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hey guys,
got home tonight, put my monoblocks on one receptacle, kept my front end on the other receptacle, leaving the third receptacle empty (i actually had to do this twice to test both), and the hum is gone!
so, does this mean i just need to have the electrician back to put that third line on the same "leg" as the other two lines? do i still need to check polarity?
Follow Ups:
somewhere along this discussion, someone mentioned that a balanced power unit would solve the ground loop hum. i'm actually running a balanced unit on both my preamp and cd player, but the hum still exists. when i unplug the interconnects from the amps, i get no hum. is this info not correct?
1. Better line regulation: Ground and supply references get more stable. This is hugely important to accuracy. For example much of the so called "digital hash" caused by sharing analog equipment with digital, like a PC as an extreme example, is likely mostly ground bounce from the digital loads causing crosstalk in the analog systems through it's power supply rails.
2. Better load regulation: Power is more readily available to power hungry devices. Peak load demands are more accurately satisfied leading to better load driving capaility. In English....your high power amps won't be nearly so likely clip and thus distort in demanding musical situations if you do it right.
As has been pointed out by previous posters the tradeoff is ground loops are created, but you can do stuff to minimize the effects of this tradeoff which in most cases make it wa worthwhile tradeoff. Flea power systems might be the exception that can better get away with the single outlet approach.
Minimizing impedance between points in the loop keeps loop symptoms down. Why? Because a lower impedance is harder to develop a voltqage across. If no noise voltage can be developed due to ultra low impedance interconnects, then no noise contribution due to this ground loop is then negligible. This is accomplished by using the fatest guage wire possible and guaranteeing top quality connection points.
The other problem with dedicated lines is the noise immunity is not as good. Deal with this problem as follows: When routing the lines remember to keep loop area as small as possible when concerned with nearby fields, but this must be tempered with making sure the inductive coupling between each line is not high meaning they can't be too close to each other either. I think if you can manage to seperate each seperate line by several inches from the others while at the same time routing the whole bunch free of strong electrical disturbances you can achieve the best noise performance this seperate line tradeoff will allow.
This means they produce little or no power supply electrical noise. There would not likely be any advantage in noise reduction by running each monoblock on its own circuit. There will still be an advantage to running the power amps from one dedicated circuit and the other equipment from another, to keep the noise from the other equipment out of the power amps.
However, it would be good to understand your hum problem, and have the extra circuit available for future use. I would definitely check the wiring to make sure there is not an error, and have the third circuit moved to the same AC leg as the other two whenever it is convenient. Once you have checked for wiring errors, it would be interesting to try connecting all the grounds together at the outlets, as jneutron suggested (DON'T do this before the wiring is checked!). Another inmate who is a licensed electrician (jea48) has stated in the past that this is OK per code, but you would need to confirm this for your jurisdiction if you wanted to make it permanent.
Please understand that there is a ground loop whether you use one or two circuits for your power amps, or even if you run your whole system from a single circuit. The loop includes your equipment power cords. Adding the dedicated circuits increases the extent of the loop but does not change the fact of its existence. The only way to break the ground loop is to disconnect the AC safety-earth from some of the equipment. This is dangerous and I do not recommend it.
I've got four separate dedicated lines, and have no audible hum. There are two pairs of lines that were added at different times and that were routed differently, so there is plenty of opportunity for hum induction from stray magnetic fields. Do your lines go near any appliance that draws a lot of current, such as a hot water heater? Please also describe the installation of the outlets in more detail. Are they in metal or plastic boxes? In single boxes or a ganged box?
We pretty much now know Steve does not have 3 dedicated circuits.
We know that the 2 gang box for two of the 3 circuits is a 3 wire multi-wire branch circuit.
We know that there is only one equipment grounding conductor for both duplex outlets.
We know if Steve plugs in his two amps into just one of these circuits, (one duplex), he does not have the hum problem.
We know if Steve plugs an amp into each of the duplexes he gets a hum...
We have been calling this a ground loop hum....... Hum yes, but maybe not from a traditional ground loop. Any ideas? Your thoughts......
Jim
The Canary amps use choke-input power supply filters, and draw close to sinusoidal current from the AC, according to their web site. This means the neutral current at idle will be very small: essentially the difference between two similar devices made of real-world components.
