Electrician specializing in audio needed Buffalo

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?

Romex?

MC cable?

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.

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.

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.

Phone: 716-662-6111
.
Jim

Jim,

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.

Tmmvinyl,

Thank you for responding back to my post.

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.
07-18-15: Tmmvinyl

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.

Jim.

Thanks again Jim. Does lifting the ground on my power amplifiers do anything to degrade the amp's sonic capabilities?

Does lifting the ground on my power amplifiers do anything to degrade the amp's sonic capabilities?
07-19-15: Tmmvinyl

Tmmvinyl,

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.

Jim