2. misc-audio
  3. 193545-178608

AC Power

I have a relatively nice system, but have done nothing with my AC power, with the exception of upgraded PC’s and a cheap iFi plug in power conditioner. My question is multi fold… do I need to do something, and if so what? Dedicated line (15A or 20?)? Quality power conditioner? Both? Which one first? How do you tell?

My system is a combination of HT & 2 channel & I tend to use both simultaneously as I like to watch sports while listening to music.
My amp is (I think) a relatively low draw… Moon 330A, Rythmik sub, BHK pre, Aurender, Qutest w/Sbooster, R11’s. No high power amps are in my future & never listen above 75db. I do currently plug my amp directly into the wall. All my wall warts are gone. For my HT, add a 75” Sony TV, Marantz 7015 AVR & a Klipsch sub (although at zero volume the AVR & sub should not come into play).

I am considering buying the Furman IT-Reference 15i or 20i first as they are well reviewed & are priced very well on Amazon ($1,400 / $1,900). Before I pull the trigger, should I go dedicated power & at what amperage (my nephew, an EE & audiophile thinks I am drawing no more than 5 amps) as that will dictate the Furman model?

Interesting, my nephew thinks neither are worth the investment. His statement: “Do you have appliances on the circuit now? What kind of interference can they inject?...voltage drops would come from current draws...which trip breakers.
Not steady 60hz a good power supply handles. So it all comes back to was the power supply engineer dropped on his head as a child.”

”Personally I think it’s something audio people do when they have run out of gear to buy.”

Any thoughts or recommendations would be appreciated. Thanks!

 

signaforce
jea48
4,689 posts
 

So I guess that this means that the 240A breaker for my drier is using both legs?

Correct.

Hot L1 leg to Hot L2 leg measures 240V, nominal.

L1 to neutral as well as L2 to neutral measures 120V, nominal.

And also: the way you explained that is that the top most breaker on the left side and the top most breaker on the right side are both on the same leg?

Correct. Both are fed from Line 1 (L1) bus, leg.

 

(And from there on all the way down the legs alternate in pairs of breakers.)

Example for illustration purposes only.

Single phase 240/120Vac load center with 200A main breaker

Note the turned out horizontal bus tie breaker connection tab that is part of the left and right vertical bus bars.

Circuit breakers plug on to the bus bar tie tabs.

The left vertical bus bar is Line 1 (L1)

The right vertical bus bar is Line 2 (L2)

Breakers Left side. ............. Breakers right side

Top breaker L1 .............................L1

................... L2 .............................L2

................... L1 ............................ L1

................... L2 ............................ L2

................... L1 ............................ L1

....................L2 ............................ L2

An so on to the bottom of the panel.

No matter where a 2 pole breaker is plugged onto the breaker connection horizontal bus tie tabs the load side of the breaker is 240V nominal.

Might be Top connection of breaker L1 and bottom connection L2.

Or it could be top connection of breaker is L2 and bottom connection is L1.

It just depends on where the 2 pole breakers are located in the panel.

.

jea48
4,689 posts
 

@gdnrbob , thanks for the kind words.

.

erik_squires
16,644 posts
 

However, I had read in other threads on power that one should avoid installing your dedicated audio circuit on a leg with major appliances. Given what you said, I guess that is not possible.

 

I agree that this seems impossible. Your HVAC, electric range, water heater, etc. are all going to be 240V, and therefore on both legs. Small window AC units, hair dryers, toasters, fridge and microwave will be exceptions, but ideally your 120 V AC lines are balanced so that about the same amount of current flows on each leg, so not sure why or how you’d do this.

Ahem... which is why I buck the trend and emphasize voltage regulation over isolation. If you can do both, even better. wink

erik_squires
16,644 posts
 

It may be worth noting that tightly regulating your AC may be more important to more classic designs.  

Gear with linear power supplies with DC rails that are always some proportion of the incoming AC line (i.e. linear amplifiers) will suffer more than more modern power supplies like in your TV or PC.

immatthewj
2,842 posts
 

Thanks, @jea48 , that explanation and illustration made it so perfectly clear that even I could grasp it.  

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