It seems plausible that this arrangement would cause 60 Hz noise to be induced in the shared ground conductor, depending on how the wires are arranged inside the cable. This explains the problem if there is still a ground loop involving the source component and the power amps. We are assuming all of Steve's components are grounded, but there are some highly-regarded pieces that either use two-wire power cords, or do not connect the ground of a three-wire cord.
My experience is with separate cables for each circuit and does not apply here.
need to update my profile. i've got a pair of canary audio 160 monoblocks (they are awesome!).
ok, so i guess i need to go back and read through that long document, get the polarity check device, and at some point, ask an electrician to move that third circuit onto the same leg.
it honestly sounds really really great just using the two circuits. i probably didn't need that third circuit.
my lines travel along the outside wall of my condo, they don't travel near any appliances. the outlets are installed inside the drywall, using some type of metal box i'm assuming, with oyaide R1 outlets and nylon face plates. there are two circuits in one ganged box and the third on alone by itself. the two that are together are on different legs.
when you say check for wiring errors... i'm assuming you mean the polarity?
It is the Canary amps that use choke-input power supply filters. Your system should be just fine with both of them on a single circuit.
If you don't get the electrician back to install three dedicated circuits, then you can use the one on the opposite leg to power your computer or install a noise filter.
I thought of another question for you. We have been assuming your power amps use three-wire power cords and that the "ground" is connected to the chassis. However, it is possible that someone intelligent enough to use a choke-input filter would also use a two-wire power cord, or install an IEC connector where the "ground" is not connected inside the amp. Can you tell us whether your amps have the exposed metal connected to AC "ground?"
my lines travel along the outside wall of my condo, they don't travel near any appliances. the outlets are installed inside the drywall, using some type of metal box i'm assuming, with oyaide R1 outlets and nylon face plates. there are two circuits in one ganged box and the third on alone by itself. the two that are together are on different legs.
> > > > > > > > > > > > > > > > > > > > > > > > > > >When the electrician first came out to look at the job did you tell him you wanted three dedicated circuits? Very important you used the word "dedicated"...... and not the word "separate".......
Dedicated means a branch circuit with it's own dedicated hot conductor, neutral conductor, and equipment grounding conductor.
A separate circuit means its own hot conductor, but not necessary its own neutral or equipment grounding conductors.
As you have described, two circuits share the same 2 gang cut-in box. The two circuits are not fed from the same Line in the panel. One is fed from L1, the other L2.
My guess is the electrician installed a 3 wire + grd multi-wire branch circuit.
Two hot conductors,
One neutral conductor,
One equipment grounding conductor.
With this type of multi-wire branch circuit the 2 hot conductors share the same neutral conductor. The two separate circuits are required to be fed from the two separate Lines of the panel, L1 and L2. Not good for audio.On a 3 wire multi-wire branch circuit only the unbalanced load will return on the neutral. Example, if circuit #1 has a load of 5 amps, and circuit #2 has a load of 5 amps, then the unbalanced load of the 2 circuits is 0. That means no current will return on the neutral conductor to the source. It also means that both 5 amp loads are in series with one another.
Example 2. If one connected load is 5 amps and the other connected load is 3 amps, then the unbalanced load that will return on the neutral will be 2 amps. 3 amps of the load will still be in series of the two connected loads.
You can check if you have dedicated or separate circuits at the 2 gang installation. Turn off all three circuits. All three circuits? We do not know if the third circuit travels through this same 2 gang box.
* Pull the cover plate.
* Pull the two duplex forward from the box. Note if the wire is solid it will be stiff to say the least. If stranded it will pull out fairly easy.
* Look for the white conductors that attach to each duplex outlet. Do they joint, splice, to a common white coloured wire? If so this is a multi-wire branch circuit. If on the other hand if each white wire that connects to each duplex does not joint with a common white wire and instead enters from a raceway that enters, connects, to the box then the circuits are dedicated.Just an added note. A 3 wire multi-wire branch circuit will also have a shared equipment grounding conductor, You will see the green wired jointed in the same manner as the white neutral conductor.
Even if you indeed do have dedicated branch circuits unless the electrician insulated one of the duplex recepts supporting traps, from the metal 2 gang box, the two supporting straps are bonded together because of the metal 2 gang box. this is perfectly legal.
