Elite list: the best DACs for audio

As detailed in our exhaustive piece about testing headsets and headphones, audio is serious business. But, let's throw the term audiophile out the window. It means different things to different people. The bottom line is, audio is as important in games as it is for those who just listen for the pure enjoyment of music.

Sound cards largely fell by the way side in the last decade as motherboard companies integrated better and better sound solutions. These days, you can find pretty decent DACs on a motherboard. But, what is a DAC?

Simply put, a DAC or digital-to-analog converter, does the job of changing the digital information in your music files into an analog signal to be sent to your speakers for amplification. Every device that can read a digital audio format, like an MP3 file, FLAC file, or CD, has a DAC. Yes, sound cards are essentially DACs on a board. The arguing point in the last decade or so has been, do DACs improve audio over onboard sound? Short answer: Yes they do.

Measuring equipment:

The best headphones A great DAC is only useful if you have a great pair of high-end headphones plugged into it. After testing dozens of pairs, we put together our list of the best headphones.

Onboard (BLUE) vs. DAC pre-out (GREEN), volume min



Onboard headphone out (PURPLE) vs. DAC headphone out (RED), volume min

Onboard out (BLUE) vs. Onboard headphone out (PURPLE), volume min

The audio output from the HA-1 is outstanding, naturally. It's clean, free of noise, and the frequency response is excellent. Compared to onboard, noise and distortion is significantly less. Keep in mind that the dB scale is logarithmic, meaning for every 3dB the perceived volume doubles. It's safe to say from measurements that going external is significantly better.

After a month of testing several DACs, we selected four we feel are the best DACs if you're considering using headphones or speakers, or both. For reference, we chose MrSpeakers' Ether headphones to test all 3 DACs.

The best DAC/headphone amp for headphones

Woo Audio WA7d Fireflies

The Woo Audio WA7d Fireless is unlike any DAC/headphone amp we've ever seen, primarily because it doesn't look like anything else in its space. It's made to be presented. The base is solid aluminum and the crystal clear glass block crowns the overall unit, protecting the two tubes while also looking sexy. Overall, it's the best attainable elite-level DAC/headphone amp and one we use on a regular basis.

On the rear, you have all necessary inputs for piping in signals: RCA inputs, optical, and USB. You can use the WA7d as a standalone headphone amplifier with any audio playback device, but it shines connected to a PC. Plug in the USB cable and you're ready for pure magic. A switch on the rear dictates the source you want to use.

The WA7d Fireflies is a class-A tube headphone amplifier that boasts exceptionally good audio output and support of formats up to 32-bit/192kHz rates. It won't decode DSD files, but it's okay, there's just not enough DSD content anyway.

At $1,199, the WA7d commands a premium, but that's to be expected for the caliber of audio it's able to deliver. You're getting sound that would otherwise typically be reserved for products costing twice as much. Woo Audio knows this, and it shows because the company has taken some of the best features from its other higher-end products, and distilled them down into a package the size of four hard drives. Woo Audio's other products can ramp up to well over $10,000, and its products are often used by top headphone companies to demonstrate performance.

Specs:

Single-ended, class-A, transformers output

Linear external high-performance power supply (remote-controlled power switching)

Two 6C45 driver/power tubes

C-Media 6631A USB chip

TI PCM5102A 32-bit DAC chip

Headphones impedance : up to 600 Ohms

Sampling rate: up to 32-Bit, 192kHz

Inputs: 1 Optical, 1 Asynchronous USB2.0, 2 RCA, 1 USB DAC

Outputs: 1 1/4" and 1 1/8" headphone outputs

Max output: approx 1 watt @ 32 ohms

Frequency response: 11Hz to 27kHz, +/-0.5dB

Distortion:

S/N: 95dB

Power consumption: 25W max

There are three factors responsible for the WA7d's excellent audio performance. The first is its class-A power delivery. Class-A amps aren't efficient, and run hot, but they are pure analog amps and sound the most truthful to the original music. Lesser amps will choose to go with other classes which, while electrically more efficient, don't perform as well musically. Even so, the WA7d only gets very mildly warm. It also helps that its high-quality linear power supply sits externally.

Secondly, its TI PCM5102A DAC chip outputs a very balanced sound, and is favored by many DACs in this class, and even higher end options. Sampling rate goes up to 192kHz, and resolution is at 32-bits, which is more than every high-resolution recording currently available. Unfortunately, going above 24-bits means the WA7d will require drivers on Windows machines. OS X users do not require drivers.

