I am among the old and cranky of whom Crash speaks. I am setup to use the d8b either as originally intended or as a controller for D8Bridge; I have a data switch
http://www.d8bforum.com/phpBB3/viewtopic.php?f=6&t=696 that selects either the d8b CPU interface or the D8Bridge host computer interface. I am also on a quest to quiet my d8b CPU/PSU. My ultimate goal is to have my d8b running in the same room as I have open mics and have that not be a problem. This is a quest for an absolutely silent d8b. There are things you can do to quiet the thing down, such as replacing the 50mm CPU cooler fan wiith a less grumbly one (did that), and swap out the hard drive for a Compact Flash card (did that too).
But the most aggregious offender is the d8b's Sparkle AT CPU PSU cooling fan. I have been experimenting with a Seasonic fanless ATX PSU and I'm trying to work out some of the kinks, but there's a good article in the database by Steve Hammond describing how to adapt a quieter ATX PSU to an AT environment. There's another good article directly below it addressing the Compact Flash modification.
I'm also looking into a fanless cooler for the CPU. What I'd ultimately like to have is a completely silent d8b CPU/PSU, no fans.
All of these things involve physical changes to your d8b CPU/PSU and a level of comfort and competence with electrical/electronic gizmos. If you're OK with that or you know a good tech, there are definitely some things you can do to improve upon the racket the CPU/PSU chassis makes.
I'm not sure about the advice to remove the fan from the CPU and rely only on the stock heat sink for adequate cooling. Marc may be right about that but I'm not so sure. I'm trying to locate fanless coolers for the Socket 370/462 that might do the trick.
As far as D8Bridge goes, all you really need from the d8b CPU/PSU chassis is to get the console voltages to the console; all the comms are between the console and the D8Bridge host computer. You can remove the Celeron CPU and HDD and still accomplish that. Your d8b CPU won't boot but you don't need it. You still need the CPU's Sparkle PSU (or an equivalent but quieter version) because it supplies AC and DC voltages to the Mackie power supplies.
I almost forgot - there's another cheaper and easier approach if your situation permits, just move the d8b CPU/PSU to another room or inside a closet.