2. misc-audio
  3. 156719-128813

Dedicated 20 amp circuit - Electrician laughed!

I brought my electrician out to my house today to show him where I would like to install a dedicated 20a circuit for my system.  He laughed and said that's the stupidest thing he's heard and laughs when people talk about it.  It said, if you're going to do it, you have to have it separately grounded (shoving a new 8 foot rod into the ground) but even then, he sees no way there can be an audible improvement.

Now, he's not just an electrician though. He rebuilds tube amps on the side and tears apart amps and such all the time so he's quite well versed in audio electronics and how they operate.

He basically said anyone who thinks they hear a difference is fooling themselves.  

Personally, I'm still not sure, I'm no engineer, my room's not perfect, and I can't spend hours on end critical listening...  But, he does kinda pull me farther to the "snake oil" side and the "suggestive hearing" side (aka, you hear an improvement because you want to hear it).

I'm not taking a side here but I thought it was interesting how definitive he was that this not only WILL not make a difference but ALMOST CANNOT make a difference. 
dtximages
djones51
4,947 posts
 
Theories are never proved. Ohms law holds in a ohmic device. Calling it a "law" was simply a convention it could have been called Ohms obersvation or Ohms theory. 

http://oer2go.org/mods/en-boundless/www.boundless.com/physics/definition/ohmic/index.html

handymann
380 posts
 
I have three dedicated lines in my sound room.  I’m running two Krell EV 600 monoblocks. Each has its own 20 amp circuit, with hospital grade outlets and 10 gauge wire. I’ve never tripped the breakers, but am more cautious with my hearing than I used to be. The rest of my room is on another dedicated 20 amp circuit.  All are wired to the same side buss. I however do not have a dedicated ground.  I’ve never experience any ground loops or hum and am very thankful. 
dimora's avatar
dimora
61 posts
 
He’s Not really correct.  I’ve had huge improvements going to a dedicated circuit when OTHER ITEMS on that same circuit are noisy.  Fluorescent lights, hair dryers, microwaves and vacuum cleaners are quite noisy and will cause visual (TV-projector) mouse as well as audible noise.  A dedicated circuit can help in those cases.

A good wiring technique (USA) is to put the noisy items on one “leg” in the electrical panel and keep the audio items on the other “leg”.  (In the USA, boxes are fed with dual 120V wires or “legs”; most circuits only use one, unless they are a 220V circuit.  Air conditioners, stoves, air compressors, welders are 220V and all else is 110).  The wiring strategy is to keep bathroom circuits (hair dryers)  and living room / bedroom / hallway circuits (vacuum cleaners) and buzzy lighting circuits (fluorescent) on one leg and audio on the other.

His assumption in needing to run a new ground is based on issues with ground loops.  If the length of wiring on all audio circuits to the box is the same, ground loops are often avoided until you introduce coaxial cable into the mix.  Use isolators if that happens.  RCA cables (subwoofers) also cause ground loops; in that case consider higher-end gear with XLR interconnects or use isolators on the sub RCA’s.
dimora's avatar
dimora
61 posts
 
Also, high end gear can have huge current draw, especially with Class A gear.  Sharing circuits can cause tripped breakers or blown fuses.  If your lights dim and flicker during loud passages, you need a dedicated circuit.
geoffkait's avatar
geoffkait
23,365 posts
 
Some Laws are meant to be broken. I broke two this morning and it’s not even lunchtime yet. But some theories have passed from theory to Law. To whit, the Laws of Thermodynamics. We also have F = ma 

https://en.wikipedia.org/wiki/Laws_of_thermodynamics
More to discover