How Much Gear on a Single Power Outlet?

[bonestar]

Just wondering how much studio gear I can run off a single power outlet. It's a small studio - three 4 channel mic pre's, SSL Digital interface, Dynaudio BM6A powered monitors, computer, monitor, a few compressors, a couple of synths, couple of small mixers, a couple of small lamps. Nothing that draws a whole ton of current.

I do also run a small guitar amp though, and there's my problem - there are two electrical outlets near my mix station and each is on a different circuit. So I get ground loop problems and get shocked when I touch my lips to a microphone at the same time as I'm touching my guitar - mic's plugged into the board on circuit 1, guitar amp plugged into circuit 2.

The immediate solution is to just run my guitar amp off the same circuit as the board, but i'm wondering if it might be better to run everything off a single circuit/outlet? No big power amps, no lighting rigs, etc. Just a recording setup.

Follow-up question - how can I get enough plugs coming off one outlet? Is daisy-chaining power bars a bad idea? I've done it before without any problems, but am I just asking for trouble?

Any input would be much appreciated.

Thanks.

[crosscutred]

If you're getting shocks there is something wrong. Get that checked out.

I read that the BBC ob truck that my 40 channel desk came from could be run from one 13 amp socket. So I wouldn't worry too much.
You can work out how much current you need from the gear you have. What does each piece of equipment require in amps? Add them up.

[nosebleedaudio]

First: you have a grounding problem, NOT a ground loop.
2nd; yes I would have all gear on same outlet.
Is the gtr Amp grounded?
The main problem is something is NOT grounded.

[Bill@WelcomeHome]

Originally Posted by bonestar

Just wondering how much studio gear I can run off a single power outlet.

I do also run a small guitar amp though, and there's my problem - there are two electrical outlets near my mix station and each is on a different circuit. So I get ground loop problems and get shocked when I touch my lips to a microphone at the same time as I'm touching my guitar - mic's plugged into the board on circuit 1, guitar amp plugged into circuit 2.

Follow-up question - how can I get enough plugs coming off one outlet? Is daisy-chaining power bars a bad idea? I've done it before without any problems, but am I just asking for trouble?

If your circuit breakers are US residential 120 volt 20 Amp, figure that you have roughly 2000 watts to play with. (There is more but it never hurts to leave some headroom.) If you look n the back panel of most gear, it tells you how many watts are used. Add them up. (We're not talking about RMS watts from a guitar amp, like, "I've got a 100 watt Marshall", we're talking about the number written on the metal tag, usually near the AC cord.)

The shocking and the ground loop concern me, but first lets check the "shock" part. Could it be static electricity, from being in a dry room because the furnace has been running for weeks? If definitely not, get a circuit tester from the hardware store. They run around five bucks. Home Depot - 3-Wire Circuit Analyzer Voltage Tester customer reviews - product reviews - read top consumer ratings You use this to check that both outlets are properly wired. You should also not be seeing a ground problem. Ground problems have to do with different distances to ground and are typically related to -long- distance differences, which can be dangerous. However, there should only be one path to ground in any audio system.
What you call 'power bars' are usually crap, and come in too many different crap configurations and wiring to generalize. Okay on their own, but I'd not daisy chain them. They also tend to be rated at 15 amps, so that might factor into what you do, too. (Technically, the standard outlet in a home is only rated at 15 amps, too. But it is common to have 20 amp breakers.)

[loujudson]

I run a full sound system on one 20 amp circuit (but rarely do rocknroll). Can keep 600 people dancing. Your studio can do the same thing, one circuit, no shocks.

[Ike Zimbel]

+1 to everyone that said that getting shocks when the guitar amp is in use is WRONG. The first thing I look at in a guitar amp is the AC plug. Does it have the ground pin still in place (if it had one at all)? Does it have the original molded plug, or a replacement? If the plug is a replacement plug, ALWAYS open it up and make sure that it is wired correctly:
Green Wire = Ground = Green screw
White or Blue wire = Neutral = Silver screw
Black or Brown wire = Hot = Gold screw
Make sure the wires are cut and stripped to the correct length (most plugs actually have a "strip gauge", a mark or trough showing you how much insulation to strip off).
Make sure the wires are not frayed, with stray strands sticking out.
Make sure the screws are tight.
And finally, make sure the covers are on properly and the strain relief is gripping the cable.
Best,
Ike

[bonestar]

Thanks guys.

I'm definitely going to pick up the circuit tester. I get the same issue no matter what the amp is I'm running, so if there's a grounding problem it's definitely the outlet/circuit and not the amp.

So what is the best method to run 25-or-so plugs (assuming total current draw is within acceptable limits) into one outlet without daisy-chaining power bars? Just a straight power extension cord that has a 3 outlet end than then run a rackmount power unit (like a Furman) off each?

[bonestar]

Originally Posted by Bill@WelcomeHome

If your circuit breakers are US residential 120 volt 20 Amp, figure that you have roughly 2000 watts to play with. (There is more but it never hurts to leave some headroom.) If you look n the back panel of most gear, it tells you how many watts are used. Add them up. (We're not talking about RMS watts from a guitar amp, like, "I've got a 100 watt Marshall", we're talking about the number written on the metal tag, usually near the AC cord.)

I'm seeing current ratings. At 120V, it seems that:

API 3124+ (x3) draws 0.5A (x3) = 1.5A
LA-610 draws 0.4A
LA3A (x2) draws 0.125A (x2) = 0.250A
SSL Alpha-Link draws 0.6A
Avid Eleven Rack draws 0.5A

That's my main rack. 3.25A total. Even if my other stuff (keyboards, computer, guitar amp, etc.) adds up to three times that much (which I doubt it would), I should still be well within the limits of that one outlet.

