The power supply that runs most audio equipment today is called a “linear” supply. It was designed in the 1920s, when most people first used electric devices in their homes. It hasn’t changed much. Recently, some audio devices started using something different – a “switching” supply. That design was developed in the 1950s. The Rhythm 1.1 preamplifier uses the new GreenForce™ power supply. Bob Backert patented GreenForce in 2013.
GreenForce is the only power supply in the world that can run entirely on V-CapTM capacitors, the finest type of capacitor in audio today. More about that here. In contrast, the power supplies in almost all audio equipment use electrolytic capacitors, the worst quality capacitor made today. It’s not because they want to. It’s because they have no other choice. With GreenForce, that changes. Let’s talk about why “Green” and “Force” are in the name of this new kind of power supply.
GreenForce allows Backert Labs to eliminate electrolytic capacitors from the power supply. Bob Backert wanted to achieve this because electrolytic capacitors are famous for their disappointing sound quality. That sound quality problem is why many manufacturers use small, high-quality “bypass” capacitors along with their electrolytics. But why do they use electrolytics at all? Because they need very large capacitor values that only electrolytics can provide. GreenForce uses much smaller values, allowing high quality capacitors to power the unit. In addition to sounding better, eliminating electrolytic caps is also a win for our environment. That’s because electrolytic capacitors contain chemical sludge that is classified by manufacturers as hazardous waste. The power supply is where you’ll find the largest electrolytic capacitors in any piece of audio gear. By eliminating them, the GreenForce power supply makes the Rhythm 1.1 “green” in a whole new way. More on the elimination of electrolytic capacitors here.
Unlike traditional power supplies, in which a capacitor passively bleeds power out when the amplifier demands it, GreenForce is the first and only power supply to actually force power into the load (the amplifier) at all times.
The Benefit: This makes GreenForce more nimble, more accurate than conventional supplies. This is key in immediately responding to changing current demands, such as the larger amount of current required to reproduce a loud bass drum.
Example: Imagine that a power supply capacitor is actually a barrel full of water (the water is the capacitor’s power). A hose coming from the bottom of the barrel lets the water drain out. This is the way that typical audio components get their power — it “drains out” from the power supply capacitor. When it gets empty enough, the barrel / capacitor is refilled with more water / power. Now imagine that the barrel is low on water at this very moment. And right now, a powerful bass drum strike happens in your music. Because the weight of the water is less, the pressure of the water coming out of the hose will be weaker at this critical moment. The capacitor’s ability to immediately provide the required power for that bass drum strike will be impaired. Full pressure will only be possible a moment later, after the barrel has been re-filled with water.
GreenForce changes that. GreenForce is like placing a lid on the water, and steadily pushing the lid down as the water comes out of the hose — forcing the water out at all times. Now, the pressure of the water coming from the hose will remain steady, even when the barrel is getting low on water. This is similar to the power produced by the capacitor in GreenForce. No matter how much power your music calls for, and no matter when, it’s right there. Power with true force behind it, at all times.
The GreenForce™ power supply gives sound equipment improved dynamics — the lightning-fast changes in volume that all instruments and singers on a recording are constantly employing to give music its drive and emotion. GreenForce also improves soundstage, with a more accurate and spacious physical presentation.
The GreenForce power supply gives the Rhythm 1.1 something else as well — rhythm. Plucking, swinging, rocking, every which way. Your favorite music will pulse, propel you, move you, like never before.
Why Power Supplies Matter
The power supply is surprisingly critical to the accurate reproduction of music. Read why here.
GreenForce uses smaller capacitor values. To put that in context, the values in a GreenForce power supply are usually around 0.5% of the value required by a normal power supply. A typical tube preamp might use 100 or 200uF in the power supply, or even thousands of uF (microfarads, a measure of capacitance). Our Rhythm 1.1 uses less than 1uF. GreenForce has nothing in common with a switched mode power supply, and shares only a few similarities with linear power supplies. It achieves isolation from the AC line the same way a linear power supply does, by starting with a typical transformer. GreenForce provides better current linearity, feeding the regulator with “right now” current more nimbly than other power supplies. For more, visit the GreenForce website, here.