Help please

[ZippyTs]

So I got the new setup installed and finished today. Now its just tweaking other than this terrible hiss/white-noise static sound. it is quite loud and very noticeable. Any thoughts on what it might be? I have attached a pic of preamp setup, and can draw out anything else if you need it.

also here is a link to the noise recorded from my phone first at the tweeter then at the midrange from about 6" away from speakers.

 

[Perry Babin]

Does it make the same noise if you plug a single set of RCA cables (directly from the head unit, bypassing the crossover) into each of the inputs on either amp?

Be careful if the tweeters are directly connected to the amplifier.

 

[ZippyTs]

As of yet I have not tried, but will try tomorrow. though all speakers including sub does it. just on speculation I think its the sony. I will also take a pic of it all too so you can see the layout.

Also forgot to mention it does it with the car off or on, and there in not any pitch or change in tone/sound with different rpm's and such.

 

[Perry Babin]

If it does it with the head unit alone, check the shield ground on the RCA outputs of the head unit.

 

[ZippyTs]

well after disconnecting the sony the sound is all gone. I guess the sony is booboo. Lucky I only spent 5 bux on it. Perry is that something you could repair or should I try it myself (i dont have a scope yet)

 

[Perry Babin]

It may simply have an open shield ground. Pull the board out of it and see if there are any burned traces or bad solder connections on the RCA jacks.

 

[ZippyTs]

They all look good, I am waiting for my iron to warm up and i will hit them all again

 

[Perry Babin]

Do you read 0 ohms from the input shields to the output shields on the RCA jacks?

 

[ZippyTs]

the 3 input shields read .4 to .2 ohms using a fluke 117 meter. output shields are all open
input to output or output to output reads open

 

[Perry Babin]

I would expect the output shields to be connected to the input if the input shields read ~0 ohms between them. The output shields are almost certainly supposed to have continuity between them.

 

[ZippyTs]

I connected the RCA daughter board back into the main board and I get 2.1k ohms between the input and output, and I get 0 ohms between the outputs

 

[Perry Babin]

Does the crossover have a power transformer in it?

Can you post a photo of the guts?

 

[ZippyTs]

yes it does, and here it is

 

[Perry Babin]

What model is this crossover?

 

[ZippyTs]

xec-1000

also if i probe from ground terminal to rca shields, input i get 2.1k ohms, and output I get 0

 

[Perry Babin]

What's the DC voltage on pins 4 and 8 of IC701?

 

[ZippyTs]

13.47v from 4 to 8

 

[Perry Babin]

If it's approximately ±6.5v from ground, that's OK.

Do you have any way to trace the signal through the XO (other than with a multimeter)?

 

[ZippyTs]

I get ±6.5v from ground.

All I have is a multimeter. I want a scope, but I am out of work so I cant buy one

 

[Perry Babin]

Do you have anything like an old home stereo receiver that you could use?