CMX-2

[Pauly]

Plus, ground loops usually don't make the transformer hum. It's usually just the speakers.

Keep in mind that the transformer bolt on the XPA-5 is pretty hard to get to. I had to take the face plate off and disconnect a wire to make enough room to get my wrench in there.

[hpc]

Jun 18, 2012 17:30:22 GMT -5 weird23 said:

Jun 18, 2012 16:19:36 GMT -5 Pauly said:

Hmmm, that's too bad. Have you tried tightening the bolt on the transformer?

I have not, I'll give it a try.

I don't think it's ground loop as none of the other amps in my system hum, the XPA-5 is the one and only culprit of any noise.

Stand corrected - returning my Effective Reading certificate as I overlooked the amps doing the humming (which would be transformer).

Out of curiosity, if you place you other amp(s) in the same outlet,
do they hum?

Yeah, it's comparing apples and oranges, but I'm guessing there is
some commonality in power supply components/layout in EMO gear.

[matt]

Emotiva tends to use toroidal transformers, and that transformer design combined with its high power design may be more sensitive to DC offsets.

[weird23]

Jun 19, 2012 17:43:48 GMT -5 hpc said:

Jun 18, 2012 17:30:22 GMT -5 weird23 said:

I have not, I'll give it a try.

I don't think it's ground loop as none of the other amps in my system hum, the XPA-5 is the one and only culprit of any noise.

Stand corrected - returning my Effective Reading certificate as I overlooked the amps doing the humming (which would be transformer).

Out of curiosity, if you place you other amp(s) in the same outlet,
do they hum?

Yeah, it's comparing apples and oranges, but I'm guessing there is
some commonality in power supply components/layout in EMO gear.

I use the XPA-5 for my surround speakers and at one time did have a hum through the speakers as well as the amp. At that time I tried the PS-Audio Humbuster III which had no effect on the hums coming from the speakers or amp. My stand is filled to capacity and it's hard to keep all the cables perfectly separated, so I tried some aftermarket power cables and that cleared up the hum from the speakers. The particular combination that worked with that problem was replacing the power cable on the plasma and the XPA-5, I guess they were too close to one another. I can't say that the power cords changed the sound any but the difference in shielding was the big improvement.

Nothing I've tried has eliminated the transformer hum that is coming from the XPA-5. I have since added three Antec AV Coolers as some components were running a little too warm for my taste and I can't hear the hum over the fans anymore so it's not a big deal. The other thing is it's a major pain to send anything back to Emo headquarters from Canada, it's pretty much the same cost if I just sell the amp and order a new one. Dealing with customs can also be a major headache as well.

I haven't tried the amps on the same circuit, I've got the three XPA-1's running through one PS-Audio PPP on a 20 amp circuit and everything else except the subs running through the other PPP on a 15 amp circuit.

[Deleted]

Nimikipod wondered:
"Two questions:
1. could it handle two XPA-1'S, an XPA-5 and the XMC-1 ?
2. How is it better than other similar products ? "

No. I'd get one for each XPA-1s and one for the XPA-5/XMC-1. But you better make sure you really need these devices before you go throwing money about...

-RW-

[Pauly]

I got my CMX-2 today. But I also got my Mini-X, so it's been getting all of my attention so far. I can say though, that the CMX-2 did cut down on the transformer hum in my XPA-5. Not all the way, but it is quieter. I'll give it another listen later on when the kids are in bed and the house is a bit quieter. So far it's good though. It's also built very well, and looks incredible. Very nice product overall.

[jedinite24]

Jun 22, 2012 21:50:08 GMT -5 Pauly said:

I got my CMX-2 today. It's also built very well, and looks incredible. Very nice product overall.

Morning folks

Couldn't agree with this more. Physically the CMX-2 is very solidly built and looks great.

I'm just putting this out there as an FYI. I was hoping to use the CMX-2 to quiet the humming noise of my Topaz 1 kVa isolation transformer and after first listen I don't believe the CMX-2 did. I'm thinking it is just the nature of the Isolation Transformer itself and there was only so much the CMX-2 could do.

