which products reduce hum on a Solid State amp?

[Willief23]

I have an Outlaw 7500 Amp that has 2 big transformers in it so it has hummed since pretty much day 1 of owning it. Im pretty sure I have dc on the power line which is causing the hum. Which products reduce hum on a Solid State amp?

I have 1-2 filters in each room that reduce power line noise in the wall outlets by around 90-92% (tested with greenwave noise analyzer). I have 2 EP 2750 ground filters installed at the breaker panel for my home audio and computer circuits (that didnt really do much of anything). All my equipment is plugged into a PI Audio Uberbuss. I have Acoustic Zen power cords on most of my equipment with the exception of the Outlaw 7500 amp using a Shunyata Alpha V2 NR power cord. Wall Outlet is a Furutech GTX D with carbon fiber cover. All power cables, interconnect and speaker cables are off the floor and power cords are routed away from other cables.
Supposedly Puritan makes products that reduce humming from transformers with their dc offset corrector built into some of their products. I tried a Puritan PS106DC and the humming still remained. Also Emotiva CMX-2 suposedly reduces or gets rid of humming. Besides the Emotiva product and installing a dedicated line for my audio setup which is NOT an option what else could I try?

[Formerly YB-2]

Have you tried tightening the mount nuts/bolts/screws that hold the transformers? If loose, contributes to transformer hum.

If that does not work, Shunyata, AudioQuest, PS Audio & Furman (among others) all offer products that would solve your problem. As always, the more you spend the better it gets. Talk to Iavn.

[GeAllan70]

this...



https://www.morleyproducts.com/hum-exterminator/

[Willief23]

GeAllan that wont work since my amp uses 800-900watts and pulls more than 6amps

[W9TR]

If I read correctly, you’ve tried the Puritan xxx-DC and it didn’t make a difference, correct? If that’s true, I’d expect the Emotiva CMX-2 or any other DC blocker wouldn’t work either.

That leaves the toroidal transformers in the amp themselves. Most of these multichannel amps use toroidal transformers because of their small size and low cost. IDK anything about this outlaw amp, but let’s assume what I’ve hypothesized is correct. It has two big toroidal power transformers.

The width of these amps has to be 17” to fit in a 19” rack, so I’m guessing the transformers are mounted to the front panel somehow. If that’s true….

You’ll have to take the amp apart and physically isolate the transformers from the front panel with some vibration isolating/absorbing sheet stock, like Sorbothane. You’ll also have to change out any metal washers with nylon, add sorbothane to the back of these washers, etc. You get the picture. Isolate the acoustic noise source

You could also increase the mass and damping of the front panel by adding a sheet of Dynamat or something similar to the outside. For appearance sake, if there is room on the inside (doubtful) you could add Dynamat to the inside of the panel before you add the Sorbothane.

https://www.sorbothane.com/sorbothane-sheet-stock.aspx

[Still-One]

Years ago I had a hum issue that was eliminated by a out of production PS Audio hum buster.

[GeAllan70]

with this..

https://www.amazon.ca/iFi-Audio-Sile...8XWJNS9T&psc=1

and this...

https://www.amazon.ca/iFi-SilentPowe...8XWHJRZ1&psc=1

[Masterlu]

Originally Posted by GeAllan70

with this..

https://www.amazon.ca/iFi-Audio-Sile...8XWJNS9T&psc=1

and this...

https://www.amazon.ca/iFi-SilentPowe...8XWHJRZ1&psc=1

FWIW, I’m a dealer for IFI; although I have no experience with either product.

[Willief23]

thank you W9TR that is very helpful and yes my transformers are mounted on the front panel. GeAllan those might not work because I believe the ends on my power cords might be too big but thanks anyways.

[W9TR]

Originally Posted by Willief23

thank you W9TR that is very helpful and yes my transformers are mounted on the front panel. GeAllan those might not work because I believe the ends on my power cords might be too big but thanks anyways.

Since you’ve tried a DC blocker and it didn’t work then in my view mechanical isolation will be the best next step. Good luck!
Tom