DA board in a QS case?

Yes. It is basically a drop-in replacement.

The power supply has an extra 28 V line that isn't connected on the Digital Audio (and a quad-pin molex connector with 2 12 V lines and two grounds that you don't need and can't plug in anyway).

Peace,
Drew

OK, so that being said about the power supply.. what am I now missing by installing the DA board?

I know the bus is the same.. I know QS cpu's will plug into the DA motherboard.. am I going to loose something important?

I assume I just leave the molex unplugged and cut the 28V line?

James

I thought you needed the 28V line on Gigabits, and DAs?

To use a DA board in a QS case with QS power supply you will need to:

1. Instal the board.
2. Instal the processor and do the 12v modification to the 4th pin on the processor. (if it's a qs processor).
3. Remove the second 28v line from the motherboard power connector. I had a friend say his DA board fried when he connected it to a QS PS. I haven't tested it myself, but still, consider yourself warned.

Here's a thread I created that deals with the PSU question:
http://www.applefritter.com/node/21069

There are links to pages with the pinouts there.

This is all tied into the question of using an ATX PSU also:
http://www.applefritter.com/node/21844

So you could just go with an ATX tower instead of the QS case. Those QS PSU's sell for $80-$100+ on eBay, so selling the PSU out of the QS case, or the case whole, can possibly be more financially advantageous if you go with ATX instead. I still haven't got around to trying the ATX PSU on my QS yet. I like the ATX case idea because the way my machine would be installed under my desk I'd want to be able to easily open the left side of the case--as in an ATX case--and wouldn't be able to open the right side--as in a G4 tower--without having to pull out the whole computer after disconnecting all the wiring going into the back--what a hassle if you like to play around with hard drives, etc., on a regular basis.

I am running a DA logicboard in a QS case and using the DA Power supply. It also has a QS 800MHz CPU in it. So I had to do the 12V mod to use the QS CPU. It current configuration is

800MHZ CPU
768 Megs ram
DVD-R/CD-R-RW
40Gig HD
250 Meg Zip drive
Nvidia GeForce3 64meg Video
Belkin 2 port USb + the two onboard usb
Radius 3 port firewire + the two onboard firewire
OS is Tiger 10.4.10

Everything works with out issue

To repeat, the QS has an extra (as in two) 28 V line.

http://www.outofspec.com/frankenmac/wire.shtml

-
Drew

where do I find information about the 12v mod to the processor.. is this a very detailed job or pretty straight forward.

I can get DA MB for $20 plus shipping.
QS MB for $100 plus shipping.

I can get this used QS with a dead MB for $100.. but you can get DA's on ebay right now for $150 DONE + shipping?

I am running a B&W @400.. and I dont want the world, but I would like to get to the 733 800mhz G4 level.. Upgrading the G3 is the worst idea as the cpu is $250-$350 and I only have a faster G3.

Any suggestions which way to go here? IS a QS any better for an average user than a DA??

James

I would shoot for at least an 867, for future OSes. Leopard now requires at least an 867MHz G4.

Your B&W is a 400mhz G3, right? I've got a B&W with an 8LR8 500mhz G4 that runs fine. OS X now has enough Altivec in it that the 100mhz boost to 500 G4 is very noticeable and 500mhz G4 ZIFs sell on eBay for around $75 (although usually they're all Sonnets which I have heard sometimes have problems). It doesn't sound like you're ready for Leopard, so a 733 DA would be a lot simpler than modding a QS to a DA motherboard, and anyway, from the looks of Leopard, they say 867 is the minimum, but I doubt it'll be much fun without at least a 1.x Ghz G4, and a G4 at all is probably even questionable. It's probably a major RAM hog as well.

The only difference between a QS and a DA that I've ever seen is simply the CPU speed potentials, but all that's moot with the third party processors available. If I were you I'd go with a DA 733. For one thing, the DA case makes more sense to me than the QS. It's a little easier to deal with. Later on, when prices drop some more, if you want more speed than 733, you could get a third party 1.x Ghz G4 which would be no difference in price for a QS or a DA. One bonus with the QS over the DA is, it probably has a DVD superdrive, but I'll tell you, I've pulled DVD-RWs out of thrown away PC's that are much better than Apple's superdrive and work fine in a G4 using Patchburn. They're even bootable. You're going to need PC133 SDRAM for either, so that's another cost to consider.

The only difference between a QuickSilver and Digital Audio motherboard of which I am aware is that the late model QuickSilver boards can fully address IDE drives larger than 128 GB. Some people say that the QS also had some "bug fixes" and "improved chips" on the board, but I've never noticed a problem with my DAs, and I'm aware of no known issues with the DA motherboard, so I think they're blowing smoke.

I've seen one (only one) assertion (no evidence) that the QS board is slightly faster than the DA board because it consolidated a few ICs, but I've never seen any benchmarks to back up that assertion. In fact, if you put a DA board and QS board side by side, you would be hard pressed to visually identify a difference. The most obvious one is the presence of an extra molex connector for the two pairs of 12 V and ground lines from the PSU, an extra post for the processor daughtercard to connect to, and an extra connector for the heatsink fan to draw its power from.

I'd say that if you aren't buying the second revision of the QuickSilver board or large hard drives aren't an issue for you (maybe you already have a SATA card), then save your money and buy the DA board. On the other hand, having a spare PSU could be handy because these things are expensive, and the fans like to die (one of mine has, anyway, and I know of at least one other person who had PSU fan problems)...

Peace,
Drew

Here is a page about a custom Mac using a QuickSilver CPU with the required 12 V mod. It's really very simple, and $0.10 at the hardware store will buy you all the parts you need.

http://homepage.mac.com/josephk/G4_mod.html

And here is a closeup (from the same page) of the hack.
http://homepage.mac.com/josephk/G4pics/12V_connector.jpg

30 seconds spent with Google would have found this or something like it.

Peace,
Drew

well sorry Drew, I did infact look quite a bit before and after I posted and I have not found the links you provide.

Thanks for you efforts.

James