--------------So if you told the electrician you wanted dedicated branch circuits and he gave you 2 separate circuits in the 2 gang box then he should on his own time correct his error.
i'm almost 100% sure i have the multi-wire branch circuit. i said "dedicated", but then he showed me the 10g romex, showed me the one neutral/ground that would be shared, and i said "ok". so i dont think i can go back to him.
i need to try and find a way to live with it i think. i have two circuits that are on the same leg. can i use a balanced power unit on the third leg for my computer (i'm setting up computer based audio) and router without inducing hum?
if not, i'll just stick with the two outlets. the third one is useless to me, and honestly, with my stereo, maybe the two is enough. i dont have home theatre, i dont see my needs growing, and i need to try and keep costs down. i've already blown a lot on this project.
i'm almost 100% sure i have the multi-wire branch circuit. i said "dedicated", but then he showed me the 10g romex, showed me the one neutral/ground that would be shared, and i said "ok". so i dont think i can go back to him.
> > > > > > > > > > > > > > > > > > > > > >You said "Dedicated" obviously you did not get Dedicated. You are not an electrician you do not know exactly what wiring method is involved for a dedicated branch circuit. You do know that a dedicated branch circuit has its own dedicated Hot, Neutral, and Equipment grounding conductor.
Did you tell him you wanted the three dedicated circuits fed from the same, leg, or side, or LINE, of the electrical panel? He knows a multi-wire branch circuit can not be fed from the same Line.This guy charged you, I believe you said, $170.00 per hr. He represented himself as an electrician knowledgeable of audio equipment.
I would give him a call. I would tell him you get a ground loop hum when you use both circuits from the 2 gang outlet box. I would then say, "I asked you to install dedicated circuits?".... then pause allow him to answer...If he says, "That is what you have, that is what I wired".... Then ask him if that is what you have that means each dedicated circuit has its own dedicated hot conductor, neutral conductor, and equipment grounding conductor...... Wait for his response before you say anything else.To be honest with you, the guy probably is a good electrician. But he is not an Audio savvy electrician. No electrician with a background in Audio would install a multi-wire branch circuit, two 120V separate branch circuits.
For what he charged you, you could of looked in the Phone book Yellow pages and hired a NECA/IBEW electrical contractor for far less money. A contractor licensed, Bonded, and insured.Post back if you call the guy that did your electrical work. Let us know what he said.
If the DC in Steve's moniker means District of Columbia, then he would not be able to hire an NECA/IBEW electrical contractor for less than $170 and hour. I live in Arlington, VA and, coming from SC, am still pissed off every time I get a quote from a contractor of some type. Needless to say, I end up doing a lot of the work myself. The latest quote was to install a gas water heater (in a location 5 feet from the old one) for approximately $2,000. Give me a freakin' break!
Louis
If so, a lot of the cost is for standing around waiting for the inspector.
They wanted $800 to do some water piping that would have cost about $150 in Greenville, SC. Evidently there are a lot of people around here with a lot of money who pay such prices, because none of the contractors care whether they have your business or not--they are plenty busy without you.
I don't know how reliable the building inspector is in your area. We have a good setup here, where you can make an inspection appointment through an automated phone system. The inspector showed up right on time and signed off the job quickly.
If your contractor has to wait for a day or two for the inspector to show up, I can understand the high bid.
If they were building anything else into the price related to the inspection, then they didn't itemize it, and, in fact, made it to look like the fees specific to the work being done. Ultimately, some "waiting around" money could be built in, but nothing was said of it.
i'll call and talk to him. i've spent so much on this, the thought of spending more is not appealing at all. i went with a consumer rated electrician, not just anyone our of the yellow pages, i thought that would mean i get what i need. obviously not. i'm kind of upset by the whole thing. bit what's the big deal w/ just using the two lines and calling it a day? i mean, shouldn't i cut my losses here?
Steve As for the guy that wired your branch circuits I would not pay him another dime......... I contend he should know the difference between a dedicated and a separate circuit.As for the 3 wire multi-wire branch circuit you have now, if you only use one of the two circuits that would basically be a dedicated circuit. So you have two dedicated circuits. Just make sure the one you use is fed from the same Line as the single duplex dedicated circuit. As for the odd ball separate circuit.......see if the electrician that did the job will at least come to your home and either move the circuit in the electrical panel to the SAME breaker as the good circuit, or disconnect the oddball circuit from the breaker and at the 2 gang outlet box rework the two duplexes so they will be fed from the good circuit. This will give you a dedicated 4 plex.
