"noisy" firebox?

[vitaly]

Hello,

I hear not very loud but pretty much audible high frequency background noise in the firebox headphone output. No mics are connected yet and channel 1,2 level knobs are all the way down. The noise appears on my recording in Cubase as well.
Is possible to record a *dead* silence with a firebox or I need to use more expensive equipment?

Thanks,
Vitaly.

 

[altiris]

Are you using CRT monitors? turn your PC monitor off to see if it is causing the noise.

 

[vitaly]

No, I have LCD, btw I hear the noise even when the firebox is not connected to PC yet (if I plug an external power only). Actually it's my second firebox. The previous had the same problem I contacted with presonus support and they recommended to exchange it. I did but a new one still has the same issue. Maybe I just want too much from $299 unit?

 

[dgatwood]

No, I have LCD, btw I hear the noise even when the firebox is not connected to PC yet (if I plug an external power only). Actually it's my second firebox. The previous had the same problem I contacted with presonus support and they recommended to exchange it. I did but a new one still has the same issue. Maybe I just want too much from $299 unit?

Does it get louder when you play a recording, or is it just continuous? My guess would probably be that the headphone amp just sucks. Do you really expect them to do more than just throw a 5W 741 in there? I think the assumption is that you'll use monitors if you care about a low noise floor....

That said, if it really is in the recording, that's a different matter, and could point to a poor power supply in your computer (producing noise on the FireWire line) or in the FireBox. If so, you might try what I did to silence the CPU/GPU chatter in my FireWire 1814. I think the term is ground bussing.

1. Pick a sacrificial input or output (i.e. pick one and decide that you just won't use that one for now).
2. Buy yourself an appropriate audio connector---probably a stereo 1/4", but it depends on which jack you choose.
3. Buy yourself a power plug that plugs into your wall outlet.
4. Buy yourself a spool of 14 AWG hook-up wire.
5. Buy yourself a spade connector (a connector that a wire shoves into that you can, in turn, shove under a screw and screw it down).
6. Cut off a length of wire that is long enough to run from your computer to the audio interface. Cut a second one that is long enough to run from the audio interface to your wall outlet.
7. Solder one end of the first wire to the ground contact on the audio plug.
8. Solder the other end to the space connector.
9. Remove a grounded case screw on your computer, shove the space under it, and replace the screw.
10. Solder one end of the second wire to the ground contact on the audio plug.
11. Solder the other end of the second wire to the GROUND contact on the electrical plug. Be absolutely certain you don't screw that up!
12. Electric tape the hell out of the connection so that if it jumps loose, you can't possibly get 110VAC dumped into your ground wire.
13. Plug the audio connector into the audio interface.
14. Plug the power plug into the wall.

 

[vitaly]

The problem that the noise is on the recording which is very sad...
14 step instruction sounds cool, I'll definitely try it.

Thanks a lot,
Vitaly.

 

[Monkey Allen]

I have a Firebox too and haven't had this problem. The only time I get noise is if the gain is up around 9 or 10 for my condenser mic.

The easy answer would be that you got dudded twice...but you'd have to think the chances of that are pretty remote