The Quadra 700 goes thru extensive initalize routines of its hardware,
read's PRAM, obtains all info from last session including the volume
setting, and then executes the sound procedure for the startup sound, and
wait's on the SCSI controller to respond to the boot up code.


If the DRAM produces an error, or a registers cannot be read from a device,
or the device corrupts that address/data or control paths, then if it is
possible, the firmware branchs to another sound routine that produces the 
'sad mac' sound.


This is a general breifing of the start up procedure of a typical mac.
If you cannot control the volume of the quadra, even at boot up, then i feel
there is something incorrect with the logic board. 

My Quadra 700 does not show the problems you are having.
