PlanetZ forums - scopeusers.com

Hi,

Before I begin, believe me I've tried every possible option regarding earthing my system. You are warned this will be kinda long story ( to explain all in full detail ).
But let's start at the begin, When I bought my first CW card ( a PowerSampler hw rev. 1.01 ) I added a breakout box pretty soon. I experienced some noise, but that was not enough to bother me too much. One year later I purchased a Luna ( hw rev 1.01 ) with breakout box. So in total I have 20 analogue I/Os. Not too bad I thought. Please read on.
First I connected the PS breakout box to my Behringer MX2442, no noise at all. Then I connected the I/O from the back of the card, a horrible rumbling sound emerged from my active monitors. I disconnected the card’s backplane I/Os and the noise was gone. Then I connected the other breakout box, pushed all 16 faders up and there was no noise at all. Eureka I thought, until I lowered the first 8 faders of the PS breakout box, there it was again, that annoying, recording ruining noise ! all faders up no noise, some down “Hello noise” It looked like it was canceling itself out at some point ! In the following weeks I've tried all options regarding eathing: one earthed outlet for my computer and the rest of my equipment non earthed ( well it was earthed via the computer ), all equipment earthed via the same outlet in the wall, I shielded the outer mass of the firewire cables from the breakout boxes, I've disconnected the mass of the 16 audiocables (Synapse Platinum by http://www.Belkin.com at $50,- each !) and further all possible combinations which ever you can think of. But after reading my story, I still have hop that someone has the brilliant idea, which will solve my problem and maybe others too.

I have encountered this with Cubase SX as well with Logic Platinum 5.1.3. If you push up the faders all the way and listen carefully then you can even hear the harddrive spin up during the boor sequence while the memory is counted and the harddrives are being detected by the bios, so it's not a software issue I guess. It doesn't matter which I/O box is connected to which card it's all the same, one is fine, but as soon as the second is connected ( even with faders down ) then all hell breaks lose.

I'm a LAN administrator, so I guess I know my way well enough with computers and power currents, but this really beats me.

I'm almost at the point of selling the breakoutboxes, my external FX and my desk so I can make the switch to mixing completely digital with Logic Control !

Sorry, but I forgot to mention that if I connect my active monitors directly to either one of the I/O s there's no noise.

That's why I'm thinkin' about Logic Control.

System configuration:
Asus TUSL2-C, P III 1Ghz, Matrox G400DH, 2 x 40Gb Seagate Baracuda IV, 512Mb Ram, PowerSampler, Luna, 2 x breakout box, Win XP-Pro, SFP 3.1a

Any suggestions ?

Regards
Ronald


<font size=-1>[ This Message was edited by: RoonSmits on 2002-08-16 17:52 ]</font>

It's shot but if you have a 300 watt power you may want to try a bigger one....

don't forget your computer powers those boxes..

a rumbling noise is always a grounding problem.(a good reason for balanced connections,which are easy to lift ground on)

did you try to position the brake out boxes as far from each other as possible (phisicaly) and as far as possible from any other equipment and power connections. does the noise change, when you move the boxes?

or are you running lamps or dimmer close to your equipment or on the same power connection?

did you use symetrical connections? if not, try some di boxes (ground lift).

there are hundred possibilities for your problem. so stay calm and try everything thinkable. what i wrote, helps normaly in many cases. if not, continue posting here.

felix

Hi everyone,

Well I just spend my sunday inside (30°C outside, is this summer finally ?) soldering balanced cables, of which I lifted the ground. This makes a hell of a difference, sooooooh much better than unballanced with ground lifted like I had before. The noise isn't gone, but when I push up all faders, it still adds static to the noise which the desk has of itself, but compared to what I had, it's of a tolerable level.

On the otherhand the I/Os at the back of the cards are pretty persistent regarding noise. They keep humming. I'll see what a DI box ( like the one form Behringer ? ) can do.

Thanks for the advice guys.
Ronald

<font size=-1>[ This Message was edited by: RoonSmits on 2002-08-18 17:18 ]</font>

I've tried everything you tried and then some. In fact, I've tried so many things I could write a book.

So instead of telling what didn't work, I'll simply tell what did!

Here's how I cured the problem:

I replaced my Pulsar Classic with a Pulsar Z-Link board and connected my A16 Ultra to the Z-Link I/O's. This one thing reduced the noise to almost nothing. Then I installed two Ebtech hum eliminators (one on the analog output, one on the analog input). These things reduced the hum and noise to almost nothing (still there but at a very low level).

The side benefit to this is that the Z-Link option seems to sound better to my ears. I can't really explain why, but the sound seems a little more detailed and focused. The ADAT I/O's had a broader, less focused sound quality - not necessarily bad, just different. I much prefer the Z-Link option and wished I had purchased that version initially.

ADAT will sound different due to clock jitter (especially if you were slaving your system, to eg: a DAT player or a preamp or cheaper FX box). The Zlink, while also being 96khz capable, carries the clock better in a CW system - at least, this is what my ears tell me.