There must be some Local 41 guys looking for some extra cash from side jobs; do you see anything in the buffalo evening news or any of the bee magazines (Amherst,clarence,etc...) Maybe the guys at the speaker shop on main street can give you some contact names to try.
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I have spoken with a number of electricians but none of whom have any real audio-specific experience.You really don't need an electrician that is audio savvy.
You just need to do your homework and write up a set of specs you want him to follow. The electrician will look at the specs then he will tell you what he can do and cannot do to meet code in the state and city you live in.
The electricians in your area will know the local codes for your area.
Example, he may not be able to use/install NM-B sheathed cable, (Romex is a trade name for NM-B), by code in your area for branch circuit wiring. The wiring may have to be installed in metallic conduit. If that is the case ask him if aluminum armor MC cable meets code. If so have him use AL armor MC cable with solid core conductors. Three wire, hot, neutral, and green insulated equipment ground. One MC cable for each dedicated branch circuit you want.
Avoid pulling branch circuit wiring in an empty installed conduit. Avoid installing a dedicated branch in a conduit with other branch circuits.
Pay close attention to pages 31 through 36
An Overview of Audio System
Grounding and Interfacing
If you are wanting more than one dedicated circuit spec all circuits to be fed from the same Line, leg, in the electrical panel. All from Line 1 or all from Line 2, but not from both.
Jim, thank you for responding.
I have two separately metered services into my home. One service is solely dedicated to my listening room. The panel sits directly beneath my listening room. I have 5 dedicated runs of solid 10 AWG wire from 20 amp breakers to 5 in-floor Furutech duplex outlets. The longest run of wire is 11 feet. All wiring is fully exposed and none of it travels through the wall. Getting this work done, required three different electricians, not one of whom had any interest in listening to me or in following my instructions. I am now looking for someone who can properly ground my installation because I am still dealing with a fair bit of hum.
For a test did you ever try connecting all the audio equipment to just one dedicated circuit's duplex receptacle and check for the hum you are hearing? You might want to try that first.
5 separate runs of what type of #10 wiring?
Conduit/s with #10 wires pulled in the conduit/s?
Hopefully you can see 5 individual home runs, one for each dedicated 120V circuit.
Are all 5 circuits connected to same Line, leg, in the electrical panel?
Best way to check is with a multimeter and measure for voltage from one duplex receptacle to one of the other duplex receptacles. Insert one test lead probe in the hot contact, small blade slot, of one of the receptacles of a duplex and the other test lead probe in the hot contact of one of the other duplex receptacles. You should read zero volts. Repeat the process from the first duplex receptacle to the remaining three. If you measure 240Vac nominal on any of the 5 circuits they are not all fed from the same line in the electrical panel.
If you do not have a volt meter you can try this. Go to the electrical panel where the 5 circuits are fed from.
I assume the electrical service is 120/240V single phase.
Check the panel circuit breaker numbers.
L1 > 1 .... 2 < L1
L2 > 3 .... 4 < L2
L1 > 5 .... 6 < L1
L2 > 7 .... 8 < L2
L1 > 9 ... 10 < L1
L2 > 11 .. 12 < L2
The 5 circuits should all be fed from L1, or, all fed from L2. They should not be fed from both.
Wow, an electrician/s that don't listen to the person that hired them and is paying them.
You need to find an electrical contractor that will work with you. With that said he has to follow electrical codes for Buffalo.
You might try giving the IBEW Electrical workers Local 41 a call and ask to speak with the Business manager or his assistant manager. Explain to him your problem and ask him if he can recommend an electrical contactor that will work with you instead of the other way around.
Thank you for all of your help.
I used three dedicated runs of Oyaide solid core 10 AWG wire from three separate breakers in the panel to three separate outlets dedicated to my power amplifiers and my direct drive turntable. Each run is fully visible from the panel to the outlet. The cable was not run inside conduit because the City inspector did not require it. I used two dedicated runs of Cardas solid core 10 AWG wire to two separate outlets dedicated to the power supplies for my phono stage and line stage preamplifiers. These two runs are also fully visible from the panel to the outlets and were not run through conduit.
