The Vinyl Anachronist
by Marc Phillips
Part CXXVIII: Got Hum?
(April 2021)
Have you ever had to chase a ground loop hum? If you're into vinyl, you've probably had to deal with grounding issues one time or another. Once you get that horrible hum sound coming through your speakers, it means that your system isn't properly grounded to the earth. That's why most turntables include a simple ground wire, something that gets attached to a small lug elsewhere in your system-usually near your phono inputs on your preamplifier. Hook that wire from your turntable to that lug, and that hum should go away.
Except for when it doesn't. That's when you need to start unhooking your stereo components to discover what's causing the hum. I've wasted plenty an afternoon trying to eliminate the hum coming out of my loudspeakers.
There are plenty of things that can cause a ground loop hum in your hi-fi system, especially when you play LPs on a turntable. Loose wire connections, unshielded components near magnetic fields, and faulty wiring can all get things a-hummin'. In many cases, it's a simple mismatch somewhere in the component chain.
Let me explain. Back in college I bought my first turntable, an AR ES-1, where I had to mount and align the cartridge myself. I bought the AR from one place that had them on sale, but I didn't like their cartridge selection. I decided to get whatever cartridge I felt like getting at the time, within a modest budget, of course. A local dealer suggested a Grado cartridge-he felt they offered great value and the Grado Signature 8M would be an excellent match for the AR.
But it wasn't. Due to the unshielded design of the Grado, the AR hummed. Loudly. Since it was my first time trying to install a cartridge properly, I thought it was just me doing something wrong. Later, after I traded the Grado for an Ortofon and eliminated the hum for good, I started reading about the well-documented hum problem of the Grado cartridges with a number of turntables, especially Rega and AR. There's nothing wrong with the Grado cartridges-they sound excellent-but they just don't work with every turntable out there. A dealer should know this. That local dealer who sold me the Grado 8M should have known, too, but at least he made me a good deal on that other cartridge.
That was my only unsolved issue with a ground hum-I've been able to troubleshoot more efficiently since those early days of audiophilia. Once it was the clip from a tonearm lead that was too loose to fit snugly over the cartridge pin. Once it was an RCA jack on a preamp that was coming loose inside the chassis. Once it was an impedance mismatch between a cartridge and a phono preamplifier, and I had to borrow an expensive step-up transformer to fix it. Once it was a power transformer humming because the AC outlet was only pushing out 105V instead of 110V. I had to call an electrician for that one. I know I'm getting technical here, but I just wanted to show you that many things can cause ground hum, even if you don't play vinyl.
Still, I thought hum issues were a thing of the past. Better phono cables, better grounding hubs, and an improvement in my own cartridge mounting skills have erased the problem. Or has it? As it turns out, ground hums are not binary-where either you have one or you don't-but a matter of degree. I'm in a fortuitous spot right now since my current gig gives me access to equipment that is designed to lower the noise floor in my system. I have an AudioQuest Niagara power conditioner that reduces power surges, noise, and interference from the AC outlet. I have plenty of NCF devices from Furutech that use cryogenically treated materials to reduce noise within the system. For grounding, I have the same little green ground wire running from my turntable to my phono stage that you probably do.
I thought I was happy. I thought I had reduced the noise in my system to the point where I could move on to other interests within the hobby. I've always said that lowering the noise floor on a hi-fi system is a huge priority, since less noise allows you to hear more music, and therefore more detail, than ever before.
Over the last few years, I've noticed a strange new type of component in high-end audio systems at shows, at dealers, and in the systems of the rich and wealthy-an earthing/grounding station. When I first spotted one, a solid-looking milled aluminum box on the floor, I asked if it was the power amp. "No," I was told, "it's the earthing station." Fancy, I thought, before I moved on. Some people really want to control grounding. I get it.
But I didn't predict just how important grounding has become in our hobby in the last couple of years.
