By Anthony Chiarella
For all the times we improve our HiFis by upgrading components, some of the most satisfying enhancements are absolutely free. And perhaps no other “Tweak” offers as much sonic benefit as chasing ground noise from your sound system.
Back in the days before streaming—or even CDs—most of us suffered some sort of ground noise from our analog rigs. Between the low output of moving coils, the high gain of phono preamps, noise leakage from turntable motors, etc., most pre-digital audiophiles needed to roll up their sleeves and chase hums and buzzes from their systems. Typically, this was (…and still is) accomplished by using ground wires to connect the tonearm and/or turntable to the preamp chassis. However, there were also occasions where certain cartridges needed to be placed at a great distance from power transformers, not to mention that certain cartridges wouldn’t work with some turntable motors.
The scenario above illustrates an extreme case of grounding issues, but, to some degree, EVERY system is prone to the effects of component grounding. This means, of course, that EVERY system can be improved by paying careful attention to grounding.
For starters, let’s understand the problem. A three-prong electrical cord carries the positive (+) and negative (-) legs of the AC voltage, while the third wire is “Earth” which typically connects the chassis to true ground, which, in theory, reaches through the foundations of your home and into the earth itself. Simple, huh? Problem is, the walls of a typical house contain a birds’ nest of wires—electrical and otherwise—and some of your outlets might not make a proper, solid connection to ground. To complicate matters, not all components are grounded in the same manner, while some are not grounded at all! Throwing together bad household wiring and components, with different grounding schemes, creates a “Perfect Storm”, which allows hum and noise to pollute your system.
Fortunately, there are simple and effective solutions to grounding issues. Let’s start at the AC outlet. In most systems I’ve seen, the single biggest problem is the quality of the AC outlet. Think about it: we spend a fortune on AC cords and power conditioners, and then plug them into a decades-old AC socket with corroded conductors (which probably have little “grip” or connection integrity), and we expect our systems to sound their best? For under $15, a 20-amp, Hospital Grade AC outlet will vastly improve power delivery. Why? Well, first of all, these receptacles are much more robust than the sockets which were installed when your house was built. Heavier metal conductors (which, given the fact that they’re brand new, are corrosion-free), thicker insulators, made of superior dielectric materials, and the fact that “Hospital Grade” sockets are designed to grip the blades of the AC plug more tightly, better prevent life-saving machinery from being accidentally disconnected from the outlet. Simply put, there is no more cost-effective means of improving your system than replacing your AC receptacle.
Just as important, you’ll need to make sure your AC receptacle is installed correctly. The positive, negative and Earth wires must be connected to the proper terminals on the AC receptacle. This can be easily accomplished with an “AC Receptacle Tester” which is available at any hardware store. I bought mine on Amazon for under $7.
So, for under $25 (combined cost of AC Receptacle and Tester), you can dramatically improve the quality of the AC that reaches your system and ensure that your system is properly grounded. Congratulations! You’ve just established a foundation for greater system performance. You’ve also eliminated most of your system’s potential grounding issues! (CAUTION: working with AC power and your home’s electrical system is potentially hazardous. Please consult a licensed electrical contractor.)
Once you’ve optimized your AC, it is time to look at your power distribution. A common mistake is to use a cheap “outlet strip” intended to connect a computer, printer, etc. These devices have terrible contact integrity, tiny-gauge wiring and—worst of all—current-robbing, noise inducing surge suppression and protection circuitry.
Now, take a look at your components’ AC cords. Are they all three-prong, or are some of them two-prong varieties? We’re trying to determine if you’ll develop “ground loops” due to a combination of grounded and ungrounded components. Plug all your components into the outlet strip and power-up your system. With no source playing, and using a normal volume setting, put your ear close to each speaker. What do you hear? A gentle hissing sound is ideal, as it suggests that your system is properly grounded; on the other hand, any sort of hum indicates grounding issues.
To address ground problems, you can introduce a product like Nordost’s QBASE into the system. Instead of using any sort of filtering or conditioning circuitry, which could adversely affect power delivery, Nordost’s QB8 creates a “Star Ground” topology to optimize system grounding and minimize hum and noise, while its shape and construction are designed to control resonance and further improve sound. The real key to a product like this, is it controls ground flow between components. We can all tell how signal flows throughout our system (For example, we know the signal goes from our turntable, to our phono stage, to our pre-amplifier). What we don’t know is which direction our ground is going; although, we can pretty much tell it goes in the direction of the component with the lowest chassis impedance— meaning sometimes it can flow directly opposite of the signal creating noise and hum. As an entry point into Nordost’s AC power system, the QBASE can offer dramatically quieter and more lifelike sound quality, because it forces ground to flow in the direction of the integrated amp or pre-amp.
Ground optimization is truly a triumph of brains over bucks. With careful attention to the quality and proper wiring of your AC Cords, you can achieve a dramatic improvement in the sonic production of any system!