[Dalsegno]

I installed a dedicated line for my audio rig when I renovated my apartment, purchased fancy Furutech outlets and covers and still have a bit of 60 cycle hum from woofer and buzz from tweeter.  It is inaudible until you put your ear within a foot of the speaker.  I turned on system with a digital source selected.  For frame of reference, I never turn my volume past 12 o'clock (actually usual listening levels are 9-10 o'clock for very satisfying volume to me.  Amp is Line Magnetic LM 518IA (tubes), digital is Bluesound Vault 2 into Mytec Brooklyn, Speakers are Merlin VSM-MM w/Super BAM.

Here's what I measured:

Background sound level in apartment: 29-32db

Sound level at listening seat: 31db
Sound level at 1' from speaker:34 (amp volume off): 32-33db
Buzz at tweeter: 45db (amp volume off)
Hum at woofer: 47db (amp volume off)

Sound level at listening seat: 31db
Sound level at 1' from speaker: 34db (amp volume at 12 o'clock)
Buzz at tweeter: 51db (amp volume at 12 o'clock)
Hum at woofer: 48db (amp volume at 12 o'clock)

My a/v guy who only works on my den surround system took a listen and thought the noise was pretty negligible and might just be normal order of things, and he is a recording musician and sensitive to noise, and he understands just knowing the noise is there can impact our psyches.  I guess I need a reality check as to whether my system is "noisy," and if so, what power conditioning might be able to do for me.

Thanks in advance.

DS

[FullRangeMan]

60Hz noise on the woofers and hiss at the tweeter is not good or acceptable, seems there is polluted land lines in you building/condo or AC interference in your apto from other equip as air cond, water boiler etc.
IMO

[WGH]

An audio buddy has the Line Magnetic 218ia in a very small room. Over the years I have listened to the amp with at least three different pairs of speakers and have never heard a tweeter buzz.

I had a low level tweeter buzz which was a bear to track down. The culprit turned out to be a computer monitor that was used with my music server, the noise was persistent whether the monitor was on or off, it was only found by systematically unplugging everything.

While tracking down the noise I bought a Viborg power cable based on enthusiastic reviews by guys in our audio club. The noise remained but my system had a little more bass and fullness over the stock 16 guage power cord and since the cable is shielded I no longer had to be concerned with 60 Hz noise leaking into components.
https://www.audiocircle.com/index.php?topic=181947.msg1911603#msg1911603

[nlitworld]

There could be a few things causing that hum. First off, there's always possible DC on your AC, even with a dedicated circuit. Perhaps some dimmer switches located around your house causing you trouble? Do you have any power conditioning/filters going on already? For me, a PSAudio filter and IFi plug in power filter really helped. Secondly, could you simply have some signal cables too close to power cables? Perhaps some rca cables near power cables? For my amp, I MUST keep the rca min 6" from power cable or it gets real noisy. Cables closer to the source makes the hum exponentially louder too. Lastly, is it possible the hum is internal to the amp and now your system is quiet enough elsewhere to make this more noticable? You'd be surprised the effect of unshielded internal signal wires a little too close to power supply inside the amp.
I always felt like Michael McKean's character in Better Call Saul when trying to find the source of hum around the house.

Tracking down hum is a real P.I.T.A, but the end result is SO worth it. Good luck in your search!

-Lloyd

[Early B.]

Your AV guy is right -- you don't have a noise problem.

[Dalsegno]

60Hz noise on the woofers and hiss at the tweeter is not good or acceptable, seems there is polluted land lines in you building/condo or AC interference in your apto from other equip as air cond, water boiler etc.
IMO

Could very well be the case.  Any thoughts on a power conditioner that could help?

[Dalsegno]

I had a low level tweeter buzz which was a bear to track down. The culprit turned out to be a computer monitor that was used with my music server, the noise was persistent whether the monitor was on or off, it was only found by systematically unplugging everything.
https://www.audiocircle.com/index.php?topic=181947.msg1911603#msg1911603

That's a great idea. I'm going to unplug everything and then plug them back in one at a time to try to trace the noise.

[Dalsegno]

There could be a few things causing that hum. First off, there's always possible DC on your AC, even with a dedicated circuit. Perhaps some dimmer switches located around your house causing you trouble? Do you have any power conditioning/filters going on already? For me, a PSAudio filter and IFi plug in power filter really helped. Secondly, could you simply have some signal cables too close to power cables? Perhaps some rca cables near power cables? For my amp, I MUST keep the rca min 6" from power cable or it gets real noisy. Cables closer to the source makes the hum exponentially louder too. Lastly, is it possible the hum is internal to the amp and now your system is quiet enough elsewhere to make this more noticable? You'd be surprised the effect of unshielded internal signal wires a little too close to power supply inside the amp.
I always felt like Michael McKean's character in Better Call Saul when trying to find the source of hum around the house.

Tracking down hum is a real P.I.T.A, but the end result is SO worth it. Good luck in your search!