Thirdly, it's well known in the audio community that tube amps create a silky, warm tone to music, but the WA7d doesn't color your audio in a way that makes it inaccurate. In fact, quite the opposite is true. Woo Audio designed the WA7d in such a way that maintains neutrality, while adding just enough warmth to its output. The result is audio that sounds organic, alive, and smooth. The drawback? Tubes have a limited life-span. The uptake? You can "roll" your own tubes. If you don't like the way one set sounds, you can swap out for a different set up tubes to tune the sound to your own liking. However, we reckon that almost everyone will prefer Woo Audio's pick, as we found its setup to be the most balanced.

If you're looking to use headphones most of the time, or exclusively, the Woo Audio WA7d Fireflies is our top pick.

The best DAC for connecting everything

Oppo HA-1

For $1,199, the Oppo HA-1 has one of the most sought-after features for a DAC: an ESS 9018 Sabre 32 DAC (PDF). This DAC can be found in some of the highest-end home theater receivers. The ESS 9018 DAC is widely considered as the best audio DAC in the world (many consider the Analog Devices DAC in the Schiit Yggdrasil to be the actual true king), but ESS recently announced a new flagship DAC, the 9038PRO. Both DACs support 32-bit/384kHz on all channels. The 9038PRO has an incredible DNR (dynamic range) of 140dB (129dB for the 9018) and THD+ (total harmonic distortion plus noise) rating of -122dB (-120dB for the 9018). The entire audio path from power delivery to signal conversion is equally important in supporting a good DAC. You can find small USB adapters that have the Sabre DAC for less than $70, but the audio output won't be great.

If the ESS 9018 Sabre is the heart of the HA-1, then the class-A amplifier would be its soul. Similar to the Woo Audio WA7d, the sound delivered by the HA-1 is extremely clean, with a very low noise floor. Even with the volume cranked to maximum, our headphones delivered nothing but silence.

If you're interested in running a USB DAC, take note that the HA-1 is an asynchronous USB DAC (like the Woo Audio WA7d), meaning it doesn't rely on the host computer's USB clock generator. If you're already familiar with USB DACs, sound output can be affected by poor USB clocks on the motherboard. DAC dropouts and/or strange noises when switching sampling rates are common. If you have a USB DAC and are experiencing issues, you might consider Schiit's Wyrd USB Decrapifier, which cleans up and rechecks the USB signal, virtually eliminating any problems you may have with your DAC, unless the DAC itself is going bad. We have two Decrapifiers, and they work.

Specs:

Discrete class-A amplification

ESS Sabre32 Reference ES9018 DAC

Fully balanced configuration

Headphones impedance : up to 600 Ohms

Sampling rate: up to 32-Bit, 384kHz

Inputs: 1 Optical, 1 Coaxial Digital, 1 AES/EBU digital, 1 Asynchronous USB2.0, 2 RCA, 2 Balanced-XLR, Bluetooth 2.1+EDR (with aptX), 1 front USB, 1 rear USB DAC

Outputs: 2 RCA, 1 1/4" and 1 Balanced-XLR (headphone), 2 Balanced-XLR speakers

Max output: approx 3 watt @ 32 ohms

Frequency response: 10Hz to 170kHz, +/-0.3dB

Distortion:

S/N: 115dB

Power consumption: 75W max

Special formats: DSD (DoP v1.1 or native) decoding, on screen display, remote control

Besides being a fantastic headphone amplifier, the HA-1 is also great as a pre-amp for speakers. We like the HA-1 in particular for having both single-ended and balanced XLR outputs. Most speakers will connect to the single-ended RCA jacks, but if you're planning to use professional studio monitors, like the ones we chose, the balanced outputs will help reduce noise significantly over longer cable runs.

How does XLR balanced connections work? Using a technique called differential mode, the audio signal is carried over two separate wires with opposing polarity. The two signals are summed together at the receiving end (which must be differential-capable). ANy noise or interference is cancelled out, and what you're left with is just the clean audio signal. With the noise signal removed, what you're left with is a clean audio signal. We made sure our entire signal path is fully balanced, with the same XLR cables through all interconnects, to ensure that the impedances are matched. If you're using headphones with the HA-1, it has support for both normal and high-gain output, and supports both headphones using 1/4-inch TRS connectors as well as balanced XLR connectors.

Aside from XLR, the HA-1 essentially supports every available input format: AES/EBU digital, coaxial digital, optical, USB DAC mode, RCA, Bluetooth, and a front USB port for connecting iOS devices, such as an iPod.

Oppo also filled the HA-1 with plenty of other useful features. Audio over Bluetooth in the form of aptX support is included, as well as a pure analog potentiometer for volume control. Many other DACs use a digital volume control chip to control output, which adds an additional step in the audio path. The HA-1 maintains a completely analog path from DAC to connector.