...I assume.

[Bill@WelcomeHome]

Originally Posted by bonestar

So what is the best method to run 25-or-so plugs (assuming total current draw is within acceptable limits) into one outlet without daisy-chaining power bars? Just a straight power extension cord that has a 3 outlet end than then run a rackmount power unit (like a Furman) off each?

Hmmm... below you list a handful of products, here you say that you've got 25.

Probably not the answer for you, but I run dedicated power lines from the box to the room in question so that i know that nothing else is on that circuit/s.

Another issue with hardware store extension cords or power bars is the cabling. It is often 16 or even 18 gauge. I make my own extensions using 12 or 10 gauge wire. You can gang together multiple quad boxes if you want, but I find it more convenient to be able to run multiple cords around the room, so I have several. What some people do it to mount a twistlock connector on each box and make up some daisy-chain cables, but that gets expensive and creates a proprietary situation. I try to stay away from that in simple home rigs if I can.

Don't buy rack mounted extension cords unless you've got money to burn, or want the convenience of turning everything on with one big thump. They usually contain nothing any different than you find in a standard $10 hardware store strip.

[bonestar]

Originally Posted by Bill@WelcomeHome

Hmmm... below you list a handful of products, here you say that you've got 25.

That's just my main rack. I havn't looked up current draws of everything else, but a lot of it would be pretty low draws. A bunch of wall warts and whatnot. In addition to the main rack, I also have..

Dangerous D-Box
Distressor
Mackie 12-channel mixer
Korg MicroKorg
Dave Smith Tetra
RNC Compressors (x2)
dbx Graphic EQ
Rolls headphone amp
ART line mixer
Computer
Computer monitor
Guitar Amp
Pedal-power power supply, running a bunch of effect pedals
Desk lamps (x2)
Printer

That's 25 right there. I probably have a few more that I'm forgetting. Just stuff in my immediate mix area.

Probably not the answer for you, but I run dedicated power lines from the box to the room in question so that i know that nothing else is on that circuit/s.

Ha. Yah, probably not practical for me.

Another issue with hardware store extension cords or power bars is the cabling. It is often 16 or even 18 gauge. I make my own extensions using 12 or 10 gauge wire. You can gang together multiple quad boxes if you want, but I find it more convenient to be able to run multiple cords around the room, so I have several. What some people do it to mount a twistlock connector on each box and make up some daisy-chain cables, but that gets expensive and creates a proprietary situation. I try to stay away from that in simple home rigs if I can.

OK.

Don't buy rack mounted extension cords unless you've got money to burn, or want the convenience of turning everything on with one big thump. They usually contain nothing any different than you find in a standard $10 hardware store strip.

Yah, I already have a few though. I've come to learn that since buying them. So, if I were to get something like this:

2 ft. Red and Black 12/3 STW 3-Outlet Extension Cord-AW62612 at The Home Depot

...and then run the Furman power strips off of that, am I good?

I had no idea that just powering stuff up could be so complicated. I've been recording for decades. Before the internet I would have just plugged everything in and hoped for the best. Now, I need to know the right way damnit!!

[Ike Zimbel]

"Yah, I already have a few though. I've come to learn that since buying them. So, if I were to get something like this:

2 ft. Red and Black 12/3 STW 3-Outlet Extension Cord-AW62612 at The Home Depot

...and then run the Furman power strips off of that, am I good?"

Yes, and by doing that, you are essentially star grounding your room.
Best,
Ike

[bonestar]

Thanks guys!!

[nosebleedaudio]

Been doing the same thing for years, works Great a last a LONG time..
But I did electrical works for several years so it was no big deal.
Can do this one of two different ways..
My first choice is: get some 12/3 SO cable from Home Depot ect along with 2 4" Deep Square boxes, 4 GOOD 15amp duplex plugs (Hubbell or equiv.) 20 Amp versions are better for the superior connection.
A single 4" Square box in a minimum in my book...
Then you have 4 or 8 GREAT AC outlets, power amps and console plug directly in, outlet strips go in 2nd...
Most outboard gear, mic pres, compressors ect draw very little current, less than a 1/5 amp..

By the way, most may OR may not know this but a typical 15 amp plug is for BOTH outlets total...OR 7.5 amps per..

[Minion]

At my old jam space we had this exact same problem ...... The guitar player/singer would get shocks off of the mic and guitar when touching both , the PA and the Guitar amp were plugged into different outlets .....

From what I remember the problem was that one outlet had one phaze of the AC tied to ground as neutral and the other outlet had the other phaze tied to ground as neutral , so there was a 115v difference in ground potential between the 2 outlets ......

That could be the source of your problem ..... Maybe get one of those outlet testers to see if the wiring on the two outlets is correct .......

[natefrogg]

it may be beneficial to get a kill-a-watt device, you can plug each device you use into the kill-a-watt, power the device on and wait for it to get going, and check how much wattage and amperage is being pulled

i know this won't fix the issue with the amp, but it is good to know how much juice you are pulling from your circuits imho

personally, i do not like to push over 80% of what the circuit can handle, my house is old and is mostly just 15 amp circuits...also a good idea to use heavy gage power cables and extensions if you can, 14 at a minimum, 12 is better if you can do that

[waveterm]

You should be ok with your amount of gear on a single outlet.

I run over 120 pieces of gear on a single 10 amp 230V outlet.

My Fairlight CMI has a separate outlet though, it draws 3 amps.

WT