Dedicated power circuits

I'm am beginning the process of building a new house and I have been researching this topic over the last year. As you have likely figured out from this thread, there is no consensus about the best practices for electrical design for an audio system and a couple of my comments are in conflict with earlier responses, but here goes.

First of all I highly recommend reviewing the articles and videos from Michael Fremer regarding his electrical power experience. The links are: Fremer Electrical Video and Analog Corner Power.

Separate Audio Panel - I'm going to use the system from AudioUltra (Seattle) AudioUltra for a separate panel for my stereo room. This is fairly expensive but it's not too bad for new construction. I met both the Kingrex people and the AudioUltra people at last year's Pacific Audio Fest (they had separate booths/rooms) and I believe that they make their own panels. I talked to Rex Hungerford for quite a while and I came away with the impression that he is catering to folks that are a whole nuther level of OCD about their systems than I am. The guy from AudioUlta (I think it was DeVito) was much more down to earth and more my speed.

BTW - There are no heroic features to my current electrical setup and my system sounds outstanding. I do run a dedicated 20 amp circuit for my Krell KSA300S but the other gear is on a shared 15 amp circuit.

10 gauge wire - I've been told by several experienced people that for typical run lengths 10 gauge wire will not provide any benefits over 12 gauge. The only benefit you might receive from 10 gauge is if you have a very long run and the 10 gauge might present a slightly lower voltage drop. In my case my panel will be quite close to my outlets so I'm going with 12 gauge wire and 20 amp outlets.

Special outlets - I met Caelin Gabriel from Shunyata at the 2019 AXPONA during a slow period in the room and he was very friendly and generous with his time. The subject of electrical outlets came up and he told me that hospital grade outlets were not suitable for audio use. They are made from stainless steel and are designed to prevent corrosion from the strong cleaning chemicals that a hospital uses. They do not transfer electricity as good as a copper outlet. He said to only use outlets with copper hardware and he said that for a reasonable cost the best outlets are made by Hubbel such as the HBL5623W for 20 amp outlets. I took his advice and replaced my 20 amp outlet with this model. I don't think I heard any difference but it makes me happy.

I'm fortunate that we have our own transformer which is right next to the new house so our incoming power should be excellent. I am not going to go with any kind of power supply filtering or processing between the transformer, panel, and the outlets. I have tried a couple of power conditioners in my present setup and I have not heard a noticeable effect.

I'm going to have an emergency generator and I'm depending on AudioUltra to insure that I don't get the same problem that Fremer had. Having a dedicated panel for the audio room should completely solve that.

And finally, a philosophical note about electrical codes. I'm no electrician but I have had a lot of experience with construction and I have come to believe that electrical codes are carefully researched and very robust. You can have a run of about 57 feet on a 20 amp circuit (at full 20 amp draw) with an acceptable voltage drop of 3.6 volts. If you go with 10 gauge wire that goes up to about 71 feet. 10 gauge won't hurt anything but unless you've got very long runs it's doubtful that you would ever hear a difference.

Good luck and please report back on what you install and how it sounds.

Recommendations for power receptacles from a previous post of mine

"I do HIGHLY suggest quality recepticles (not just hospital grade). Furutech GTX-D is what I am running right now, butt also had great sound from Oyaide R1 (NOT the SWO series), Cardas, and PS Audio...though the PS Audio is the worst of the lot, but still an improvement."

I ‘ve 3 same lenght dedicated lines.

Easy to install, more if you’re - congrats- building something new.

A Doepke 3P circuit breaker and protection switch with an N common pole and 3?line Oyaide Tunami V2 cable 

-1 feeds the Atmasphere MA-1 AMP

-1 feeding Soundlab U-545 SPEAKERS

-1 feeding sources

The result is wonderful, the punch and crystal sound, speed and image is making me enjoy music.

Hope this can help. I don’t know how to insert some images, sorry

 

 

I installed a sub panel with 6/3 w/ground to the room with a 65 amp breaker in the main panel. Then I pulled off a 240v-20a for the big amps and a couple of 120v 20a circuits for the wall outlets, 120v 15a for lights. That way, instantaneous power draw could be very high with nearly no drop in voltage. Future proofing. 

@8th-note,

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Is this what you are looking to buy? You do know it is 120/240V? Best practices is to feed audio equipment, (that is connected together by wire ICs), is to feed the 120V equipment from branch circuit breakers fed from same Line. All from Line 1 or all from Line 2. Not from both.

 

You mentioned Michael Fremer’s new electrical service. All his audio equipment is fed from one 120V Line. I have no idea how big his total load is though. Just a guess a lot more than yours.

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I watched the video again today and picked up a few things I missed the first two previous times. I believe there are a few things worth noting.

Near the end of the video Fremer shows the new sub panel for his audio room. It is fed 120V only. *(1)* Electrical Inspector did make the electrician install the other 120V hot conductor. It will not be used though. I think it was just an AHJ Inspector thing. I couldn’t find anything in the NEC that requires it.)

Note the 120V feeder for the sub panel is installed in PVC conduit. All the branch circuit wiring is installed in non metallic flexible conduit.

Example, non metallic flexible conduit:

1/2-in x 25-ft Ultratite Non-metallic Schedule 80 Liquid-tight Conduit

From what I could see the outlet boxes are also non ferrous as well as the outlet cover plates. I did see something I didn’t agree with though. Two dedicated circuits for the two mono amps were pulled in the same raceway, conduit. That doesn’t follow best practices. I did notice though the 120V Hot, Neutral, and Ground branch circuit wiring used for each 120V circuit was apparently tightly twisted together. That would be a whole lot better than if single conductors for both dedicated circuits were all pulled loosely together in the conduit. That definitely is a no, no. A sure way to induce an AC voltage onto the equipment grounding conductors and cause ground loop hum.

Image of audio room sub panel, front cover removed. Note the two 120V dedicated circuits bottom right side of panel in the flex conduit connector.

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Not to bad mouth the electrician. He may have had his reasons... I did notice a few things on the installation of the new electrical service I didn’t care for.

The use of a rigid no-thread coupling on the Mast rigid Conduit. (Yeah it meets code. But...)

The use of the offset nipple into the top of the meter socket enclosure hub. Not pretty...

And I found myself scratching my head why the electrician used PVC conduit nipple from the bottom of the meter socket enclosure to the Myers Hub on the main service equipment panel. A galvanized rigid nipple would have looked a lot better, jmho... As well as electrically bonding the two metal enclosures together.

 

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*(1)* Electrical Inspector did make the electrician install the other 120V hot conductor.

I have a friend in Texas that has a 15KVA 240V to 120V single phase pad mount outdoors isolation transformer strictly for feeding his two channel audio room equipment. The electrician only installed one, Hot, neutral, and ground, conductor to feed the 120V only electrical panel. The electrical inspector made the electrician add the additional spare conductor for the other hot Line, ( for future), not used, not connected.

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