One minor complaint we have with the HA-1 is its inability to mute the pre-outs directly on the unit itself. You must use the supplied remote control to mute your speaker output if you decide to switch over to headphones. This is annoying and we hope Oppo can include it in a firmware update. If you lose your remote, you'll be unable to mute speaker output.

The Oppo HA-1 is our pick if you want to support multiple inputs, say from 2 computers, a phone, and a SACD player. You're guaranteed flexibility and switching between inputs is as easy as turning a knob.

The best discrete DAC

Schiit Gungnir multi-bit

For those looking for the best discrete DAC—that is, a DAC without a built in amplifier—our best pick is the Gungnir multi-bit from Schiit. Yes, that's really the company name. And no, it's not a fancy German word for audio.

We'll save you the history behind the company and its name. If you want to read about how it all started, check out this long story from Schiit co-founder Jason Stoddard on Head-Fi.org. The bottom line is, Schiit's products are revered in the audio community. At headphone conventions like CanJam, Schiit's DACs and amps are often used as the standard demo platforms for headphones.

Specs:

4 Analog Devices AD5781BRUZ

Fully balanced configuration

Sampling rate: up to 24-Bit, 192kHz

C-Media 6631A USB chip

Inputs: 1 BNC, 1 Coaxial Digital, 1 Optical Digital, 1 Asynchronous USB2.0,

Outputs: 2 Balanced-XLR, 4 RCA

Max output: 4V RMS (Balanced), 2V RMS(RCA)

Frequency response: 1Hz to 200kHz, -1dB

Distortion:

S/N: 115dB

Power consumption: 20W max

Special features: multibit (ladder) DAC, upgradeable USB input, DAC/Analog cards, bitperfect Adapticlock analysis and VCXO/VCO regeneration

The Gungnir multi-bit is different from nearly almost every other commercial DAC in that it employs a multi-bit ladder DAC configuration as opposed to traditional delta-sigma DACs (used both in the Oppo HA-1 and Woo Audio WA7d). Delta-sigma DACs have the ability to ramp up in resolution and sampling rate, but actually aren't accurate in the sense that the original audio samples are discarded. Essentially, delta-sigma DACs mathematically choose a sample based on algorithms that best represent the original sample. Ladder or multi-bit DACs do the opposite, they keep the original samples. The Gungnir multi-bit then, is accurate. What you play, is what you get.

For $1,249, the Gungnir isn't your cheapest high quality DAC, but it is one of the best for the money, in terms of what you're getting. Without going into details that can turn into a full essay, Schiit has stuffed the Gungnir multi-bit with some of the best components on the market, and designed it with analog performance in mind.

Design wise, the Gungnir is a pretty large standalone DAC. It's about the size of a very large shoe-box, and about one-third the height. It doesn't have any fancy knobs or flashing lights. One button on the front changes inputs, and a small hard lever on the rear turns the unit on. Its chassis is as tough as nails though, and the unit sports clean simple lines all around. It's slightly big to sit neatly on a work desk, but hey, if you want the best you have to compromise sometimes— such as eating ramen for a month to save up for gear.

On the reverse side, Schiit included several methods of input: USB, coaxial digital, optical digital, and BNC. Obviously there's no analog inputs because the Gungnir is a DAC only. For outputs, you're given two stereo pair RCAs, and a set of L/R balanced-XLR outputs. If you're buying the Gungnir, it means you know exactly the type of amp you want. For those who are curious, yes, you can use the Gungnir with powered monitors or speakers. You can think of the Gungnir as a godly external sound card.

In terms of sound, the Gungnir is the best we've listened to. It doesn't have the mathematical sound of a delta-sigma DAC and when paired with a tube amplifier, like Schiit's own Mjolnir 2, the sound is glorious. Smooth. Clean and devoid of noise, faithful, and present. You'll have to do a direct comparison to hear the difference, which is what we've been doing with the above 3 DACs for over 2 months.

Ideally, you'll want to pair the Gungnir right along with Schiit's Mjolnir 2, which is a hybrid-tube or fully solid state amplifier if you're going to go headphone-serious. This would place the whole Schiit stack to $2,098, nearly $800 more than both the Oppo HA-1 and Woo Audio WA7d. But at this price, you're on another level altogether in terms of serious headphone use. It's very likely you're also in the market for an end-game headphone as well.

If you want an absolutely fantastic discrete amp that you can pair with a discrete amp of your choosing, the Schiit Gungnir multi-bit is our pick.