Solid State amp static.

[M50'sMike]

Hello audio karma family. I just recently purchased a acurus a125x5 intergrated amp and noticed after 2 days of listening, a sound of static coming from my right front channel speaker. I did well over 5 hours of troubleshooting with my friend Audiofreak71, eliminating my rca cables, interconnects, my dac, and my pre amp as the culprit of this noise. And the amps front right channel terminals or rca input terminal was to the winner. So I asked the person I bought it from on the forum, if me and audiofreak71 could pop the hood on the amp to see if it was an easy fix and it wasnt, hed honor a return and refund. He gave the okay and we popped the hood. I eventually found on the right channel circuit board what appears to be a cold solder on what I think is the ground lead, for the right front channel. But I'm very new to circuitry but it's mostly straight forward haha. But I was hoping some of the experts, or someone who's got a lot more experience with this could confirm or deny this. I'm posting some pictures to this thread as well. Any response is greatly appreciated. Would be elated if it's a simple fix.

 

[nj pheonix]

I'm guessing you're sure it's a loose connection.
If it's just a cold solder joint (with unit unplugged!) You should be able to re flow the joint. That is, hold iron against joint, take new solder and hold at that joint (not against your iron) the idea is the all metal material at joint is hot enough to flow the solder. You just need a little bit. Also if you're around wires take special care not to touch them with iron and melt jacket.
Three other things. This is a fast operation. Don't linger on connection point for a long time. Also solder cools in about second or so but it's not instantaneous. Don't disturb (move?) Joint after heat is removed. Movement can cause a cold joint. Inspect for solder bridges after you do this. (Unintended solder connections to nearby spots).
It really helps to have a clean tip.
Before you solder. Heat iron. Touch a bit of solder to tip.
Wipe tip with damp ( more dry than wet) sponge. A damp paper towel will work just as well. Tip should look shiny once you do this. This makes for good heat transfer so you can do this quickly as described.

 

[M50'sMike]

Thank you NJ Phoenix for the detailed instructions, I appreciate them very much, I feel I should note, we are not completely 100% sure that it's a cold solder. Was worried it could've been burnt but I have not cleaned the joint to see if there is residue on the board or joint itself, was hoping for a third opinion on whether It is a cold one or not before we decide to take action. We looked over each circuit board intensely especially the two front channels, even more intensely on the right channel board because that's where the static is coming from. And this is the only thing we could find. The caps aren't bulged and everything seems pretty Mint and well crafted inside. A little dusty, but that was expected. Waiting for audiofreak71 to take a look at the thread to see what his opinion is on going ahead and fixing it, or taking a further step to better identify of it is a cold joint or not, didn't want to have to take the board off of its mount until or if I had too. Heres more unsolicited pictures of the inside. and I apologize for the poor lighting in the pictures.

 

[nj pheonix]

Just curious,
The static you describe, is it hiss? That is, like a low level white noise. Is it an intermittent popping sound?
Is it quiet, then a little noisy, then quiet again?
Also , if it is in fact in the area that you describe, hooked up and on , if you were to tap with a plastic pen or a chop stick , on or near the area in question , you should be able to create the noise with tapping.
If not, it's likely not a cold joint.
Note: I'm not sure this has been thought of or addressed.
A good cleaning of switches , controls and jacks, might solve your problem.

Looking at your pic of the back of the speaker binding post. If this I'd the area you think may be problematic , I see it's a screw terminal (rear) , with a crimped on end. If this is an iffy connection, perhaps something as simple as the nut being loose on the post. (Only attempt to tighten while off).
In that same vein ( and I feel less likely) the crimped on terminal may have a bad connection (at the point of the crimp) which would require cutting off and installing a new end (they're not reusable or repairable) but are inexpensive and easy to install.

 

[M50'sMike]

The noise I hear is not like a white noise. It's like crumpling paper or cellophane. And on my set up, it sounds like someone is sitting where my speaker is (front channels are 12ft from hot seat).and is crumpling it. It's not overbearingly loud. But it's very noticable and ruins the quiets in a movie and music tracks [[EDIT]] not just quiets but parts of songs that aren't very busy and parts of movies where it's just casual conversation. On audiofreak71's setup it's much less noticable, but still able to pick it out in the quiet parts. He has a much larger step in quality of hardware than I do. Virtually all of the dirty power and interference is taken out. I did spend an hour or two last night with a can of de-oxit and a load of q-tips cleaning the Jack's and where the leads connect to the circuit boards.(the side facing the center of the amp. And about at the 2 hour mark is when I noticed the solder shown in the picture. I will have to try the chopstick suggestion. We did check the nuts on the Jack's for the interconnects and rca Jack's. And the only one that was able to tighten further was the surround right channel. And it has had no problem with sound to begin with.

Just curious,
The static you describe, is it hiss? That is, like a low level white noise. Is it an intermittent popping sound?
Is it quiet, then a little noisy, then quiet again?
Also , if it is in fact in the area that you describe, hooked up and on , if you were to tap with a plastic pen or a chop stick , on or near the area in question , you should be able to create the noise with tapping.
If not, it's likely not a cold joint.
Note: I'm not sure this has been thought of or addressed.
A good cleaning of switches , controls and jacks, might solve your problem.

Looking at your pic of the back of the speaker binding post. If this I'd the area you think may be problematic , I see it's a screw terminal (rear) , with a crimped on end. If this is an iffy connection, perhaps something as simple as the nut being loose on the post. (Only attempt to tighten while off).
In that same vein ( and I feel less likely) the crimped on terminal may have a bad connection (at the point of the crimp) which would require cutting off and installing a new end (they're not reusable or repairable) but are inexpensive and easy to install.

 

[Jeandelyon]

Le bruit que j'entends n'est pas comme un bruit blanc. C'est comme froisser du papier ou du cellophane. Et sur ma configuration, on dirait que quelqu'un est assis là où se trouve mon haut-parleur (les canaux avant sont à 12 pieds du siège chaud) et le froisse. Ce n'est pas trop bruyant. Mais c'est très perceptible et ruine les silences d'un film et de morceaux de musique [[EDIT]] pas seulement des silences mais des parties de chansons qui ne sont pas très chargées et des parties de films où ce n'est qu'une conversation informelle. Sur la configuration d'audiofreak71, c'est beaucoup moins visible, mais toujours capable de le repérer dans les parties calmes. Il a une qualité de matériel beaucoup plus importante que moi. Pratiquement toute la puissance sale et les interférences sont supprimées. Et le seul qui a pu se resserrer davantage était le canal surround droit. Et il n'a eu aucun problème avec le son pour commencer.

Et le seul qui a pu se resserrer davantage était le canal surround droit. Et il n'a eu aucun problème avec le son pour commencer.[/QUOTE]
hello, I'm digging up the subject, I have the same problem of cracking noise. but on the 5 outputs. Did you solve your problem?