INTRODUCING THE LINK

A NEW ERA OF DIGITAL AUDIO

The Stack Audio LINK is a new USB music streamer. Here at Stack Audio we understand the importance of a clean audio source. Music sounds more real, enjoyable and immersive when we can remove unwanted noise, resonances and interference. These sources of extra energy are simply distortions. The LINK has been built from the ground up for noise-free playback.

The world of digital music playback can be confusing with so many different options to choose from: music files on PCs and laptops connected by USB or Wi-Fi; NAS drives on home networks with carefully archived CD libraries; internet radio and subscription services like Tidal, Qobuz, Spotify. The LINK is a universal solution that easily, simply and elegantly adds streaming capability from all these sources to existing hi-fi systems, giving you maximum flexibility.

If you are a music lover with a well-balanced system that has been refined to please your tastes, you’ll want the LINK.

 

NOISE IS THE ENEMY

The challenge with digital audio is avoiding noise polluting the data stream.

It is possible to take a digital signal output straight from a PC or laptop and connect it to a DAC. However, as with analogue systems, digital systems are plagued with noise. Computers have many integrated circuits and power supplies tightly packed together with software processes running that generate noise. This noise easily jumps onto the data bus that is used for moving files through the computer; this is often described as ‘parasitic’ noise which can effectively mask and blur the file being played back. The result of damaging the critical phase and timing information is a perceived reduction in dynamic contrast and a loss of musical nuance. This digital timing error is known as ‘jitter’ and if left untreated tends to give a harshness to the sound we hear.

Phase noise (blue and green areas) on an untreated PC digital output recorded on a signal integrity analyser

 
 

SIGNAL DETOX

Humans are very perceptive when it comes to phase and timing accuracy, so it is imperative to remove unwanted elements from the incoming signal that distort or disrupt the signals phase and timing. Phase accuracy is vital to a true analogue representation of your music.

The LINK has a solution to the problem of digital noise. We worked with renowned audio electronics engineer John Westlake on the LINK streamer. With over 25 years of award-winning designs to his name in digital audio, John is the perfect partner for Stack Audio and an expert in removing noise from the signal path.

The LINK has a signal detox system that solves the problem of electromagnetic interference (EMI) and jitter damaging timing accuracy:

  • Ultra-low phase noise USB audio clock
  • A jitter attenuation system that synchronizes the ethernet input to the digital audio master clock, reducing the small variations in the timing of the digital signals
  • A dedicated USB audio output that buffers the signal to purify the signal further
  • EMI filter circuitry that removes interference from the USB output

By inputting a USB stream from your laptop/computer you can take particular advantage of the Detox circuitry removing noise. All incoming signals pass through the Detox system, whether USB, Ethernet, or Bluetooth, so the benefits are audible however you use the LINK.

Phase noise on the LINK output recorded on a signal integrity analyser

 

POWER SUPPLY

Power supplies are essential to energize circuits and make electronics work. However, if they are not implemented well, they can add noise and distortion. The LINK’s advanced digital processors are powered by an extremely low noise, multi-stage power circuit to enable them to achieve peak performance. It comes supplied with a low leakage medical grade DC power supply.

  1. Nine organic low resistance capacitors help filter and purify the power
  2. Three independent switching regulators are synchronized to the audio clock. This ensures that the fluctuations of the switching circuit are in time with that of the audio clock reducing fluctuations and noise
  3. A triple linear regulated circuit purifies remaining noise
  4. Not all DACs require power from the USB input, so the LINK features a USB power switch for further noise suppression. The USB power feed is no longer active alongside the data line
 

SOLID ALUMINIUM CASE

It has long been understood that it’s a good idea to separate digital and analogue electronics. The LINK is a pure digital system housed in a thick CNC machined aluminum case preventing EMI transmission.

The LINK has been designed from the outset to be extremely low noise. No matter how well engineered, individual components will still emit EMI, creating crosstalk. To counter this Stack Audio have gone a step further using EMI absorbing materials placed in pockets inside the machined aluminium case above the EMI emitting components.

 
 

FLEXIBLE, POWRFUL, INTUITIVE

For an audio company the complexity of developing a stand-alone software eco system is substantial and it has to be kept up to date with the ever-changing landscape of file-based media services.

By using Volumio as the foundation of the LINK’s operating system, Stack Audio is able to deliver a product that can work as you want it to: an audiophile USB hub; a UPnP or OpenHome endpoint; an AirPlay compatible or Chromecast player; a Roon endpoint . In simple terms the LINK enables you to choose.

 


SPECIFICATION