A few months ago, I was sent a complete earthing unit system from Nordost called QKORE, which I reviewed for Part-Time Audiophile. It consisted of three earthing stations-again, a solid milled aluminum brick the size of a 1,000-page hardcover book with RCA jacks on the back panel for hooking up the ground wires. These wires, looking like the typical green ground wire but with fancy custom terminations, cost $350 each. Each QKORE grounding unit came with one or two of these ground wires, but you'd need to buy extras if you planned on grounding every single component in your system. Which Nordost recommended.
Each of the QKORE grounding units cost between $2,500 and $5,000, depending upon how you want to ground your system and where you want to house the distribution block that contains the artificial earthing environment. Yes, it's a lot of money to deal with a possible hum. But once I had the QKORE in the system, along with the power conditioning and NCF devices, my system was quieter than ever before.
How quiet was it? First of all, my listening room was so quiet that I noticed I have just a trace of tinnitus, some low-level residual growl from my concert-going days when I was young. Have you ever been in an anechoic chamber, or even in the middle of the wilderness in the middle of winter? It's so quiet that you begin to hear things you don't usually notice like your heart beating or your own breathing or, in my case, that faint pink noise marking my long personal history with listening to loud music. Perhaps on headphones as well.
I could turn up the volume on my amplifier (without music playing, of course) and place my ear next to the woofer on one of my loudspeakers and I could not hear a thing. No rush, no electronic buzzing, no mechanical presence. If I got up really, really close I could hear a faint something. But no one listens to music like that. Once in a while I would hear a buzzing noise in the room and think, "Oh, here we go. There's some noise." But I'd wind up trying to locate the noise and each time I was led out of the listening room and into another room like the kitchen, where the fridge mumbled gently to itself, or I would go into a spare bedroom and find out that oh, someone left a fan on. It was never my system. It was incredible.
But all that silence comes at a price, right? The Nordost QKORE system is very expensive, but it is effective. It made a huge difference. I sent the grounding units and wires back to Nordost, published the review, and before you know it a couple of high-end audio companies asked me to listen to their grounding solutions.
The first new grounding product came from UK-based company Atlas Cables. I was sent a couple of looms (our name for a complete set of cables for a single system) of their top-of-the-line cabling, which integrated their Grun grounding system right into the jackets. Each cable has a third lead at the end, the grounding wire, which can lock to other grounding wires and eventually their earthing station, which is also a power strip. It's a lot of cables going every which way, so you'll need to sharpen your cable dressing skills, but this is a less expensive grounding system than the Nordost and came close to achieving the same levels of silence. It's still expensive, however, for those who have a modest system and want to improve grounding.
The second grounding product came from AudioQuest, a very well-known high-end cable company. This solution is far more modest and simple in application-and lower in price-since it's all about building a better ground wire. Nordost accomplished this in their QKORE system, but for $350 a strand. I did think about keeping one of those Nordosts for my turntable grounding wire and writing them a check, but I completely forgot and it was all gone.
Instead, I received two GroundGoody wires from Audioquest, the $30 Saturn and the $300 Jupiter. These aren't gussied up green ground wires, but ground wires with first class spade lugs and an attractive jacket that helps them blend in with your system. In other words, they look a lot like every other AudioQuest cable. Both made incremental improvements to lowering the noise floor. As I see it, everyone with a turntable should try the Saturn-it's affordable enough that you can buy it and return it if you don't hear an improvement. The Jupiter, however, is the one I may keep. As I see it, this is the ground wire to use on a world-class analog rig that lets you hear every single change you make to your audio system.
In the coming months, even years, I expect to hear and review and report on many more grounding products. This is a hot area of development in the industry now. Best of all, this isn't another tweaky audio trend that will be debunked in the future, leaving you with some expensive and useless toys. This is grounding, solid and proven science, and you can easily hear the difference it makes to your music.
Whether you spend $30 or $15,000, it's worth investigating.