Left channel hiss on a Yamaha CR-2040

[bullduck]

Ok, so I just bought headphones and noticed for the first time that there's a hiss on the left channel. I checked if it was also there on the speakers and sure enough it is.

I'm wondering where to look to rectify the problem. The hiss is there even at 0 volume and regardless of input selected. With no inputs connected, still there. I fed the tape out and the preamp out to another amp and the hiss transferred to the other amp so I guess the problem is not in the amplifier section. The only thing that made any difference was switching to mono at which point the hiss was almost inaudible.

Any suggestions? Thanks in advance!

 

[avionic]

Deox-it!!

 

[bullduck]

Deox-it!!

Already done. Any other thoughts?

 

[avionic]

Well if its not a dirty switch.Then its going to be a noisy component ie. capacitor,transistor etc. Or a cold solder connection.

 

[bullduck]

Well if its not a dirty switch.Then its going to be a noisy component ie. capacitor,transistor etc. Or a cold solder connection.

Understood, but my question is how do I pinpoint which component is noisy?

 

[avionic]

Do you have a oscilliscope and a audio signal generator?

 

[bullduck]

Do you have a oscilliscope and a audio signal generator?

I have neither.

 

[avionic]

Do you know how to read a schematic?

 

[bullduck]

Do you know how to read a schematic?

yes, and I have the schematic for this unit.

 

[avionic]

Do you get the noise with any source ie.tape deck-CDP etc.

 

[bullduck]

Do you get the noise with any source ie.tape deck-CDP etc.

Hiss is always there with or without a source. As a reminder, I wrote the following in my initial post:

The hiss is there even at 0 volume and regardless of input selected. With no inputs connected, still there. I fed the tape out and the preamp out to another amp and the hiss transferred to the other amp so I guess the problem is not in the amplifier section. The only thing that made any difference was switching to mono at which point the hiss was almost inaudible.

 

[avionic]

Wiggle and toggle the adapter switch on the rear panel .See if it changes the noise or not.

 

[bullduck]

No impact. To be clear it's not a scratching sound like you get with a dirty control, it's more like a steady white noise. Sort of like tape hiss.

 

[avionic]

Your kinda screwed without any test equipment to signal trace through the audio path. Guess you could shotgun the electrolytic caps between the input selector switch and the amplifier modules,cross your fingers and hope.

 

[EchoWars]

Break it down...figure out if it's in the amp or preamp first.

 

[avionic]

fed the tape out and the preamp out to another amp and the hiss transferred to the other amp so I guess the problem is not in the amplifier section

Looks like he do'd that already.

 

[bullduck]

Your kinda screwed without any test equipment to signal trace through the audio path. Guess you could shotgun the electrolytic caps between the input selector switch and the amplifier modules,cross your fingers and hope.

ok, thanks for your help.

 

[EchoWars]

That's what I get for skimming.

 

[avionic]

Glen , they need skimmers down on the gulf coast..

 

[jan_stevns]

they told on the news a big oilskimming ship had arrived ....