As for connecting your computer to the other separate circuit imho you power amps will suffer, imo. Computers are filthy beasts when it comes to the junk they put back on the AC line. Remember on a 3 wire multi wire branch circuit only the unbalanced load will return on the neutral conductor to the source. That means the rest of junk on the current of the computer would be in series with the power supplies of your power amps. Kind of defeats the purpose of the new circuit don't it?
ok, i think i can get him back to move that separate but not dedicated circuit onto the same leg. is there a way he can fish a new ground wire for that separate circuit, to make a dedicated circuit?
as for the computer... not sure what to do here, i'm setting up a music server. where do i put this? outside of these separate/dedicated circuits?
sigh...
If you can plug it in to another circuit, that would be the best. If you have to use your spare circuit, isolate the computer with the best filter you can find.
You may also want to plug a damper such as the Quiet Lines unit into the spare circuit if you are going to use it, or switch its breaker off if you are not.
I have the CA160's myself, along with the CA903SE (4 box) preamp. Good stuff!
Louis
yes, i love the amps!! awesome! i think i'm just going to use the 2 dedicated circuits. the third isn't useful for me, maybe i just plug in some blue circle noise hounds on that extra outlet...
The power draw from the monoblocks is the cause of the hum. If you put two romex's side by side and power one..there will be a voltage induced between the grounds of the romex runs. This is what I believe you experienced.
If you have the electrician do anything, have him tie the grounds together at the outlets. That could be as simple as attaching the boxes if they are steel, or may require running a seperate wire. Note that I do not know if doing so is code, you need to ask the electrician. When he is there, have him connect the grounds, then you try the amps on two lines..if the problem is gone, voila.
Cheers, John
hmm, ok. the two monoblocks were on their own ciruit, but these two circuits are in the same ganged box, and are actually using the same ground wire. the 10g romex comes wrapped with two lines (hot) and one ground in the same run. does that make sense? could this be part of the problem?
And Ithought the electrician contractors that did my house were the scrimpenist chincers that ever pinched some pennies but man shared return lines......now that's low!
Obviously this was done to save a buck. Even if the installer doesn't really understand good grounding should use higher end materials just beacause you were paying him top dollar for a high end install.
Well it kinda makes me a little mad to think about it. Seperate not equal to dedicated, damn I guess I'll need my lawer present when I hire my electrician to make sure he doesn't have some shared ground loophole clause in our conbtract. Sheesh! What next?
lordy i feel bad about this purchase.
the upshot is that i do have two lines out of three that are dedicated, right? both on the same leg. i definitely have heard an improvement using these two lines only. improvement in imaging, and effortlessness of music.
As I've said elsewhere, your Canary amps have power supply designs that produce little or no electrical noise, so there would be no real advantage as far as noise goes in having each monoblock on a separate dedicated circuit. Most other power amps would benefit from separate dedicated circuits.
You will still benefit from damping your dedicated circuits. If you are not interested in DIY, Audioprism makes dampers called Quiet Lines. See the link.
how about a couple blue circle power pillows? same thing? i've already got one...
The information available on-line is sparse, but the limited description provided by Blue Circle suggests these are indeed R-C filters.
Try yours and see if you hear an improvement. Try it on both the active and alternative lines.
You have 2 separate circuits, not 2 dedicated circuits.
It is a 3wire multi-wire branch circuit......
Please detail a bit more. From your description, it sounds like he used a 10/3 cable. I've seen 12/3 in my house, and I installed a run of 8/3. Both have a ground wire, a neutral wire, and two hots..a red wire, a black, a white, and either green or copper ground.
If this is the case, then they are sharing a common neutral. If you put one amp on each hot leg, then there will be no neutral current.
If this is the hum cause, it will only get worse when the amps are being used, as the draw will be some glorious (hideous) combination of neutral currents and hot currents..
If you have him switch both legs to the same side of the service, then the neutral currents will be the sum of the two hots.
I'd have approached it the way Ted Smith's setup was done, wires in conduit with a honker ground run for the whole shebang (If I recall correctly). But you should ask him, as it's been a while since we discussed it.
Cheers, John
you said:
"wires in conduit with a honker ground run for the whole shebang "
I would worry about the conduit altering the power quality depending on the material. Other than that That seems like a pretty good idea but without knowing what honker really means I might be tempted to lay that honker in a broad piece of copper foil or woven sheath.
