Back to ask again (long! sorry!)

[dogorman]

I've just finished uploading eight images to a thumbnail gallery on a hosting site called imageshack, and will post the link to the thumbnail gallery here. The thumbnails are arranged in two rows of four.

Top row (L to R) :

1) My rig, in its latent state in a rack with no rear panel and front doors open

2) Points of conduit entry to the attic above the breaker (note the small white-painted copper tube, emanating from the wall, just below the elbow of the water pipe visible at right (more about this, below)

3) Electrician-friend's temporary solution to dedicated AC-line. He had two outlet boxes of two outlets each on his truck, so he overlapped the plates a little (background). Undedicated AC line is in foreground. At the moment the CDP, Amp, and Preamp are connected to the dedicated line, and the power supply (which manages the TV and BDP) is connected to the undedicated line

4) Sample of the "controlled chaos" at the back of the stack, including painstaking attempts to ensure that power cords, IC's, and speaker cables only cross at right angles. (Power wraps have no noticeable effect on problem, f-y-i).

Bottom row, (L to R) :

5) Inside breaker-box, made by "Square-D," c.1949. The un-dedicated line serving the home entertainment rig is bottom-left, single breaker

6) Close-up of break in that thin copper tube that emanates from the wall in picture 2, near that elbowed water pipe. I cut this thing with my hedge trimmer shortly after moving in to the house, and it is affixed to an external water spigot in such a way as to suggest that it's a grounding mechanism for something

7) Close-up of the thin copper tube's connection to the spigot, directly below the break -- is this a picture of some sort of grounding mechanism? Should I perhaps have avoided grabbing both severed ends of the thin copper tube, to take this picture? (Nothing happened, by the way)

8) Close-up of the outside breaker panel -- dedicated line is top-right, and it's a split breaker because electrician-friend didn't have a joint breaker on his truck (plans to replace).

[Luvin Da Blues]

One glaring thing I noticed was your ground connection (pic009). This should be redone after scrapping the paint off the pipe 'till ya get to shiny metal and reattach.

Do you have a ground rod also, if you do check that also. I suspect that you have an unbalanced grounding path.

Cheers,

LDB

[hermanv]

I looked at your pictures and my opinion is that your power amp has insufficient ventilation. After the sound deteriorates place your hand on the amp chassis if you cant press your hand against the chassis for 15 seconds or more, it's probably too hot (most people can tolerate 55 deg. C).

I'm not saying this is your problem, but too hot is bad news and certainly could be the problem. Also I'm unsure about the wisdom of putting the pre-amp on top of he power amp (excess heat again).

[Luvin Da Blues]

Just another thought.

Does your friend live in the same neighborhood? If so maybe you have real bad power in the area. Try phoning the power company and see if they could audit the lines for noise etc.

[twc644]

Hi Dave,
I'm gonna take a shot at this and try to offer some assistance.Dont know if your handy with a soldering iron and multimeter .If so,I'd first focus on the one pair of speakers.
Check for cold solder joints and the resistors and capacitors in the crossover network.You could have a resistor drifting way out of spec or an electrolytic capacitor reaching the end of it's life--once either gets charged up it builds up too much heat possibly causing the problem as one of those items may be prematurely failing.

This info also applies to the amp. It could be something as simple as a cold or broken solder joint somewhere/anywhere in the circuit. This is something easily overlooked and yes sometimes by technicians as they are human and make mistakes.

I've done this myself before when I'm modifying or partially restoring a piece of equipment not paying attention to my soldering skills only to find a poor solder joint caused by my hands 2 days later and being extremely frustrated at myself....the result was one leg of a cap not allowing it to charge properly due to the solder joint compromised or the actual pad on the circuit board damaged.I'd touch up everyone of them and that certin channel finally worked like a charm after I found my mistake.

The hypothetical solder joint could be further down the circuit for a certain rca jack or speaker jack on the back of your amp for one of the two channels ????

One thing to do is open the equipment..another words take the top off and visually inspect the components with a flashlight to see if a capacitor is bulging or has leaked the internal electrolytic fluid..if not with the naked eye then look for any resistors/transistors where the body is discolored from overheating,. Last but not least....look for any burnt areas on the circuit board.

Could be the volume or balance control has some oxidation on the internal wipers.....you shoot some "De-Oxit" in the body of the potentiometer and liberally turn it back and forth 30-50 times to let the chemical hopefully clean the wipers inside. Lots of humidty in your home from the outside heat entering the room over time can cause this or having gas heat where it dries out your sinuses also affecting your equipment especially the volume control...it's a possibility okay.

I know you said in your post the equipment has been given a clean bill of health but something is definitely causing this and I doubt it's your imagination.No,I'm not trying to contradict anyones past comments by any means.To me, this sounds like a hardware and/or passive component problem and not psychological .I hope this info might help you out as thats some very nice equipment you own.Good luck !