC, meaning these adapters are suitable for iPad, iPhone, and iPod Touch running iOS 7. There’s currently no standard digital audio support for iPod Classic or iPod Nano, as they do not support iOS 7.
If you already have a 30-pin CCK and a Lightning-to-30-pin Adapter (MD823ZM), it’s possible to pair these two connectors together to form a bulky Lightning to USB adapter:
Addendum: You can use any mini USB cable with the above Apple accessories. The stock, 1.5ft cable provided with C5D will work, or you may choose a shorter cable. Some users also prefer to strap their devices together with silicon bands for better organization:
Generic Lightning Cables
Now you’re probably asking yourself, “Why doesn’t someone make a short Lightning to mini-USB cable?!”
It was a quick task for us to find a great manufacturer for our custom Android OTG cables. Sourcing the equivalent Lightning-to-mini-USB cable is vastly more challenging. Apple controls the accessory market under its MFi Program. JDS Labs has applied twice in the past 3 years and has yet to receive a go ahead. This leaves us with three options: We can either source generic Lightning cables from non-MFi certified manufacturers, or we can partner with an MFi approved developer, or we can continue to wait for our own MFi certification.
We’ve found several overseas vendors willing to product custom Lightning cables, but we have no interest in breaking Apple’s MFi agreement or distributing cables which may not always work. So, generic cables are not an option. We’ll continue seeking a path of MFi approved production.
Power – Use a self-powered DAC. For other DACs, you can use a self-powered USB hub.
Support – iOS7 fully supports streaming digital audio!
Cables – Use Apple Camera Connection Kit cable + mini USB cable