I'm sorry man but installing shared neutrals seems less than ideal too me from a line loss perspective no matter how honkin consideering it's likely easier to muscle more copper through in parallel than in one big unweildy conductor. Is this a RF noise reduction line of reasoning with this approach? I am very sensitive to line losses in my system and might even take a bit of RFI over extra line loss if forced to choose but I think if I could afford to design my ideal layout for these dedicated service runs I think I could even do it with parallel grounds while keeping RFI down by running them resonably tightly bundled.
HowdyNote that the big honking ground isn't a big honking neutral. My electrician used two #10's per circuit (with no splices from the breaker to my outlets) and a big honking shared safety ground wire from the box just outside my sound system to the main breaker box. Also he used two ground rods at each end of that big ground wire. When I brought this topology up in posts earlier the more knowledgeable about codes among us asked a lot of questions that I couldn't answer except that my electrician is a code freak himself so I'm comfortable that what he did was both in line with local and safe. So if there is a conflict it's more likely that I haven't described things well. I also know it sounds good and I don't have significant ground loop hell except for the separate satellite ground that I've handled separately. Also for what it's worth we have SWER power distribution ( http://en.wikipedia.org/wiki/SWER ) here, so lightning is much more of a theoretical problem in our whole neighborhood than my two (four) extra grounds :)
-Ted
Ahh! It all makes sense now, thanks for the explanation. For some reason I started thinking this shared neutral was an epidemic or something, and had begun to question my own sanity.
Re the shared earth: I think this might even be THE way to go for RFI immunity but I would assume the conduit is a code requirement for this type of installation. Does the code specify a conduit material/conductivity? If you could get away with using a conduit material that has minimal interaction with the signal itself then this way sounds nearly perfect to me. Obviously you will still have to be careful about starring out from the honkin earth at the equipment end of the run....but I like it.
Howdy
I know people are worried about the material in the conduit, but I wouldn't stress about it. The difference from standard wiring to dedicated lines is sooo big in my experience that I'm skeptical about the additional gains to be had with other conduits. I suspect that the specs are more about robustness when nails are accidentally driven into it, etc. than conductivity... But perhaps the conductivity is part of code too, that's why I hire an electrician :)
-Ted
Howdy Ted,
I kind of geek out on things sometimes, so I'll understand if you get bored and quit replying :)
In the end I would definitely approach a licensed pro to get the job done, but I also expect I'll have some design already either written down or in my head that I would expect the installer to closely follow while offering advice on how to pull it into code conforming configuration.
I really like the single ground idea and I bet it sounds really good that way too. I think the only way that's gonna approach satisfying code around here where I live is with conduit. If I could get away with PVC for the conduit material or somthing easily accessible like that I think that would satisfy my needs. Do you happen to know what your conduit material is? I suspect most are metallic and grounded but I'm sure no electrician.
Regarding the questionable signifigance of this particular detail: the skeptic in me always doubts and is stingy with the money but the eccentric audiophile says nothing is too good for my precious. Those two are constantly going at it.
I have a nagging voce telling me maybe there is a concern under the right conditions. I think what would worry me most is high current lines. I know my (class AB) amps don't have any real regulation on the final stages rails and so will be fairly susceptible to line noise and I'd rather avoid power conditioning and filtering as much as possible.
Bear with me I came up with a hybrid solution for the forums consideration. I think this hybrid approach could allow for taking advantage of the benefits of your approach but avoid ptential power quality pitfalls where they are expected to be a concern. For example I like your solution for low power devices with very little ac line current demand because low power devices, ie low ac current draw devices, should minimize this potential coupling between ferrous conduit and service conductors current and you still get the added RF immunity a single honkin ground offers. Then for higher powered devices like monoblock solid state amps for example you could run another set of dedicated lines that are all independent, ie no conduit, and have their own ground lines etc since these are the devices which might be more apt to have strong coupling with surrounding conduits, wires, environment, etc. By seperating out the high current lines this way would allow them to be routed at a slight distance to reduce the inductive coupling.
I would never let something like this slow me down from getting dedicated lines. I have an audio tweak budget regeneration cycle going right now which pushes a luxury item like dedicated lines out a while so I have time to think about the possibilities. Maybe your're right and this is all worrying for no reason but at least I'll have thrown my idea out here on this forum for critique. It always surprises the great answers I get by discussing on AA here. You all have a great thing going with this website.
