Speaker hum problem - need help

Zd and Mwsl ... yes that's good news indeed. Not sure how to put this, so please do not take it as me being snippy.

Mwsl's unfortuante experience is one of the reasons why I love ARC. My personal experience is also consistent with what I have read on ARC's web site and in various audio articles. Specifically, no unit leaves ARC's shipping dock (new or repaired) until William Gehl, ARC's offical live tester, plugs the unit into a system gives it a good listen. Mr. Gehl initials a QC card which accompanies the unit, and only then is the unit shipped out. Every ARC unit I own or have owned has a QC card with his initials. Mr. Gehl must have an incredible auditory memory.

Is the systen perfect? Does a chicken have lips? Same answer .... after all, it's run by human beings.

Anyway ... I sincerely hope that Coda puts your amp back in 100% operating condition and this is the end of your aggravation.

Best,

BIF

Jim (Jea-48) - just curious if you could say more about what/how to do the AM radio experiment. Should I actually tune into a station......or just set it to the very beginning or end of the band? What am I listening for if I set it to the station....I have very poor reception around here as I'm in a very hilly location?

Just curious about this suggestion.
06-06-14: Mwsl

Mwsl,

Earlier in one of your posts you said you tried a ground cheater on the AC power plug of the amp. Doing so ruled out the safety equipment ground being the problem.


If by chance somewhere in the 120V circuit that is feeding the amp there is a loose and or corroded connection, that could possibly cause an RFI interference in the amp and cause a buzz heard through the speakers. If there is a loose and or corroded connection an AM radio plugged into the same receptacle as the amp could/would cause a buzzing sound in the speaker of the radio because of the RFI interference being generated.

As for the AM station used, set the tuner on a moderate signal strength station. No buzz, then try a weaker AM station.

Like others have said in this thread, the problem is more than likely the amp.
Jim

I had an opportunity today to go to a local audio store. Brought in the integrated, thinking, if I can still hear the hum, and the staff can hear it, then we've isolated the problem. And, fortunately, the problem remained, obvious to all ears. It was interesting to me that after listening to my integrated hum away, the salesperson plugged in a $1000 integrated into the exact same cords, cables and connects......and all I heard was a blissful silence. For those of you who thought my amp was problematic, you are correct. Alas, I'm still waiting for the word from CODA for when they'll be ready to receive my amp for repair; the owner/founder has been out due to a severe injury, so I'm biding my time waiting for his return.

Mwsl,
Thanks for the update, I wondered what was happening.
When you get the issue resolved please let us know what needed to be replaced.
Thanks,

After much delay, I finally got my problem resolved.....and quite nicely!

Doug Dale, the owner of Coda, had been severely injured many months ago and has been off work until last week. Much of the delay that I experienced was due to Doug's absence. He was apologetic for the delay.

As soon as he got back to work, he decided to simply swap out my unit for a new one that he had tested and was sure worked to spec....with no noise. I brought my amp in today. We listened to it in his listening room and (thankfully) heard the noise....although it was MUCH quieter in his room with his Legacy speakers that it was in my room with my speakers. We then listened to the new amp that he had selected to replace mine.....it wasn't dead quiet, but the noise was of a much less obtrusive nature that he said was normal and (I believe) related to the volume control used.

I brought the amp back to my house, plugged it in and......it's lovely...no noise. Again, not dead quiet, but WAY more quiet than my previous unit. Since the replacement unit is new I'll have to break it in again, but, frankly, that's not that bad a prospect :-)

Doug did say that very infrequently, generally due to shipping issues (dropping, rough treatment) some wires get slightly loose and may cause the issue I have been having. Oh well, just bad luck on my part.

It was cool seeing the Coda facility.....there's only 4 employees (that I saw) including Doug, so it's a small operation. But they're producing some neat products.

OK, I'll check back in in a few weeks....but I'm VERY heartened with today's news. Thanks again to all of you for your support and help.