Where's This Hiss Coming From?

[Orange Worker]

I'm getting an annoying hiss when i record audio, and I'm not sure where it is coming from. For a while I thought it was from the room, mic, cables, or I thought something was wrong with my pre, but I don't believe it is any of this, especially after tonight. Tonight I recorded some audio, but I accidentally had the wrong channel assigned, so their was no sound coming from any source - and I still got the noise. When I record enabled the track, I also heard the noise, while still on the wrong channel. So, when I record acoustic guitar through my great river pre (at a high gain) and work with the L1 and Sony Oxford on my master, the noise is increased even more and is unacceptable to me, it sucks!! In Pro Tools, the noise reads just about at the 4th line from the bottom (on the meter). Anyone know how I can control or eliminate this problem? I'm using the 001 and PTLE 6.4 on a PC.

Thanks.

[Rail Jon Rogut]

So you're saying with your Great River preamp feeding into a LINE INPUT on your 002 (Input 7 for example).. you have a high noise level?

If you assign the input to a mic input without a load -- it's expected to have a high noise floor.

What happens if you feed the output of the Great River preamp directly into your monitor system... bypassing the 001?

Rail

[Orange Worker]

Thanks for your reply Rail. I'm not sure what you mean by, "If you assign the input to a mic input without a load -- it's expected to have a high noise floor."

But I am getting the noise when going from my GR into the Mytek stereo 96 into the 001 - throught the SPDIF input.

I'm going to try feeding the output of the GR into my monitor, give me a min.

Henry

[Orange Worker]

OK, feeding the output of the GR directly into my monitor, I heard very little hiss - I had to put my ear against the monitor, but it's there, seems normal to me. I used an SM57 with the gain at 50db and the output level set at 5 o'clock on the GR.

Is it normal to hear noise on a record enabled audio track in PT, without having the correct channel assigned to the source?

[Rail Jon Rogut]

If you have the input without anything feeding it (without a load).. you should expect a high noise floor.

In your case you're talking about a digital signal -- white noise on a digital signal indicates a bad clock source. What's your clock settings on your digital source set to.. and is Pro Tools set to the correct clock source for the S/PDIF port you're using? Are you using a high quality 75 Ohm digital S/PDIF cable?

Rail

[Orange Worker]

rail,

i have the clock set to spdif. i believe their are a few choices - spdif, internal, and optical?

[Rail Jon Rogut]

And the Mytek? Do the sample rates match? When Pro Tools is set to S/PDIF it's getting it's clock from the digital source so the Mytek must be on internal and set to the same sample rate as the Pro Tools session.

The options are S/PDIF RCA or S/PDIF Optical BTW.

Rail

[Orange Worker]

i'm not sure how to set the mytek to internal, but the sample rates match - 24 bit / 44.1

[Rail Jon Rogut]

I would suggest you feed the Great River preamp output via analog into the 001 input 7 and tell us what it sounds like. Put Pro Tools on INTERNAL.

Rail

[Orange Worker]

OK, i'm going to give that a try sometime today, but i'm exhausted now. please come back and check later on today. thanks for your help.

henry