Reducing Humming Sound

I would say first, see if you can damp it by holding a panel firmly, if so, mass is your friend. :)

If the hum is the unit itself physically vibrating that is due to DC offset. The tricky but free fix is to figure out what else is plugged in elsewhere that is causing it. Its tricky because people sometimes find out by accident, other times after a lot of trial and error, and sometimes they never do find the cause. The other fix is a DC offset eliminator, and there are several, and they are pretty cheap as these things go, and not worth paying more so buy the cheap one.

My system makes all kinds of noises just like this. If I went around trying to eliminate every noise that could be heard faintly in a quiet room but not at all with music I would probably have wasted so much time and money there's no way I would have the (otherwise) best sounding system on agon. But to each his own. Know thyself. To thine own self be true. Etc. Etc, et cetera.

Now wait a dag-nab minute here! I happen to have the best sounding system on A'gon. :-)

Frank

Woah boys.

We all know the best sounding system in all of Agon land belongs to GK.
😇😇

But seriously.
This has a lot of positive reviews although not the cheapest for sure.

https://emotiva.com/products/cmx-2

I have one and it works as advertised....

If you’re going to use my word whoa could you at least spell it right? 

Depends what side of the Atlantic you hail from GK......


But yes whoa is the correct Merriam Webster dictionary speeling.

Us common peasants have slanged it to woah.

So sorry......

I'm not trying to be insulting or anything, we all don't know everything and it's ok to be wrong or not understand something. This is more out of concern for your safety and the fact you are asking the question you are.

DO NOT place any material inside the unit. You can and likely will start an electrical fire. More importantly, unless you have training and strong knowledge, you should not even open the unit and touch anything. Some electrical devices can hold a deadly charge even if unplugged for many hours. As an example, look up CRT tube anodes.

When in doubt about potentially dangerous things, whether it's risk to the equipment or especially yourself, find a professional. Being humble is better than being dead.

A device similar to the Emotiva is made in Minnesota by Audio by Van Alstine. I have three of them. I may or may not have the best sounding system on Audiogon, but I’m pretty sure I have one of the quietest rooms, and I do not like hum that I can hear during quiet parts of the music.

I have 3 2400 tripp lite, they all make noise. Yup, open one up you can get bit pretty good.  I was thinking an enclosures outside the room for me.

I haven't quite figured out what to do yet either. I do notice it.  Those thing are a bit noisy though.. I wonder if a variac would quiet them down. You know a volt or two on the input side, up or down.? Just a thought..
Second, mine you can push down pretty hard on the case and they do quiet down a bit..Bag of lead shot, stand on it, tough to get in a listening position with one foot on each conditioner, what about the third one, I don't want to go there..LOL

Regards

Thanks all for your suggestions!

I had always been a little bit leary about opening up this unit due to well, the possibility of death, but thought there might be an instance of someone who actually did what is was suggesting. I’m glad I asked before jumping in!

I will try dampening, externally, the unit in some way. Like I said, the hum isn’t particularly loud, so if I can apply some weight/pressure effectively, it should help a lot. I will also look at that Emotiva unit...it’s not that expensive, very doable. 
Thanks again and hope you are all doing well!

Arvin

P.S. I had a TrippLite unit about 15 years ago. I got rid of it because it hummed. Looks like nothing has changed.

Coils and especially large transformers will hum.  Some equipment is damped and isolated much better than others.  This is why well designed, well made transformers are extremely expensive.

I have had several conditioners that hummed loudly and in every case, it was the transformers.  Had to get rid of them.

There are power conditioners in the market that are very quiet and work quite nicely.

enjoy

One thing I have noticed, the hum in mine stays the same, no matter what's plugged into it, or if nothing at all is plugged in. THEY HUM..
Maybe the DC offset thing millercarbon offered up is an option.. I'd like to quiet mine down too. I use to have Topaz, Nothing like these..

I'll open one up and look, just need to be careful and discharge the caps a FEW times. I'll take some pics...

Regards

If not DC offset, it could be that the transformer is not mounted solidly in the chassis. There are members here who know how to correct this.
Or it's simply a transformer that hums.

