DACs are used by virtually all modern audio systems, so what are they and what do you need to know? DACs are available built into another piece of equipment or as a stand-alone unit. Moreover, prices range from £99 to over £16,000. The main difference is build quality and pedigree. Some companies have a long history in the digital market while others are more recent.
A key issue is the separation of functionality. Stand-alone DACs are likely to sound better, due to there being less interference nearby. For example a power amplifier with its high current wiring and large power supply. Having the DAC built into the same case is convenient but results in a compromise.
What is a DAC?
Basically DACs convert digital audio signals back into analogue. Once master recordings were made and stored on tape, as analogue signals. Nowadays multiple tracks are recorded onto a hard drive, as digital one’s and Zero’s. Software such as Pro Tools is used in the studio to manage the recording. There are a plethora of digital audio formats, sampling rates and bit depths in use. The DAC needs to be able to decode all of them. There is also the question of compression. Raw data files are large and take up a large amount of drive space. For example a CD holds about 700Mb of data, for 74 minutes of music. While the same space can hold over one hundred tracks in MP3 format.
Why is one DAC better than another?
Most devices, such as Smartphones and tablets have a built-in DAC, however this is often not optimised for music. The biggest issue is the clock timing. The data-stream needs to have a consistent signal. Timing errors are known as jitter and can make the sound muddy and uninvolving. Internal DACs are not optimised to handle these errors while external ones often have their own much more stable clock signal. Below we look all the types of DAC that are available. The easiest upgrade path for a Laptop or PC is an external headphone amplifier and DAC.
Headphone DACSs
A good example of a USB headphone amplifier and DAC is the iFi Audio GO Link Headphone Amplifier & DAC. This is a small USB powered device that can decode hi-res audio from your PC or laptop. The sound of the iFi Go Link is far Superior to the built in DACs usually found in PCs. The unit has a 3.5mm audio output for headphones or it can be connected to an amplifier. The DAC chip is made by the renowned ESS and the interconnecting cable is silver plated. Moreover an adapter can be used for your Smartphone. The next best way to purchase a DAC is as part of an integrated amplifier. There are all-in-one amplifiers that also have a built in streamer while others just have the DAC and an amplifier.
Integrated amplifiers
A top-performing but reasonably priced integrated amplifier is the Emotiva BasX TA1 Integrated Amplifier and DAC. This is a good bridge unit for analogue fans, as it has a built in phono preamp and FM tuner. There are digital inputs that can be used to receive the digital signal from a CD player, directly to the DAC. There is also a USB input to play locally stored files. Moreover, Bluetooth is also built in so you can stream from Your Smartphone, with services such as Spotify. A step-up from an integrated unit is a DAC/ preamp.
DAC preamps
Next we look at a DAC preamp, with the high end Pro-Ject Pre Box RS2 Digital Pre Amplifier / DAC / Headphone Amplifier. This type of unit is designed to be paired with a high quality external power amplifier. It features a dual mono design along with two separate DAC circuits for the best possible channel separation. Moreover ESS Sabre. ESS9038Q2M chips are used that provide the highest sound quality. As with best units, balanced inputs and outputs are provided, as well as RCA inputs and outputs. This unit is designed to be used with a separate streamer front end. However DAC/streamer/preamps are also available. These are sometimes also known as network players.
DAC streamer preamps
DAC streamer preamps also known as network players include everything you need except for a power amplifier. The TEAC NT-505-X USB DAC and Network Player Streamer is a good mid priced example. This unit features an ES9038 Q2M high-performance DAC along with 7 types of PCM filters, these can be used to tailor the sound to your liking. Moreover the cabinet features a Stressless Foot” design with three support points. This ensures there can be no external interference.
Streaming features
The Teac NT-505 has a wide range of streaming features. It can be used with TEAC’s own app to control your playlists. Moreover it can also be used with Roon. All the usual streaming services are available including TIDAL and Qobuz. These services provide lossless audio files. Lastly, you can stream off your network via a wired Ethernet connection or use Bluetooth. Lastly we look at the ultimate in DACs, with a stand alone unit.
Stand-alone DACs, £99 -£16,000
The best sound quality can be obtained with a separte DAC. Some even have analogue valve output stages so that you can have the best of both worlds. one such device is the Synthesis Roma 69DC DAC. This unit costs around £2000 but is a no-compromise design using the best possible components. The unit has two optical inputs as well as two coaxial inputs. additionally a USB socket can be used to connect external hard drives. The valve output stage provides a warm and musical sound that other DACs cannot match.
To sum up, the best sound can be obtained with a stand alone DAC, however even a simple external DAC will vastly improve the sound of a PC or Smartphone. The complexity of the system increases as you separate the functionality, so contact Audio Affair for advise.