Background on my situation.
Took a bit to get the first ADA1500 after ordering new speakers this past year. Leaving aside the conversation on customer service (see previous thread link), when the new ADA arrived (January), all was well for a bit. Sometime around early May i noticed no sound coming from my left front drivers.
After some basic testing, it was determined one of the amp modules was not working.
Sent it back to Axiom.
After extensive time at Axiom, the amp came back (late August) checked and repaired (this first amp apparently failed in some manner that they had never seen before; i have no more specifics than that). When i opened the box and took the amp out, i heard something rattling. I popped the lid off to find what looked like a metal jig or maybe a heatsink loose inside but i couldn't see anywhere that it would have been attached. I sent a pic to Axiom and it turns out it was a piece of a shield on an inductor and that the amp was not usable. They figured the only way that could have detached was if the amp was dropped really hard. I'm a bit uncertain about this. Just how high would that box have to be dropped to have this part detach?
Or was it insufficient application of an adhesive from the parts factory?
Anyway, my original repaired amp was now headed back to Axiom....again.
On the upside, Axiom shipped a whole new one that arrived a couple of weeks later in EARLY October.
Here we are now in MID-October (only a couple of weeks after getting the new amp) and i have noticed an issue with the new ADA1500. There is a buzzing noise from all channels except for module 3 (presently hooked up to the centre channel) and maybe to a lesser extent module 4 (hooked up to the left rear channels of the LFR880).
This is an update from my earlier post in the previously noted thread in regards to how many channels in which this buzzing could be heard. I did a more thorough inspection last night assisted by the spouse.
Here is a sound bite of the buzzing (turn up your sound to hear it clearly). The first 7 seconds are recorded near the tweeters (a not untypical background hiss) and then the recording moves down to the woofers.
https://www.dropbox.com/s/jpfzz9yym...rough%20LFR880%20rear%20channel.MOV?dl=0NO OTHER ELECTRONICS EXCEPT THE AMP WERE TURNED ON AT THIS TIME.
THE BUZZING IS COMING SOLELY FROM THE AMP. I even disconnected the 12V trigger from the Denon to the ADA just to be sure.
Second, after swapping around speaker wires and determining that the sound was coming from pretty much most channels, i then opted to try and check for a ground loop hum in the only manner that i can; by changing the location of the amp plug in. Originally the amp was plugged into a quality power bar along with ALL other electronics, so obviously under this condition there is buzzing.
I then plugged the amp into the wall socket on its own.
Still buzzing.
One last thing left to try is to get a long extension cord and try a few other plugs even outside of the room (to be sure they are on another circuit), BUT, i should mention that the first ADA1500 we received did not have this problem, certainly not that i ever recall or noticed. When i first got the original ADA in January, i went to check and make sure every driver was working. I would think after 4 months with that one i would have noticed a buzz considering i've had this new ADA for only a couple of weeks and picked out the buzz sound quite quickly.
Now i'm left with a choice again; contact Axiom not knowing entirely if this is a ground loop hum specific to my home (IMO doubtful considering the non issue with the first ADA and 4 months of listening), or try to find ways to keep testing for ground loop hum issue by purchasing power cable ground lifts, etc.?
Quite honestly, i started poking around for other replacement options last night, perusing some info on other Class D amps such as ATI, Nord, Appalon, Buckeye.
That's the story.
An ADA saga that should have ended a very long time ago.
Is there something fundamentally wrong with the ADA design?
Questions, questions.