This is what I was hoping to have the CMX-2 quiet.



I'm leaning towards keeping the CMX-2 because I could use all the non-current limiting power cleaning I can get. Plus at the sale price it is wallet friendly and quite nice looking.

[roadrunner]

Jedinite24

You might try decoupling the isolation transformer from the surface it is resting on. I have found a lot of gear emits resonant frequencies that are amplified by the surface is sits upon. Often decoupling cures the problem. Good luck.

[roscoeiii]

To resurrect a thread here.

I am also interested in this product to reduce the toroid hum on an isolation transformer: an Equitech 2Q.

I am wondering if other folks have had any luck with using this before another power conditoner?

And I have 2 more specific questions:

1) is this current limiting in any way? I have had experiences with other power conditioners negatively impacting the dynamics of my amps. And this would be coming before the power conditioner that has EVERYTHING plugged into it.

2) if the toroid hum is inaudible from the listening position (if I can move the Equitech farther away from me, which I am not sure is possible), is there any additional positive benefit from the CMX-2 on the sound of my system?

[cawgijoe]

I just purchased the CMX-2 because it was such a great deal. I probably don't need it, but was wondering if the following can be done without detriment:

I have all my equipment plugged into two separate surge protectors. One is a Monster home theater surge.....the long square nice metal one. The other is an Adcom ACE-515. My Acurus amp is plugged into the Adcom in one of the plugs meant for amplifiers. I do have an XPA-5 that will replace the Acurus but I can't use that till Christmas.

I listen to music at moderate levels and the same for movies.

If I plug both surge protectors into the CMX-2...........will that be ok?

Any thoughts are greatly appreciated.

[monkumonku]

Dec 14, 2012 9:03:47 GMT -5 cawgijoe said:

I just purchased the CMX-2 because it was such a great deal. I probably don't need it, but was wondering if the following can be done without detriment:

I have all my equipment plugged into two separate surge protectors. One is a Monster home theater surge.....the long square nice metal one. The other is an Adcom ACE-515. My Acurus amp is plugged into the Adcom in one of the plugs meant for amplifiers. I do have an XPA-5 that will replace the Acurus but I can't use that till Christmas.

I listen to music at moderate levels and the same for movies.

If I plug both surge protectors into the CMX-2...........will that be ok?

Any thoughts are greatly appreciated.

I have a couple of CMX-2's. I asked Lonnie the same question before I bought them and he said it is fine to plug surge protectors into the CMX-2 as it will not do any harm to anything. The CMX-2 does not limit current.

[efjay]

For what its worth:

I bought a CMX-2 to remove hum from the transformers of my amp and power supply for my DAC. When both were plugged directly into the CMX-2, the hum disappeared. When plugged into a Belkin surge protector plugged into the CMX-2. the hum returned. It appeared to me that the hum was only removed when the item that hummed was plugged directly into the CMX-2.

[Jim]

Well, I just jumped on the bandwagon and bought a CMX-2...... Not really looking to do anything magical, but it looks well built, the price was right, was curious to try it out.



I got a new Fluke 115 meter recently, and was surprised at how much (measurable) DC voltage there was.. So curious to see if the CMX-2 cleans that up or not. (Looks like you need a scope to actually measure offset accurately though)

[jedinite24]

Hi Jim

Definitely share your findings when you get your CMX-2. I'm very interested. I was noticing about 2 volt differences between the voltage readings taken from the socket vs reading taken from a CMX-2. I was using a Kill A Watt at the time. I still can't find my voltage meter to double check.

[Jim]

Jan 11, 2013 11:57:23 GMT -5 jedinite24 said:

Hi Jim

Definitely share your findings when you get your CMX-2. I'm very interested. I was noticing about 2 volt differences between the voltage readings taken from the socket vs reading taken from a CMX-2. I was using a Kill A Watt at the time. I still can't find my voltage meter to double check.

Definitely, will do. I have a couple Kill A Watts too.

I was excited to get a Fluke, because I got inconsistent results with my cheapie meters (measuring AC or measuring DC on an AC line).