From various contributions from members who also actually own this model it does appear to just be the fact that it is a hummer, period.
Now you may be able to reduce that with damping either external or internal but if it truly bothers one it might be time to look elsewhere.

It does not appear to be DC offset at this stage.

@oldhvymec  

While I would love to see what you find out, I do hope you know what you’re doing...please stay safe!

Arvin

@uberwaltz  

Yes, the more I researched around other forums (including at Tripp-Lite) the more I understand this to be a unit that has a hum...some louder than others. 
The other thing is that I did read about how some users/techs eliminate such a hum by using rubber grommets to isolate the transformer from the chassis...similar to what @lowrider57 suggested. 
All in all, I can live with it...just wanted to know if an easy fix was possible. 
Again, Thanks everyone for your input!

Arvin

arvincastro OP80 posts03-17-2020 6:53pm@oldhvymec  

While I would love to see what you find out, I do hope you know what you’re doing...please stay safe!

Arvin

Arvin you are a fine fellow, and I will. Here is something my brother, whom I love only like a brother can, taught me. BTW he's retired now but a good and SAFE electrician, by all of his piers. Not me, I know he is..

WHEN the circuit is hot....YOU know it's hot, you know because YOU CHECKED.

Put one hand in you back pocket. PUT ONE HAND IN YOUR BACK POCKET..., hold your pocket. now work with the other hand..

It has never failed me working around a lot of 5-200kv gen sets. Confined space and visual issues.. Trailer mount enclosed..

In this case, two handed and unplugged, to remove the cover.
Find the caps and discharge them. simple to do, BUT noisey
sometimes..pops and such. I use a simple 40 watt bulb #12 wire with
wire clips and a light switch in an elect box..Clip both sides of the caps and flip the switch, a couple of times... and go to each one a couple of times...AGAIN in the box: use one hand to connect, and one hand in you pocket..

Then flip the switch. if you like a little distance. hee hee use longer leeds.. 

WHY??? You don't want it to go through your chest, the discharge can hurt you but through your chest... ok HAND IN YOUR POCKET.

holes in the shoes is a no no too. ok.. water is a no no. NO WATER, or liquids..EVER...DAMP flooring or kneeling is a no no... the path to ground can be a real issue....

Regards

By the way. AVA sells their gear with a 30-day return period, so if you try a HumDinger, it can be returned if it doesn't help.

Ok I took it apart.  I'm gonna put a better conductor in the box and hard wire mine in with a shorter cable and a pure copper end.  It has some very small caps inside on a logic board. NO problem with having to discharge ANYTHING....
The transformer has 4 corners, two are secured through the faceplate via the front handle and two are secured directly to the faceplate.  NO vibrational dampening of any type. 
Silicone is the best. Make sure it's NOT for ultra high temp. They use nickel, lead, or tin ALL conductive in some of the cocktails with silicone to get the temp rating HIGHER.
Clear silicone is fine temp wise.   I'm gonna look for silicone washers to go between the two mating surfaces. Fireproof dampening stick on stuff, or I'll just run beads of silicone the length of the enclosure let it set up. Thin bead of silicone on the mating surfaces and put it back together.

I used a thermal gun BEFORE the upgrade after an hour of running 85 degrees, room temp was 70.  We'll see if there is any change temp wise, after the silicone.

It is just a noisy enclosure. Should be easy to fix...

Regards

@oldhvymec

Thanks for the report and I am very happy to hear it wasn't too trying a chore for you!  I actually sent your findings to a friend of mine who happens to be an electrician and he said it looks pretty straight-forward...we're hoping to meet up sometime after this COVID-19 business allows us to try silencing the enclosure as you've stated.

Thanks again...Hope you and yours are well!

Arvin 

I took it apart and just used silicone, about a half a tube. I checkerboarded the inside and gave it a little smear. I didn't remove the transformer, I just put a good amount around, the mounts. I also wiped a thin layer on one side of the mating surfaces. Next day back together, about half the noise. I cut two pieces of  in/outdoor carpet close to the same size, one top one bottom, and placed an active XO on top. Pretty quiet now. About 1/2 again. I think with a stick on sound killer, 80% of the noise will be gone.  I'm at about 60% with the carpet..and silicone..

Regards