828 MKii input from 2 PC's via FW 400?

[metalmike]

Hi,

I know that you can chain the FW 400 ports but I am looking for a way to clean up some noise I have (sounds like bad ground) the cheapest way. Currently my 828 Mkii is connected via FW400 to my DAW desktop and output to M-Audio BX8a's via 1/4". My main desktop goes to the M-Audios via 1/8" stereo to a pair of male XLR's (Hosa cable). I have been having an electrical hum for a long time and would like to finally eliminate it. I think it's due to going from stereo out of mobo to a powered set of monitors.

My options I think are:
1) find some form of impedance connector to go from female XLR to male XLR that would go between speakers and xlr cable if such a beast exists for short money (a decent unit preferred)
2) FW400 cable from 1394 port on back of PC into 2nd FW port on MOTU 828 Mkii but the only issue I can see with this is if I fire up the DAW while main desktop (on 24x7) which may/could cause issues?

Is it possible to run 2 PC's jointly with FW400 into the 828 Mkii I guess is the big question. If not, options?

Thanks,

Mike

[HCMarkus]

Is it possible to run 2 PC's jointly with FW400 into the 828 Mkii

I'd be shocked, and so would your 828 most likely. Just say no.

Find some form of impedance connector for short money (a decent unit preferred)

Lots of "Hum Eliminators" out there… place the unit in between 1/8" and XLRs.
http://www.parts-express.com/cat/isolat ... nators/353

This one is really cheap, and would be plug and play for you:
http://www.parts-express.com/axxess-agl ... r--266-009

And use balanced 1/4" from your 828 to the speakers.

[mikehalloran]

And use balanced 1/4" from your 828 to the speakers.

If your active speakers cannot accept a balanced input, there are many that do.

Passive speakers do not so the lines into your amp should.

[metalmike]

I may connect the MOTU to my main desktop this weekend once I find the drivers I have on the other box (Win 7 64 home premium). But again, this is for the system with the 1/8" to male XLR stereo Hosa cable which has the noise issue. If I can just turn off the MOTU, unplug from the PC end and connect to the other PC and turn MOTU back on that could work, I just want to see if that eliminates the noise by switching over to it. I will be checking other stuff inside the case this weekend as I am replacing a couple of case fans and will check where they are plugged into on the mobo.

The DAW system has no noise at all and it's FW 400 to MOTU and 1/4" into the BX8a's. Not sure if they are balanced cables or not, but again, noise is not the issue on the DAW, it's my main workhorse on 24x7.

Mike

[HCMarkus]

Another approach:
Run the 1/8" line out from your studio into a pair of inputs on the 828 and route the audio to your monitors that way. The 828 will run in standalone mode if your DAW isn't on.

Also, feed AC to all devices from a single wall outlet/power strip to avoid ground loops. You can try lifting the ground on devices as well.

[metalmike]

Hmm I may actually have a set of cables to do that (may not be balanced (TS/TSR's) but let me look into that this weekend. Would I need to load the CueMix or other software? Guess I'll find out this weekend. It'd also save me having to locate the FW drivers I have on the DAW. I believe both my desktop and BX8a's are running into my Furman power conditioner which unfortunately also connects to an extension (with breaker) since it's too far from any wall outlet to reach itself. I'll post back later if things go for the better

Thanks! I didn't even think of that!

[edit] Hmm, I hear nothing out but playing test tone I did see one bar show up but nothing heard from the speakers. I went 1/8 to stereo 1/4" cable. Not sure if the 1/8 is stereo or not though... Time to look in the manual I guess!

[edit #2] I had to crank up the gain to -6db (like channels 1/2 which are my M50 synth input to the Motu/DAW inputs. Not sure why it's so low now. Even had to crank up system volume and speaker output volume knobs. Any ideas? I'd like to have it they way it was (loud when I cranked system volume up (currently @ 62%, normally with direct from PC to BX8a's I would run normally around 20% volume level with speakers set about mid-range on their output knobs...

Mike

[metalmike]

Got things straightened out last night with some input from a couple friends on connections. Ended up going 1/8" to stereo 1/4" from main desktop to channels 3/4 on input to Motu. Then set Mix1 channels 1-4 to levels, etc..then I also changed my mic/headset input to go from my logitech keyboard and noise stopped....impedance or something causing issue. So this morning I set Mix2 for channels 3/4 and tweaked things a tad for it and now I think I am done. Just some minor adjustments between the Mix1 and Mix2 settings so volume is more balanced between the two systems and I'll be good to go! Thanks for the input though! At least I didn't blow any cash on something I didn't need!

Mike

[HCMarkus]

I didn't blow any cash on something I didn't need!

Mike

Nice to find the fix was already there in the tool box. Bravo!