C64 sound problems

[David Betz]

>> Is there anything other than a dead SID that can cause sound  
>> problems  on a C64?
>
> How are you outputting the audio and video?  There is a built-in RF  
> modulator with an RCA connector that outputs VHF to a television,  
> and there is an 8-pin (5-pin on really old C64s) audio/video monitor  
> connector that converts the audio to an RCA plug that plugs into  
> your monitor or an audio system.

I'm using the 8 pin A/V connector.

>
> If you're using one, try the other.

I haven't tried that yet. Good idea.

>
> If you're using a monitor cable, it's possible you have a bad cable  
> or forgot to plug in the audio connection.

I have a cable with a DIN connector on one end and four RCA plugs on  
the other. I've used a multimeter to determine which RCA connector is  
connected to which pin on the DIN and have used the RCA connector that  
connects to DIN pin 3 for audio output and the one that connects to  
DIN pin 4 for composite video output. Is that correct?