UpTone Audio UltraCap LPS-1.2
It is true that low noise is important to power supply performance, and we parallel a pair of the world’s lowest noise (0.8µV/RMS) integrated regulators–the extraordinary Linear Technology LT3045–for the 1.1-amp output of the UltraCap LPS-1.2. Yet just producing a low noise output is not what sets the LPS-1.2 apart from other linear power supplies.
Components that an external DC supply will be used to power already have their own low-noise voltage regulators inside them (most of which are nowhere near as quiet as those in the LPS-1.2), so the audible advantage from using this UltraCap™ power supply—versus a stock PS or a competitor’s LPS—is not entirely about low noise.
Rather, the two main advances of UpTone Audio’s groundbreaking new power supply are:
1) Speed and ultra-low output impedance over a broad bandwidth. (Battery supplies are poor in this regard; And many traditional traditional transformer/diode/capacitor/regulator linear PS units rely on big banks of filter caps to smooth what the regulator sees—which impacts speed and impedance.)
2) 100% galvanic isolation from the AC mains at all times. While one bank of ultracapacitors is supplying output, the other bank is charging. The output is never connected to the bank that is recharging, and the sophisticated design ensures silent and smooth transitioning from one bank to the other.
The most important result of the isolation afforded by the UltraCap™ LPS-1.2 is that it completely blocks the path of AC LEAKAGE CURRENTS. Some more in-depth information on the subject can be found on the Swenson Explains page, and here is bit more condensed explanation of this important topic—also written as a forum post by John Swenson:
The PRIMARY purpose of the LPS-1.2 is to break leakage current induced ground loops, (which exist in almost all systems), and the fact that the output is isolated from the input (thus not affected by noise of the feeder supply) is a bonus, not a primary goal. Of course the LPS-1 has a very low noise, very low impedance output as well.
There are two very different mechanisms by which an AC power supply can interact through the AC mains:
1) traditional ”noise injected back into the AC line.” This is easy to measure, easy to grasp what is happening, and many devices exist to try and filter out this sort of noise.
2) Leakage current, this is created by capacitances between the AC line and the DC output of the supply, it ALWAYS exists but varies from supply to supply. This is hard to measure, hard to grasp what it is and how it propagates through a system. After everything else is taken care of the leakage current is still there, I consider it to be one of the last great untouched detriments to obtaining best sound.
Both #1 and #2 exist in almost any system to varying degrees. Since there is already a large body of knowledge and products to deal with #1, I set out to work on finding ways to deal with #2. The LPS-1 is the first fruit of that work.
Leakage current has always been there, but has not been a big issue until recently for two reasons:
A) it is fairly low level in most systems so its effects have been masked by all the other problems preventing our systems from being their best, as these other sources of problems have been identified and addressed, the sonic results of the leakage current are now much more obvious.
B) leakage current from SMPS is usually much higher than from LPS, so the inclusion of computers (which are usually run from SMPS) into systems has greatly exacerbated the sonic detriment due to leakage current.