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Power supply hum transmitted to loudspeakers

I know the issue of hum and buzz has been discussed endlessly. Is it not almost universal that all amplifiers with power transformers have some low level power supply noise that will cause minimal leakage hum, buzz, or hiss through the loudspeaker with your ear close enough and no inputs to the amp connected?
Is this considered the noise floor of the amplifier? According to Galen Carol's website, if you can't hear it through the music and your system sounds the way you want it to, this idle noise should be ignored. Any thoughts?


normie57
gdhal's avatar
gdhal
1,641 posts
 
@normie57

if its a "hum", try this https://emotiva.com/products/accessories/cmx-2


almarg's avatar
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almarg
9,670 posts
 
I agree with Cleeds. To make a meaningful test of an amplifier's intrinsic noise level shorting plugs should be connected to its inputs.

Many choices of RCA shorting plugs can be found at eBay, by entering "RCA shorting plugs" into its search box.

Regards,
-- Al
boxer12
8,656 posts
 
I run high efficiency Lowther speakers. They pick up everything. FWIW... What has helped my system is running everything except the mono amps through an Exact Power SP15 transformer. Also, I've found that I need to keep the SUT away from the other electronics. Well shielded  interconnects & power chords are also a must. 
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audiobrian
184 posts
 
I believe most amplifiers/systems have some very minimal noise audible through the loudspeakers at idle. Some have background AC, ceiling fans, pool pumps etc which make this noise floor less or perceptibly inaudible.  I own some Clayton monoblocks which I love, have had their power supply upgraded, but still has a small amount of buzz at the loudspeakers, not audible while playing music beautifully.(with and without shorting plugs). I've learned to ignore it and realize the amplifier was meant to play music, not to necessarily be dead silent at idle.
Good luck!

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