-Lloyd

Thanks for suggestions and love the Better Call Saul reference.  I'm really hoping the cable dressing isn't the issue because i have a rather cramped space for my components and there aren't too many alternatives to keep signal cable away from power cable.  The thing is, I had the same cramped space at the last apartment, and a worse rats nest of cables than I do now, but there was no hum.  I keep wondering if a mover banged my amp during the move and that created the hum somehow, so having a tech go over the amp is definitely a possibility.

[nlitworld]

Look for a PSAudio Humbuster iii or an Van Alstine HumDinger for decent small and cost effective solutions to test the theory of DC contamination.

[FullRangeMan]

Could very well be the case.  Any thoughts on a power conditioner that could help?

Along the PSAudio Humbuster and Van Alstine HumDinger already mentioned, there is the inexpensive small filter PSAudio Noise Harvester to remove noises, I dont believe in conditioners, they need to be huge.
https://www.psaudio.com/products/noise-harvester

and still have a bit of 60 cycle hum from woofer and buzz from tweeter.
When these noises started to appear?

[Rusty Jefferson]

.... Amp is Line Magnetic LM 518IA (tubes), digital is Bluesound Vault 2 into Mytec Brooklyn, Speakers are Merlin VSM-MM w/Super BAM....

Having the system as quiet as possible can definitely improve the listening experience. Those speakers are only 88-89db efficient even though Merlin stated higher. If your speakers were actually 95dB efficient you'd hear that noise from next door. Before making any changes to the electrical path have you ruled out equipment noise? Assuming you're using the Mytec as a dac/preamp straight to the amplifier. Have you tried a different amplifier yet, preferably one known to be very low noise and not a transformer coupled tube amplifier? Not as a permanent replacement but just to listen to the noise level.

[Big Red Machine]

I had a similar tweeter issue several years ago. It was very nagging. That disappeared once I went with fully balanced gear dac to pre to amp, AND used high quality power cables from Synergistic and others. Even though I had a Puritan conditioner in place, it could not eliminate what the single ended devices were souring the lines with. Today, the system is black and sound jumps out at you. Unfortunately there is no one single solution to this issue. You have to build the SYSTEM.

Happy listening.
https://www.audiogon.com/systems/10635

[toocool4]

I take it this Line magnetic amp is an integrated amp, if so turn off and unplug everything you have plugged in to it.
Then just have the amp connected to the speakers, switch on then test again by turning your volume up. If you hear the same noise still then it’s your amp, if you don’t hear any noise then start putting the sources back in one by one till you find what’s creating the noise.

[Tyson]

Stuff like this is the reason I ended up going with a Bent Audio preamp using autoformers. 

[Early B.]

Stuff like this is the reason I ended up going with a Bent Audio preamp using autoformers.

Yeah, I have all tube gear (amp, preamp, & DAC with a total of 15 tubes), and every time I power up the system, I wonder how much tube noise I'm gonna get. It comes with the territory just like pops with vinyl. When guys with a bunch of tube gear say, "My system is dead quiet," that's probably not entirely accurate.   

[Tyson]

Yeah, I have all tube gear (amp, preamp, & DAC with a total of 15 tubes), and every time I power up the system, I wonder how much tube noise I'm gonna get. It comes with the territory just like pops with vinyl. When guys with a bunch of tube gear say, "My system is dead quiet," that's probably not entirely accurate.   

I make up for my lack of a tubed preamp by using a tubed DAC and tubed amps, haha!

[Dalsegno]

Well here's a happy and somewhat embarrassing tale-- I hadn't adjusted the amp's "Hum Balancer" pot in a really long time.  It just took a couple twists of a screwdriver only in the right channel to eliminate all hum for both channels.  It was kinda magic.  Of course now I'm left with the tweeter buzz.  I'm going to unplug everything and see if that eliminates the buzz. 

The guys that sold me the furutech outlets were trying to sell me a Synergistic PowerCell and I could probably use some extra outlets.  Any thoughts on adding one of those?  *ducks*

[Dalsegno]

Yeah, I have all tube gear (amp, preamp, & DAC with a total of 15 tubes), and every time I power up the system, I wonder how much tube noise I'm gonna get. It comes with the territory just like pops with vinyl. When guys with a bunch of tube gear say, "My system is dead quiet," that's probably not entirely accurate.

Yeah I'm afraid I'm just a tube guy too.  I was a guitar player for a while before remembering I'm much better at piano, and maybe I spent enough time playing a strat through a blackface Super Reverb that I just expect my gear to buzz?  Hope I can ameliorate this buzz a bit now that the hum balancer adjustment has worked some magic.

[Dalsegno]

While tracking down the noise I bought a Viborg power cable based on enthusiastic reviews by guys in our audio club. The noise remained but my system had a little more bass and fullness over the stock 16 guage power cord and since the cable is shielded I no longer had to be concerned with 60 Hz noise leaking into components.
https://www.audiocircle.com/index.php?topic=181947.msg1911603#msg1911603

Just ordered from Amazon.  Thanks!

[cementhead]

Dalsegno, I have a S.R Power Cell. I still have a slight noise from the system, which does not increase with volume, so I am not too worried about it. I gave up on trying for a complete black background, as some days it is noisier than others. I cannot hear any hum from the listening chair.