What is the difference between a linear and a switching power supply?

Switch-mode power supplies (SMPS) are commonly used in wall wart and external brick style power supplies. The advantages SMPS have over linear power supplies is that they are significantly smaller, significantly more efficient, operate with much less heat, and are significantly lower cost to manufacture. Smaller, cheaper, and more efficient...what's not to like?

The dissadvantages of SMPS is they have significantly more noise than linear power supplies. The best highest technology SMPS have peak-to-peak ripple (noise) roughly equal to the most basic of linear power supplies. But ripple is not the only noise SMPS produce. In addition to producing dirtier power they also radiate inductive noise that can be picked up by analog cables and components and they dump noise onto the common AC ground. The inductive noise and ground noise SMPS produce contaminate any component in physical proximity and any component that is plugged into the same AC circuit.

Also, when compared to high-performance linear power supplies, SMPS have very slow dynamic response. When reproducing music, slower power supplies distort dynamic passages, mask micro-details and micro-dynamics, and distorting the time and tune. When reproducing video, slower power supplies make colors appear washed out, blur micro-details, and cause motion to be less fluid.

How does a low-noise power supply improve computer performance?

All computer communication works on a system of checks and error correction (check sum). If a packet of data doesn’t pass the check, a new packet of data is sent to replace the original. The lower the power supply noise, the fewer bit read errors, the fewer errors to correct, and the greater the system resources.

When you free up system resources with a cleaner power supply a computer will perform as if it has a faster processor, faster storage drive, and more RAM. When a low-noise power supply is used, the result is more liquid and articulate sound and motion. 

Don’t batteries have the purest DC power?

Though better than the inexpensive external switch-mode power supplies that come with many audio, video, and computer products, battery performance can’t compare to the performance of an ultralow-noise linear power supply.

Batteries use a chemical reaction to generate DC power, and each chemical reaction from each type of battery has its own audible noise signature. This is why a specific type of battery, such as LiO4, sounds better than another type, such as SLA. The noise level of a battery also changes significantly during different phases of the discharge and recharge cycle, making batteries an inconsistent-sounding power source as well. 

Most audiophile battery powered systems sound quite bad during their recharge cycles and batteries require the additional expense of replacing them every couple of years. Batteries also have much slower dynamic response than a good linear power supply. Their slower dynamic response results in batteries sounding slower, less dynamic, less articulate, less intense, and relatively lifeless.

If battery power has the lowest noise, then why do the military, aerospace, and telecommunications industries only use them for portable devices? 

What about degradation caused by heat?

Most of our competitors use internal heat sinks that heat up the other parts in the chassis and rely on convection through small vent holes to remove the heat.

We heat sink hot parts directly to the exterior of our chassis. This topology conducts heat from the interior to the exterior utilizing the entire exterior surface of the chassis as one big heat sink. By minimizing heat buildup inside the chassis we both lower noise and extending parts life.

Our power supplies are engineered to last for over a decade.

For more information on power supplies refer to our Audiofiles blog.