I had previously checked the outlets with my voltmeter when first installed and found zero volts when checking outlet to outlet.So I had assumed everything had been properly run off of the same leg.
My mono power amplifiers have a ground lift switch. When I flip the switch, my system is dead quiet. I just don't like the idea of having to defeat ground to achieve silence. This seems dangerous to me.
Thanks again for your time.
Thank you for responding back to my post.
You have found and solved your apparent ground loop hum problem.It is not caused by the AC grounded branch circuits wiring feeding the amps. The type of branch circuit wiring that was used and the very short distances, lengths, of the runs rules out the chance the ground loop hum is being caused by the branch circuit wiring, imo.
The problem lies with the mono amps. If Ralph from Atmasphere
is following this thread he is more qualified to give you the answer why.
It's a good thing the manufacture of the mono amps incorporated the ground lift switch on the amps. The switch does not lift the safety equipment ground chassis connection from the safety equipment grounding conductor of the AC power cord, That would be dangerous and UL would not give their blessing and safety approve, List, the amps. The ground lift switch lifts the signal ground, B- DC power rail, from the metal chassis of the amp,thus breaking the ground loop circuit/s that is causing the hum.
So the bottom line is, it safe to lift the signal ground from the chassis/safety equipment ground.
JMHO no. You could contact the designer/manufacture of the amps for their opinion.
Now if for some reason an amplifier's electrical safety equipment grounding conductor electrical continuity connection to the neutral/ground bar was open then the floating above ground chassis would, I would think, act as an antenna and could cause RFI problems.
Again if Ralf, (Atmasphere), is following this thread of yours he could better address your concerns.
I would be willing to bet Al, (Almarg), could as well.
Thanks for the nice words, gentlemen.
As is usually the case, I agree with everything Jim has said. Including the fact that the ground lift switch can be presumed to not interrupt the connection between chassis and AC safety ground. In contrast to using a 3-prong to 2-prong cheater plug to defeat the AC safety ground connection, which is sometimes done to resolve ground loop problems despite the safety risk.
07-19-15: TmmvinylAs Jim suggested, it would probably be worthwhile asking Mr. Blume. (I assume, btw, that you are referring to your Coincident Dragon amps, as I don't think the Franks have a ground lift switch, based on their description at the Coincident website).
There are many conceivable effects that can depend on the position of that switch, and most of those effects tend to be system dependent and to generally have little predictability. But keep in mind that if setting that switch to the "lift" position resolved the hum problem, it may also have resolved other adverse sonic effects related to the ground loop that was present. Even effects occurring at frequencies that are themselves too high to be audible, but that may have had audible consequences by intermodulating with audible frequencies in the audio signal.
Also, an experiment that may provide added confidence would be to disconnect the input cable from each of the amps (leaving the speakers connected!), and using a multimeter to measure the AC voltage, if any, between the ground sleeve of the RCA input connector and chassis, on each amp. That would provide an indication of how far the circuit ground of the amp "floats" from chassis, when the switch is in the "lift" position. If the reading is small, say just a volt or two, it would provide added confidence in using that switch position. Have the amp turned off, of course, when you disconnect the input cable, and then turn it back on for the measurement.
And BTW, in the absence of specific information to the contrary I would not change the position of that switch while the amp is powered up, or within the first few seconds after turning it off.
Al thanks for your input. I am actually referring to my Frankensteins. The very latest incarnation of the Frankensteins have a ground lift switch. This afternoon I discovered that the source of the problem may actually be an inexpensive CD player (with a captive two prong AC cable) that I have been using to break in a new modification done to the Frankensteins. When I switched from the CD player back to my turntable, the hum was gone and no need to lift the ground; the hum returned as soon as I reconnected the CD player.
I will conduct the experiment you suggested at some point this coming week and report my findings here.