Subject:nasty recording issue

Posted by: ohmaya

Date:5/4/2006 5:12:58 PM

I have a really fast, rock solid PC with Delta 410 soundcard and a laptop with Audigy 2 soundcard. When I tried to record my external synth as straight audio into ACID 6 using the soundcard inputs on both machines. I had the WORST low frequency hum I have ever heard when I arm the tracks to record . The guy at the local Guitar Center suggested I take my grounded three prong plugs on the laptop and the PC and put use a $.69 converter that makes it a two prong shielded plug.

Wouldn't you know, it worked perfectly on the laptop - nasty hum gone. But when I put the synth outpus into the inputs on the PC's Delta 410 soundcard, ground hum is still there, nasty as ever when I arm the audio track for record in ACID 6.

This really hurts, because it also happens with my electirc violin on the PC, which is powered on 9V battery, not AC like the synth. It really killing my ability to record audio in to A6. I cant figure out why his solution would work on one machine and not the other, especially since they are in the same room and AC circuit.

Just one of those things I thought I would throw out there and see if any of you guys have any thoughts...

Subject:RE: nasty recording issue

Reply by: nlamartina

Date:5/4/2006 5:48:05 PM

That's probably a ground loop you hear, and unfortunately there's no software issue that you can fix to make it go away. It's a hardware problem, completely separate from ACID. Can you detail this setup more? You have the synth plugged into both cards? Are you recording both simultaneously? What kind of cables are you using? Are they balanced or unbalanced? How long are they?

The grounding adapter you bought is a quick fix, but it's also dangerous. If something goes wrong, the ground is the first and only place electricity is supposed to run off to. By lifting the ground, you're basically asking for trouble.

- Nick

Subject:RE: nasty recording issue

Reply by: Iacobus

Date:5/5/2006 2:44:44 PM

Would a UPS help (like those from APC)? I know they correct low voltages, spikes and whatnot, but I don't know about ground loops.

(I'm just a musician here.) ;)

Iacobus

Subject:RE: nasty recording issue

Reply by: drbam

Date:5/5/2006 3:21:27 PM

Just some things to check out:
Are you using balanced cables from the synth into the soundcard? Since it happened on both systems it may be a ground problem in the synth. Remove the ground lift and try running the laptop from the battery instead of AC. Also try using a different AC circuit and make sure to use a good power conditioner.

drbam

Subject:RE: nasty recording issue

Reply by: randygo

Date:5/5/2006 3:56:01 PM

Here's an article that may help. An audio isolation transformer is always a good investment.

http://www.discmakers.com/music/pse/techbuzz.asp

Cheers,

Randy