on 18.04.2004 11:45, Rob at [EMAIL PROTECTED] wrote: > Thank you Paul... for your continued help! > > Do you think it will be 'ok' to go ahead and short pins 1 and 3 (as > this machine was bought) as well as 2 and 4? of the 6 pin front Audio > header? Or do you think I should find a S900 venus front audio board? > > It appears I can only get sound out of the rear port (through a mini > jack to double RCA). If I insert the inner section of the RCA plug > only. Thus if the outer connection (left and right) is mated no audio > is available. > > This is frustrating... I can deal with the 30 changes of PCI cards to > make OS X run, but this audio issue might be a show stopper for me. I > do not think I can make a sound card work in this machine. >
Rob, Be of good cheer; one of the reasons I'm a little vague about the built in audio chips is that I've never needed them because I've always used a PCI audio card. My first J700 is still doing nicely with a DigiDesign AM III card, one S900 has a MOTU 2408 in it, the other uses a Metric Halo MI/O thru FireWire. Each easily handles 16 tracks of audio at 44.1k/24 bit. The major limitation they inherit from the x500 class of PowerMacs after which the UMAX MOBO is designed: the PCI bus is easily saturated if the bandwidth available to external drives isn't managed. [Historically, this is why Digi's earliest rigs included their own proprietary SCSI controller in order to reduce PCI bus traffic.] You can go ahead and experiment with the jumpers. AFAIK, they are only control voltages, but even if they are directly in the audio path [in which case a *very* small dab of petroleum jelly might be just the thing to prevent corrosion on the contacts], what you have reported so far indicates that they are designed to be shorted. Let us know what you find, as I don't believe the logic has been well documented. You might want to play around to find which jumpers control the built in speaker, too. While having the built in speaker isn't essential for your purposes, it can be very useful as a diagnostic tool to be able to hear the sounds a computer makes at start up. It sounds as though you need to take a good look at the MOBO connection from the built-in speaker and the rear jacks. It shouldn't take too long to figure out how to set it straight. Check that the jacks themselves are not bent. Also be sure that the adapter *splits* the stereo channels to two RCA jacks and doesn't just *sum* them to two instances of a single mono channel. OTOH, perhaps the pins ought to be jumpered 1-2, 3-4, not 1-3, 2-4 ;) 1 3 5 | | | 2 4 6 not 1_3 5 2_4 6 If indeed the pins are in the audio path, rotating the jumper positions would have exactly the effect you describe. Peace, paul -- Paul F. Henegan <[EMAIL PROTECTED]> -- SuperMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | Service & Replacement Parts [EMAIL PROTECTED] | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> SuperMacs list info: <http://lowendmac.com/supermacs/list.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/supermacs%40mail.maclaunch.com/> --------------------------------------------------------------- >The Think Different Store http://www.ThinkDifferentStore.com ---------------------------------------------------------------
