Is my amplifier going?

CinderLyon

At one point i disconnected everything but one speaker. But I am going through and checking everything again, so i will put that on my list to try.

How would i test for a grounding loop problem?

CinderLyon

My best friend, who is an engineer says that faulty wires in the house might not be caught by a line conditioner if under load, and my symptoms suggest a power issue. So he had me go out and look at my circuit switch box, suggesting that I tighten down all the wires connection screws. Wires seem to deform under pressure and time and connections can get weak he said.
I went outside to take a look at the circuit box, and even the bolts on the cover are highly corroded (i live in a high acid rain environment that rains over 150 inches a year, Hawaii). Since it was raining I decided to wait for a clear day to get in and tighten everything down.

cnh

CinderLyon wrote: »

ok this was fun I plugged in my cd player, something I have not done in over 5 years. I have been happy with my computer being the source for a long time given that I did not have my higher end equipment available to me due to living situation. First thing I noticed is I had a hard time getting my cd player to close. One of my all time favorite CD's was stuck in it. I had been looking for that sucker. Then I noticed that my CD player was SACD capable! woot!

Ok so back to the issue. I may have been sensitized to listening for the funny sound so I kept thinking I was hearing it, but less so. So I gave it sometime. Then I decided to bypass my amp. And I still thought I was hearing it. That was good actually. I could rule out my amp. woot! Then I decided to move the one speaker over a bit. That seemed to help as well. Then I tried to listen to the same track on my computer and it seemed worse, so I swapped in and out of sources for a while. It was a bit worse on my computer and it showed me just how good my CD player is! woot!

Back on my computer now and it does not seem as bad, hardly even noticeable really now. Moving my speaker seem to be the best solution so far. I will have to give it some time and more different music test to know for sure.

Thanks guys for pointing me in a good direction to test. I am convince that my amp is just fine now.

So now i get to spend my hard earned money on a good sub.

Call me stupid. But have you tried listening to this track on your computer through a set of decent H-phones in order to see if you can hear the SAME distortion.

Adcom 555s are incredibly durable. I have one. No problems whatsoever. Not in use at the moment though. They're also VERY easy to service. Especially the two channel versions like the 545 and 555, etc.

cnh

F1nut

Your breaker box is outside??? Never heard of that before.

A ground loop issue would be a constant hum, you couldn't mistake it for anything else.

zane77

The house I owned in the LA area had the breaker box outside and the rental house we have in town now, has the breaker box on the outside of the house. Seems screwy to me but when I built this house I wanted the breaker box inside to help weather protect the connections.

BlueFox

To my knowledge, every house in my neighborhood has the breaker box outside attached to the back wall. The power lines run between the houses over the property line separating the backyard. Mine has an enclosure with a door for access. It keeps the rain and sun off, and does not appear to be adversely affected by being outside.

CinderLyon

cnh, i have not tired headphones. That would be a good test. I only own usb head phones at the moment, not 1/4 inch. But I could still test with that. I have switched out my digital avr for my analog pre amp and still hear it. I have also gone analog CD direct to preamp, and digital CD direct through avr, and computer sources. I think these are equivalent tests. It is definitely not my amp, since i hear it when going AVR direct. It is not my speakers either since i can hear it on all speakers (worse on the left side, but that is probably my environment and/ears) . Its not my AVR since i hear it on my preamp.

I am down to wires and some sort of induction, or power source. I suppose it could be my amp is not powerful enough to drive my speakers at higher volumes but somehow I doubt that. I don't listen to music or HT all that loud. mostly below 75db sometimes higher but not by much; 80db tops. Oh, and I have not completely ruled out environmental sources or that I have a rattle in my head. Though i did stomp around my house (post and pillar foundation, big woofer!) and removed several noise vibration sources. And I did clean out my ears lol.

The meter and breaker box are side by side on the outside of the house. And show considerable signs of weathering and rust. clear evening so far, so maybe i can get in there and tighten a few wires down. I do not feel like glowing while on that task.

F1nut, no humming. When I got in and dusted out my amp, the low level background hiss heard when near my speakers went away completely. Dead quiet now when no music is playing.

tonyb

CinderLyon wrote: »

and even the bolts on the cover are highly corroded (i live in a high acid rain environment that rains over 150 inches a year, Hawaii). Since it was raining I decided to wait for a clear day to get in and tighten everything down.

Always disconnect power before attempting anything in the circuit box. Since it is outside, any bare wire exposed will oxidize more quickly than an inside wire. This could be your problem. Check all wires with the power off, see where the box is grounded too as that wire is very important to line noise. Anything that doesn't have a nice shiny copper tint to it will need to be cleaned/scraped and reconnected.

Never heard of a circuit box outside either, whats the purpose of this ?

CinderLyon

Ok well time to close this thread finally. It turns out to have been front speaker placement. I thought that I read that you wanted to offset your fronts relative to the room. Not true for fronts it turns out. I was getting constructive interference from nodes basically. I finally noticed that there was a delay in sound when I moved over a bit. So it dawned on me that I was getting time delayed stacking. And I figured out why, then went and checked out the boards. Moved my speakers to more equidistant from side walls, in a equatorial triangle relative to sweet spot and bang, noise all gone!

jeremymarcinko

Alright cool. Problem solved then. Placement derived static, I'll be damn.

BlueFox

Sounds like something loose is making a better connection after moving the speaker. It is hard to imagine speaker placement causing noise.

CinderLyon

well I did do a whole lot of changes when i moved my speakers. Everything had to move over as well. I put up some absorbers at reflection points. along the way. The room is a bit different shaped than most as well. The fronts are at the small end of a large A frame space 40 degree slopes. High spot is at 20 feet. Lots of offset wooden beams. I am sure it is a natural amplifier of all things good and bad.

Thorton

BlueFox wrote: »

Sounds like something loose is making a better connection after moving the speaker. It is hard to imagine speaker placement causing noise.

+1. This sounds more conceivable based on what you wrote what you were hearing. But I guess you can never know what could be the problem. Hopefully, you have it resolved.

nguyendot

If you took your amp out and it persists, it's in the signal path. You swapped speakers so far and it persists.
Have you swapped interconnects from source all the way to speaker?

F1nut

BlueFox wrote: »

Sounds like something loose is making a better connection after moving the speaker. It is hard to imagine speaker placement causing noise.

Agreed.

hertz9753

It could also be wire in the open basket of the speaker.