Axiom Home Page Forums General Discussion Technical Questions weird problem with optical sound

This is undoubtably a problem with my AVR, but thought I'd ask here for similar experiences.

I'm driving my new Axiom HT with a Yamaha RXV-1800. So far, I've only set up the M60s, the SWFR, and the center speakers, not the surrounds. Sound is coming from a Mac mini, via the TOSLink connector.

My problem is that the Yamaha shuts down if I have any but the tiniest volume set on the Mac. The Yamaha dealer says that is the way it should be, volume should be controlled from the AVR, and the Yamaha shuts down to protect its circuitry if there's any significant input from the Mac.

This sounds pretty weird to me. It's also a real PITA, cause it's pretty hard to set, say, iTunes on the Mac so that the sound is minimal, yet still audible.

Any thoughts?

Regards,
David

I suppose the Mac's output could be extraordinarily high, but I've never heard of that happening with analog outputs. Is there an Apple Store nearby?

This is truly weird. The optical cable is only carrying the digital image of what to play. Sounds like either a defective AVR or that the MAC's connectors are optical, but they are configured for a different protocol and cause the AVR to misinterpret what it is receiving.

At least with my AppleTV, even though it is connected via optical digital only (TOSLink, just like yours), you can control the volume from it alone (like from the other room, via AppleRemote). In other words, unlike a DVD player, Apple does tinker with the "levels" coming out of the digital connection. That might have something to do with it.

I've never had any problems like you're describing, but my receiver is a Pioneer, so that's obviously going to be a bit different than your Yamaha.

But one thing I'd try first is to replace that optical cable. I've had bizarre problems with optical cables in the past that were always solved with simply getting a new cable. All it takes is one too-aggressive of a tug or a too-sharp of a bend and you start to break fibers. Break enough and weird things can start to happen.

Something to try, anyway.

One other question...

When you set the level on the MacMini to that very small but usable one, how loud is it? Is the sound level comparable to what you'd get from a DVD player, for instance? Or do you have to really crank your Yamaha way up to hear it?

On my AppleTV, the loudest setting is roughly what I expect from a DVD player. In other words, it seems like the AppleTV's volume is just a function of limiting the output.

That seems to be the case on iPods as well--you have to crank them up to get line level output. But that's the analog outs.

Thanks for the help, all. What I didn't mention was that I had the system set up as described, then decided - since doing the surrounds was going to be more work - to stop and listen a while :-) I had no problems, and I'm *sure* I didn't have to fiddle with the volume from the mini. It was only the next day, when I turned the system back on, that the problem appeared, when - theoretically - nothing had changed.

Peter, I do have to crank up the volume on the Yamaha, well past half-way, to get reasonable sound when the mini is set to minimal volume.

Soo, I'm going to:

1) See if there's any problem when I use analogue output from the mini

2) replace the optical cable

and see what happens.

Again, thanks - will post results.

Regards,
David

Hmm. Switched over to analogue input from the mini, and have the same problem (slightly different levels of volume, in fact I have to crank the AVR volume almost to the max to be able to hear it).

I think I'll check all my speaker connections again . . .

And the problem was . . . speaker connections. I disconnected everything, hooked up only the front speakers (making sure everything was tight, tight, tight), and the problem went away.

Sigh. Such a noob.

Thanks again,
David

[Quote] making sure everything was tight, tight, tight [Quote]

Sounds like a reggae song.