Drive seek interfering with mics?

[joe.cavers]

Hey guys,

So I did a recording session a few weeks back with piano and some marimba style vibes, just a few mics, Digi 002, PT LE 7.4, fairly simple.

When we listened back to the recordings, there's a hissing sound that comes in and out, totally randomly. I couldn't work out at all where this could've come from, the room was totally silent. Also, when we did things like fades, the hissing sounded like it was at a different level to the piano. This led me to think that somehow my hardware had created this hissing on the session.

We noticed the other day that when my hard drive is seeking, it added a hissing to the speakers (this wasn't in a recording session, simply in my friends house). Has anyone encountered this before?

I'm using an OWC Mercury on the Go, 7200rpm, 200gb drive. If this is interfering with recordings I'm going to be gutted, that drive is incredibly useful.

Anything I'm missing?

Cheers
JC

[sunburst79]

You need to verify that the hissing you heard in the speakers is making it into a session. If thats the case the next step would be to determine if the the drive has that effect with any computer or just your specific machine. Another step would be to determine if another drive does the same thing with your particular machine.

It could be the actual HDD motor, controller board etc. It could be the bridge board inside the external HDD case, It could be a external drive PSU if your using one. It could be a electrical problem with the actual wall outlets like a ground loop or other interference, It could be poor power regulation or noise on the the computers bus.

[stmclain]

This happened to me once several years ago, fortunately just demoing some of my own material, so not critical recordings.

I never did any trouble shooting, since it was just a makeshift studio I set up in a vocal booth for a few days, but it was definitely related to hard drive activity. I actually think it was happening during writing, not seeking.

I was using a Firewire 410 with an old G4 Powerbook. That meant I had to daisy chain the interface and hard drive, which very well may have contributed to the problem. All the gear was in close proximity to each other. Hard drives do emit radio frequencies, and I always figured this could be the problem, much like when a cell phone rings into an audio system.

And, yes, it does go to tape (I mean disk).

How close was the hard drive to the preamp?