I have an ION Energy Meter (7550?) that I can do waveform measurements with but unfortunately it's hard wired. It's cool to see what the waveforms look like (or watch THD and specific orders of distortion). I'd love an oscilloscope, I should put that on my"to buy" list..

I bought the CMX-2 for my 2 Channel setup.......... that I'm going to slowly piece together.

[Jim]

Jan 11, 2013 11:57:23 GMT -5 jedinite24 said:

Hi Jim

Definitely share your findings when you get your CMX-2. I'm very interested. I was noticing about 2 volt differences between the voltage readings taken from the socket vs reading taken from a CMX-2. I was using a Kill A Watt at the time. I still can't find my voltage meter to double check.

I was just playing with a Kill-A-Watt (for some reason I have 3, yeah, don't ask).

Surprisingly 2 of them never seem to fully agree on the voltage, and they're both off by .3 volts or so from my Fluke. But, I guess that's pretty close to their rated .2% accuracy tolerance. WEIRD, the Fluke 115 is rated at 1% accuracy for the range I'm measuring (115V, 60hz).

The more I learn the less I know I'd still trust the Fluke over the KillAWatt..

[Jim]

Got the CMX-2! The thing is built LIKE A TANK! I'm really impressed. My only little nitpick is that one of the status LEDs is slightly crooked - so it looks a little dimmer than the other.

Indeed, the voltage does measure about 1 V lower w/the CMX-2. It's not the cord to the CMX either (that tests same as wall outlet). I'm guessing that it's the filter circuit that's dropping the voltage a little bit (I don't attribute it all to noise being filtered.) But 1V is pretty negligible. I've played with my Fluke, but none of the DC measurements are really meaningful...Need a scope if I really want to delve in.

Definitely one of the beefiest power strips I've ever played with.

[monkumonku]

Jan 15, 2013 11:46:30 GMT -5 Jim said:

Got the CMX-2! The thing is built LIKE A TANK! I'm really impressed. My only little nitpick is that one of the status LEDs is slightly crooked - so it looks a little dimmer than the other.

Indeed, the voltage does measure about 1 V lower w/the CMX-2. It's not the cord to the CMX either (that tests same as wall outlet). I'm guessing that it's the filter circuit that's dropping the voltage a little bit (I don't attribute it all to noise being filtered.) But 1V is pretty negligible. I've played with my Fluke, but none of the DC measurements are really meaningful...Need a scope if I really want to delve in.

Definitely one of the beefiest power strips I've ever played with.

I have a couple of these. I don't know if they really help anything but I agree, they sure are built like a tank! They must have used the general idea from their remotes, like the ERC-2 or XSP-1 remote. ;D

[Poodleluvr]

I originally bought a CMX-6 since I thought it did the same as the CMX-2 but offered 4 more outlets for 25 bucks more. I thought that was a no-brainer. Not so!

The end result was I was impressed with the build quality. Exceeded my expectation. I then ordered another CMX-6 and then a CMX-2. I then ordered another CMX-2 and should get that today.

I will then have two CMX-6s and two CMX-2s. $350 total for all.

All my stereo equipment takes up ALL the outlets in one CMX-6, then I plug the CMX-6 into the CMX-2. That leaves one outlet open on the CMX-2 for a future powered subwoofer.

My TV and cable box is currently plugged into the other CMX-6 and will be plugged into the CMX-2 that I should get today. That leaves 4 outlets open for future expansion on the CMX-6 and one outlet open on the CMX-2.-- Room for even another future powered subwoofer.

That's my setup with 20 amp breakers in the main A/C service panel.

NOTE: My XPR-1s plug fine into either a CMX-2 or CMX-6 without modification.

[Jim]

Jan 15, 2013 12:15:00 GMT -5 monkumonku said:

I have a couple of these. I don't know if they really help anything but I agree, they sure are built like a tank! They must have used the general idea from their remotes, like the ERC-2 or XSP-1 remote. ;D

I like the fins on the side.. It's like it could dissipate heat!

The little bag of screws for mounting is a nice touch too!