Wierd turn-on noise with my Diamond Audio d6 700.4

[rc10mike]

The problem is when the amp turns on, the music will crackle/hiss for about 1/2 second before it sounds like normal, then it sounds great. Now Ive heard of turn on thump but never this. Have you heard of this before? What do you think it might be? Thanks for any help.

BTW, I confirmed this issue in the house by using a power supply and ipod.

I opened up the amp to inspect and found this:



So what purpose do these caps serve so close to the speaker output? Could this be causing the issue?

[I Am An Idiot]

Those are not the cause of your noise.

[rc10mike]

Originally Posted by I Am An Idiot

Those are not the cause of your noise.

Ok do you know what they do, or what else can be causing it?

[1moreamp]

Originally Posted by rc10mike

So what purpose do these caps serve so close to the speaker output? Could this be causing the issue?

Those are output RC networks that clean up any out of bandwidth noise issues usually ultrasonic in nature. Most every amp has these and the Mylar caps look to have melted or have been damaged somehow. These should be replaced, and they are cheap to come by.
I agree these are most likely not the source of your noise issue but they may be a symptom of your noise issue < a by-product caused by the noise issue >

Once you find the noise issue I would replace these just for good measure...


I would start looking for bad solder joints and bad switches first. After that I would be looking into the muting circuitry and other more advanced issues. Freeze spray can be helpful in detecting bad solder and contact cleaner for the switches and pots..

[mbates14]

sounds to me the amplifier is oscillating parasitically, bringing the zobel filters into a short circuit thus killing your caps.

[rc10mike]

I had the amp completely apart and didnt notice any bad solder joints, all though I did touch on some that looked a little funny.