Separate dedicated circuits are the way to go. If you can avoid conduit, I think that would be best. Conduit is available in steel, aluminum, and PVC. Steel would have nonlinear magnetic interaction with the power current. Aluminum would avoid the magnetic interaction, but would increase capacitance of line- and neutral-to-ground. It would also have acoustic ringing problems. PVC should be the most neutral of the choices, but would still introduce some sonic vibation behavior. If you have to have conduit, try to wrap the stuff with rubber tape after the inspector has blessed it.
Cheap house wire cable is insulated with PVC. Oyaide makes polyolefin-insulated, carbon-damped cable, but it is very expensive. If nothing is too good for precious, I would look into this stuff.
With me being involved as an ameteur AM radio station operator/ local wireless and wired network administrator (of my home)/ member of a high techish suburban community/ near bustling commercial and military communications and navigations signal hubs my audio equipment in is in the middle of what might very well be considered RF hell. I see the single ground wire, dedicated lines bundle, in conduit, in-wall, service run as a great weapon against RF and significant reducer of the length of the "necessary" ground loops a seperate dedicated lines suffers from and can't seem to let go of this thing. The problem is as I understand it, the only way to pull off this holy grail desired feature of a single ground there has to be a conduit in order to satisfy code. It is safe to assume that if I didn't use the lowest electrical impact PVC conduit material that the conduit approach is no longer an option and my dreams of this single ground wire system go poof in a wisp of smoke.
Obviously PVC isn't a perfect dielectric material so I understand your comment about how it may still be an imperfect solution signal integrity wise. My gut feel is that is less of an issue in my environement than RF immunity is. I don't see a way around that barring finding some more electrically inert conduit material. The other problem with this approach that you mentioned, vibration problems, can be dealt with almost entirely. I can as you point out mechanically damp the conduit if necessary. Maybe some of that expando foam insulation stuff in the wall surrounding a rubber tape wrapped bundle might keep it all holding still.
There are also imperfections in the seperate dedicated line approach. It introduces longer parallel lengths of ground conductor. This means more potential for noise energy to be injected into the signal vs the single wire approach via crosstalk and radio signal reception. To battle the RFI problem the bundle can be more tightly packed. However the tighter packed bundle would have the tradeoff of being more likely to have crosstalk issues. To battle crosstalk issues the bundle may be more loosly packed but that means a tradeoff in RF immunity performance.
What confuses me about your post is it's tough to tell exactly why you prefer a seperate set of dedicated lines over a bundle in PVC that has one low impedance ground wire. The question is: are the noise/signal distortions tradeoffs for the conduit approach worse than the noise/signal distortions tradeoffs for the seperate dedicated lines outside conduit approach you are recommending, and under what conditions is it true? I guess my big problem here Al is my little voice inside is contradicting what you are saying slightly. This worries me a little because your obviously an intelligent and thoughtful fellow. This is a general topic which is difficult to talk about in specifics since everyones situation is different.
I like separate circuit cables because of the hot and neutral isolation they provide. In an environment like yours, a single ground wire would be preferred. It is acceptable per code, as I understand it (disclaimer: I am not a licensed electrician), to tie the separate ground wires together at the audio system. This would almost be as good as a single wire. Almost, because the individual loops between the audio system and the breaker panel can still support resonance modes. The difficulty is finding an electrician who will install exactly what you want, and not try to talk you into a subpanel. A subpanel, even if fed with heavy wire, defeats the isolation afforded by separate dedicated circuits with cables back to the main panel.
A metal conduit must be grounded, and makes a second ground circuit from the breaker panel to the outlet box. A metal outlet box will tie this circuit to the ground wire if you use any audiophile outlet I'm familiar with. Nylon screws and washers to mount the outlets would break the outlet-box connection. I'd prefer a plastic box, but I don't know if such are allowed with metal conduit.
Thanks for replying. That clears things up nicely.
Howdy
I do understand in principle about tweaking every last little bit out.
On PVC I think you'll find those that don't like the sound of it as a dielectric... I wouldn't have a guess what they would feel about using PVC vs. a conductor for power conduits :)
I too have amps which can draw a lot of current: SimAudio Moon W-10 monoblocks each on their own dedicated circuit. Tho they only draw 48 watts at idle they can draw quite a bit since they are happy doing 2200 watts into 2 ohms. I'm sure I never push them anywhere near that hard but their instantaneous current draw can be large.
