interference noise? hard-drive blips? earth? help! (same post as in "so much gear")

[matt thomas]

Apologies for double posting in "so little time" thread and here but I couldn't decide which one. Perhaps if you have any answers you could answer in the other version of this post?

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Hi

Since setting up my new space I'm getting some weird noises coming through my system.

- I can hear every click, blip and pop from my hard drive coming through my speakers

- There is a background hum/buzz that disappears when I move my mouse but comes back when I stop moving it. Sometimes this is vice versa (sound only on moving mouse)

- I have unplugged everything except my mixer (mackie digital x bus), my computer (pc with Lynx 2c connected to mixer by AES/EBU i/o only), and my amplifier and speakers, creek (unbalanced) (connected to main analog outs on mixer (balanced I think)) and ns-10's. It think the problem remains when taking the mixer out of the equation.

- I emailed Lynx, they offered some support, but haven't replied since I found the problem to be earth related. When I lift the earth on the computer the symptoms all go away.

- All 3 powered items are plugged into the same socket

- the amplifier has these weird old style five pin plugs, I have to use a couple of plug converters to connect to it, I wonder if the problem is related to the fact that the mixer is balanced out and the amp is unbalanced in and I'm losing something in the connections, I only use it because it is a nice sounding amp. i don't have another handy to try.

- (afterthought) Oh, and the building we're in blows lightbulbs all the time, they only last a couple of weeks each.. hmmm..

Would anyone have any suggestions as to what could be causing this and how to get rid of it?

thanks for your time
narco

[Geoff_T]

Originally Posted by narco

Apologies for double posting in "so little time" thread and here but I couldn't decide which one. Perhaps if you have any answers you could answer in the other version of this post?

-------------

Hi

Since setting up my new space I'm getting some weird noises coming through my system.

- I can hear every click, blip and pop from my hard drive coming through my speakers

- There is a background hum/buzz that disappears when I move my mouse but comes back when I stop moving it. Sometimes this is vice versa (sound only on moving mouse)

- I have unplugged everything except my mixer (mackie digital x bus), my computer (pc with Lynx 2c connected to mixer by AES/EBU i/o only), and my amplifier and speakers, creek (unbalanced) (connected to main analog outs on mixer (balanced I think)) and ns-10's. It think the problem remains when taking the mixer out of the equation.

- I emailed Lynx, they offered some support, but haven't replied since I found the problem to be earth related. When I lift the earth on the computer the symptoms all go away.

- All 3 powered items are plugged into the same socket

- the amplifier has these weird old style five pin plugs, I have to use a couple of plug converters to connect to it, I wonder if the problem is related to the fact that the mixer is balanced out and the amp is unbalanced in and I'm losing something in the connections, I only use it because it is a nice sounding amp. i don't have another handy to try.

- (afterthought) Oh, and the building we're in blows lightbulbs all the time, they only last a couple of weeks each.. hmmm..

Would anyone have any suggestions as to what could be causing this and how to get rid of it?

thanks for your time
narco

Hi

It's hard to know, not being there, but you may have raised the point at the end where you have a balanced signal driving an unbalanced amplifier. You can bet that the mixer is not transformer balanced so you are shorting one side of the output to ground, it appears. I suggest a phone call to Mackie to see if the mixer is happy with this arrangement.

I don't think the lamp blowing issue is related to your immediate issue but it implies that you might want to incorporate some surge suppression or a good UPS into your set up.

Then, just 'cos it's a 3 pin socket, doesn't mean there's a ground on it. I've been to installations where there was only two wires to the power outlet.

I think that you just need to review everything, particularly your interconnecting cables, and take it from there.

[shaddai]

I've had this problem before & it's really aggravating. Any mouse move goes BBZZZZ in the monitors..then you stop, back up some & listen to the section again to be sure it's not in the audio..this time remembering to not touch the mouse again...just to notice HD access racket in the audio....back up, listen again to see if the noise changes... if it does, it's nothing to worry about. If it doesn't, then it's possible it's in the audio file & you have no way to tell other than to burn a CD & get it in the car...

I see 2 issues that are the same as what was going on when I had the problem:

1.) Mackie power supply with a DAW power supply on the same circuit.
2.) Mackie mixer driving an unbalanced amp.

Dunno if it's 100% possible, but it makes sense to my feeble mind that if the mackie PS is dumping a weee bit of noise back into the AC line, then there's no reason why the DAW PS couldn't inject it into the mobo...where a mouse movement could modulate it. The unbalanced amp has already been talked about.

Just to confuse things some more, I did manage to fix it misadvertantly. Due to wanting to run newer DDR memory, I swapped mobo's ...and what do you know...the noise vanished and I have noooo clue why.

Dunno if it helps, but should give some info to think about.

Todd

[matt thomas]

thanks, definitely something to think about, I think I'll track down an amp with balanced in's and see what happens..

any other thoughts would be apperciated too!

thanks
narco

[knollr]

One cheap fix you can try. You really only want to have one ground point for your system, be it audio or power. Lift the ground on everything but one unit and try dfferent units. Also, check your phasing if you are using ground lifts. Thirdy, check for fridges or anything with a compressor on it. They are awful for sending crap through the lines.

Good Luck!

[Flora]

i just solved this problem for myself by putting a ground lift on my cpu

[Wavebourn]

Originally Posted by Flora

i just solved this problem for myself by putting a ground lift on my cpu

I solve similar problem every time I record live concert on notebook: I unplug it from power outlet and let it run on batteries.