Help - MBP keeps overpowering my stereo receiver -- and is really quiet

Hi all,

My Macbook Pro keeps blowing out my stereo receiver, even though I'm playing it at a relatively low volume level.

First, I connected the MBP to a Sony receiver using an analog mini-to-RCA cable. Even though the volume wasn't all that high, the Sony receiver blew a fuse, which is going to cost me money to replace.

So I bought a Yamaha receiver, and this time I connected the MBP using an Optical cable. Fortunately, the Yamaha has a better over ride feature that prevents it from blowing a fuse, because whenever I turn up the volume even a little bit, the MBP overloads the receiver.

After doing a lot of reading, I have learned that OS X does not allow me to change the volume output of a digital source, so I guess it's not possible for me to turn it down.

But surely there's a way for me to connect my MBP to my stereo and be able to play it at a reasonable volume, right? If so, please provide me with the details.

Thanks.