I have another similar compromise in my system. I have conduits embedded in the concrete floor for the left rear speaker, right rear speaker and to the sweet spot for my transport. (See my room renovation pictures: http://gallery.audioasylum.com/cgi/view.mpl?UserImages=7184&invite=194917041 ) I really wanted to get ceramic pipe for this purpose, but unlike years ago, there isn't much ceramic piping to be had these days. I gave up and put in PVC and chose a speaker wire for the rears which already has air dielectric, etc. (AudioQuest Mont Blanc) and power cords with thicker casing (Shunyata Taipan Alpha Helix.) I don't think I'm hurting too bad :)
-Ted
Hurting? I wouldn't say that! In fact that's one of the coolest looking piles of stuff I've ever seen. I wouldn't even have to be there to assume it sounds amazing.
It's kinda funny, your pictures remind me of my own system. It is more like the redneck, poor man version of the same thing, with mine still very much being a work in progress. We have a similar design approach in the full range speakers and the big amps to drive them, but yours likely cost wwwaaaaayyyy more. Judging by the looks of it yours is one of few of a rare few Asylum systems I've seen that I'd be nervous about putting mine against in a raw SPL competition and yours obviously has an extra level (or two) of refinement in quality mine will never touch. I'm going to try and email you a photo of it this week even though I don't have it posted in inmates systems because I think you'll get akick out of it and maybe even a bit of a laugh. For example where you have a giant wooden shelf in back holding a whole bunch of equipment, in my system in that spot you'll find a full height industrial computer server rack full of my amplifiers computer and various other rack mount gear. Redneck I tell you.
My amps are mid eghties JBL/Urei model 6290's with quieted Pabst fans replacing the stock fans for nearly silent operation. They can draw some current as well when set free (my house wiring really needs an upgrade) as they are rated at 1200W into 8 ohms as I have the fronts configured (bridged). These amps are in fact pro amps I got from Morgan sound in N. Seattle area when they were upgrading to digital. At $50 each I think I scored a fine deal, the owner was a bit tweaked when she found out what the sales guy was giving them to me for. At that price I told hime give me four and I already have more into tweaking them than I paid for them haha. The main problem with them seems to be the fans they come stock with but I solved that. Other than the fans they are dead quiet, sound great to my ears, and pack a big punch. I can't wait to try them on some dedicated lines.
HowdyWell here is old older picture of my old house:
Here's my office before that:
I thought you were in the Seattle area, but I guess I'm mistaken. If you come to the neighborhood you'll have to drop by and visa versa.
-Ted
I'm down here on the South end in Des Moines actually.
It's good to learn I'm not alone up here. Regular folks just don't seem to understand.
Drop me a line sometime when your bored we could shoot the breeze. I've always wanted to hear a higher end system designed for full range and have someone critique what I'm running as well.
Steve,
Glad to hear (pun intended) the ground loop is gone. If I understood the discussion correctly, switching the legs on the breaker for the third circuit is not likely to cure a ground loop--it is for other (EMF, RFI?)noise isolation.
It doesn't sound like you need to check polarity, given that things are fine. But, you may want to purchase a polarity tester from Home Depot or a hardware store the next time you're in one. They are cheap, easy to use (you just plug them in like any other plug), and good to have around. They can also tell you if you have an open ground, for example. Get the kind with the GFCI tester, so that you can test your GFCI circuits.
Louis
ok, will do.
not sure tho why i dont want that third circuit on the same leg, isn't that the reason i had the ground loop in the first place? which was solved by moving my equipment onto the outlets on the same leg?
All I can do is quote what Al said below:
"Connecting your audio system to outlets wired to both AC legs increases its exposure to RF noise and degrades the purity of the sound, but, if all the neutral wires are installed correctly, you should not experience any audible hum. Something else appears to be wrong."
The fact that the third circuit is on a different leg, all else equal, should not have been the cause of your ground loop.
If it makes you feel better, then have the electrician come back out and switch the third breaker to the other side. He/She won't do it for free, nor should he/she be expected to, unless you originally requested that all three breakers be on the same AC leg. Specifiying dedicated lines does not necessarily imply that they all be on the same leg.
does that mean the electrician didn't install the lines correctly? if not, i'll go back to the drawing board on my end. it's a shame that third line is just going to sit there, unused...
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