Transformers humimg........again

You can install a balanced power transformer outside by your electrical panel to feed the 20A dedicated line. Although not to code (JEA48 can fill you in on the details ) it will cure the problem.

For more details on balanced power look up Bryson's Tourous products and Equitech they offer sub panels with balanced power transformers.

Good listening

Peter

You can minimize the effects of transformer hum by isolating the transformer from the chassis and from the circuit boards. Remove or loosen the bolt(s) holding the transformer to the chassis and place 1/8" cork under the transformers. That should help.

Emotiva CMX-2

Pbnaudio,

The BPT 3.5 Signature ac isolator is a balanced power transformer unit. It is good for 2400Va / 20 amps FLA at 120V.
http://www.6moons.com/audioreviews/bpt2/flagship.html

>>>>>>>>>>>>>

Shawnlh,

Now the important part, ALL components that utilize a transformer (BPT, Naim, REL's) all have transformer hum. And yes, it is transformer hum, NOT sound from the speakers.
Shawnlh

First off all transformers hum to some degree, some more than others, that is normal. Now if you can hear them while seated in your listening chair that is not normal.

Tried many other outlets in the house, with and without the BPT unit. No difference, all transformers still humming, whether alone or not.

Jmho that rules out DC on the mains. Had you said with a piece of equipment plugged into the BPT the transformer of the piece was quieter but the BPT was noisy, then I could have considered DC on the mains as a possibility. An isolation transformer will not pass DC from the primary winding to the secondary winding. A piece of audio equipment plugged into the BPT output would not be affected by DC on the mains feeding the primary winding of the BPT toroid transformer.

I see you live in Canada. I believe your generating and distribution power system is the same as here in the US.

Just a few things your electrician friend should check. Have him check the mains voltage at the main service electrical panel. Make sure the voltage is the normal voltage for your area.. Have him check hot L1 to hot L2.

Then check hot L1 to neutral, and then hot L2 to neutral. The two readings should be within a couple of volts of one another.
The combined voltage of L1 to neutral + L2 to neutral should equal the L1 to L2 voltage reading.

Next thing he needs to check is the Hz. It should be 60Hz possibly 59Hz.

Next have him check the voltage at the receptacle the audio equipment plugs into unload, nothing powered up, then check the voltage again with everything powered up. The voltage should not vary more than a couple volts.

As for an overhead electrical service, there is nothing wrong with them imo.

I assume the service feeding your home is single phase 120/240V nominal.

Post back your findings
.

Thanks Pbnaudio, your reply is copied, pasted, and printed. I will have electrician buddy check these points. I will report back.

Thanks muchly :)