XDA-2 hum?

[cdifpsycho]

I recently pulled the trigger on the airmotiv5s and an XDA-2. First time user of emotiva. It is definitely well made stuff! I was struggling to get wife approval with airmotivs but she likes them now that they're here!
My problem begins and ends with the XDA-2. It has a very slight hum. I do have it plugged into a surge protector and I will change that out several times later today to see if that helps. BUT:

1. The hum gets worse any time you press the dimmer button until you get back to 5. Is that normal?

2. What is a normal /acceptable level to turn the airmotiv5s up too? When I am have the volume turned up, I'm listening with it cranked up to -10 to -7.5 (with +10 being the highest). Could that be the source of my hum?

Any help at all for this noob would be appreciated. So far I love the set up for what it's intended for... Now just testing for how versatile it is!

[cdifpsycho]

And I know the hum is from the DAC because it does it with the airmotiv's unplugged and turned off. Speakers are normally connected with RCA cables

[drtrey3]

Is the hum in both channels? If not, switch the cables and see if the hum switches, if so, bad cable. Also switch the cables from your source to see if a mono hum switches channels. I would also mess with what is plugged into which outlet.

Trey

[AudioHTIT]

Jul 25, 2014 10:32:46 GMT -5 cdifpsycho said:

And I know the hum is from the DAC because it does it with the airmotiv's unplugged and turned off. Speakers are normally connected with RCA cables

So you're saying you get the hum with the speakers turned off? That sounds like mechanical hum, possibly from the transformer. I've owned both an XDA-1 and 2 and have not heard any mechanical or electronic hum from the device. However, I do have a fluorescent light near my Airmotive 5's and I'm using a 3.5mm to RCA adaptor to deliver signal from my Mac-mini, I do get a slight buzz when the fluorescent is on. First confirm you get the hum with no speakers powered. Since you have the option with that combo I'd also use XLR's, if your hum is electrical I'd try that as a solution, you can get an inexpensive pair from Monoprice.

[mercury]

It might be a hum from the toroidal transformer of the XDA-2. The CMX2 might eliminate the hum, not sure though.