Hi all.
I'm rewiring a small room that I plan to use for my music space, and I'm wondering if anybody has any advice for proper wiring, to avoid potential issues with noise, humms, and buzzes coming through my amp, due to improper grounding issues, etc. I plan to have an isolated circuit just for my guitar amp and pedals.
Any thoughts, considerations, or advice is appreciated.
Thanks!
It’s similar to wiring a studio, something I’ve done. A lot depends on budget and how much power you need. For lowest hum and noise, an isolation transformer that converts standard AC to balanced power will reduce hum and noise by about 8-12 dB.
There are installed, wall-mounted isolation transformer systems from companies like Equi-Tech, and there are also rack-mounted isolation transformer systems from Equi-Tech and Furman, possibly others. A tech can also modify something like a Sola isolation transformer, but it’s very expensive, and the transformer will need its own soundproof location. I’ve done this, and it was a PITA, but at the time these other units weren’t on the market.
Balanced AC power reduces noise using the same principles as humbuckers and balanced audio lines.
The main advantage, beyond cleaning up the signal fed by the power company, is that the noise cancelling resulting from balanced AC also means a significant reduction in noise generated from power cords into adjacent signal cables.
These systems are FAR different from mere AC “conditioners” and filters. When my first one was installed in my studio 15 or so years ago, my tech measured an 11 dB reduction in noise on the oscilloscope. Yes, actual science and testing confirmed the facts.
As I said, if you do this, get one that makes enough juice for your gear, call the manufacturer, ask questions. Both Furman and Equi-Tech have knowledgeable techs who’re actually helpful.
So that’s the ideal situation. It’s also not a cheap solution.
And you still need to pay attention to good grounding, because balanced AC doesn’t cure ground loops. It just makes things quieter once you’ve got everything else wired properly.
There are cheaper solutions that don’t involve balanced AC, that will also help even if you go balanced AC down the road! And you may not need a dedicated AC line to your room, although that certainly is not a bad idea! Here are a few:
Use a good power supply with your pedals, with isolated outlets, such as the Voodoo Labs stuff. I like the V-L over the Strymon I also had because it has a transformer. I had switching noise issues with my Strymon, and went back to Voodoo. I’m sure there are other good ones, but bottom line is true isolated, regulated outlets on the pedal power supply. If you can avoid using wall-warts, do so. They generate lots of hums and buzzes that your cables and some pedals will pick up, and send along to other gear.
Use good quality, low capacitance, shielded cables, especially near AC power cords. The shielding matters, and you can find plenty of information on the types of shielding, their pros and cons, on the web.
With my own amps, I also use a product from Furman that has a power reservoir that delivers juice faster to the amps, and improves the sound of higher powered amps. It’s less noticeable on lower powered amps. After a ridiculous amount of experimentation, I found that AC cords matter. I think that the most important thing is the wire gauge, however the ones I use are also shielded. Unbalanced lines used in guitar gear will pick up noise radiated from unshielded AC cables. In any case, the heavier AC cables have made a difference on my amps, and I’m so convinced by this surprising and counter-intuitive experience, that I now power every piece of gear in my studio with cords like these, and am getting my best recorded sound in the last 30 years, with the least noise.
Now, if you don’t want to go down a very deep and expensive rabbit hole, and your livelihood doesn’t depend on recording, please, disregard a lot of the above unless you have serious AC power problems!
The most important difference is made simply by paying attention to powering your pedals properly, and grounding. If you have signal going to more than one amp, make sure that one signal line is properly ground- isolated from the other. There are plenty of little problem-solver boxes from companies like Lehle that are sonically transparent, for lots of these grounding issues.
If you use effects loops on your amps, this is doubly important!
Finally, most AC “conditioner” products are a waste of money. They can’t solve grounding issues. They don’t isolate the line from AC noise. They don’t regulate the AC power. There are good units that do this (though they don’t solve ground loop issues), from pro companies like Furman, but the useful ones are at the upper end of their product lines, and the cheaper ones are just outlet boxes with lights (not that there’s anything wrong with an outlet box with lights, if that’s what you need!).
Hope this helps!
