Horrible "white noise" in garageband.

[jiant.]

Ok, so I'm trying to add some bass to a recording a friend sent me. I pulled out my bass and ran through some stuff before hooking up my computer and everything was fine, my signal was bass - tuner - Sansamp BDDI - BA115 - headphones. Now the signal is bass - tuner - BDDI - BA115 - Macbook - headphones, with an 1/8" from the headphone out on the BA115 to the input on the mac. When I record with monitor on so that I can hear what I'm playing I get this awful, white noise that at first i thought was hissing or something, so I tried cutting the treble or even turning of my BDDI, but nothing at all helped. Any ideas?

 

[thehurlatron]

I don't know if this is the problem, but I wouldn't run a headphone out to the input of the Mac. Even though it's small, it's still putting out power, this putting power into the input of the Mac. Like I said, I don't know if that's your problem, but it's not a good way to go. Why not take the line out from your sansamp, use a 1/4"-1/8" adapter and do it that way. Then the Mac is just getting a line level signal, and not a powered signal from the headphone out.

 

[Nick Kay]

Are you running the Macbook off of battery power, or is it plugged into the wall? Is the input on the computer a microphone input or a line input? Is the output on the amp a DI, line, or headphone level output?

 

[jiant.]

The Macbook was plugged in, it is a line input, the output on the amp is a headphone amp.

 

[Nick Kay]

Alright, I'm going to highly suggest skipping the amp and just going from the Sansamp's output (set to Line mode). The less circuitry in the way, the less noise you'll get, and it'll be the right impedance for the input on the machine. You can always EQ later on. Take the tuner out of the chain, too. You should be tuned up before you hit record.

It's also possible that the noise is being caused by the machine being plugged in, especially if the power adapter is of the two-prong variety. Some sort of ground issue, since the two-prong adapters don't have a separate ground. Try recording on battery power.

 

[PRESofUNIVERSE]

If your amp has a ground lift make sure you are using that too. I had this happen on a guitar amp while recording, and the amp didn't have a ground lift. In the end, i just mic-ed the amp.

 

[Doc Labyrinth]

Check out the Audio/MIDI setup in your mac's utility folder and make sure that your default input is line in as opposed to the built in mic.

 

[rr5025]

I have the same problem, I just run a 1/4 to 1/8 cord into the line in in the mac. My friend who records on his comp quite a bit said that my problem was it was going from analog to digital. Don't know how correct that is though.

Thanks for the ground tip I'm gonna try that out right now!

 

[tasty sweeps]

i run my bass[es] through my macbook with just an instrument cable with a 1/4-to-1/8th inch adapter on one end. sounds good enough, i almost never have latency issues [ones that effect playing in any way] or unwanted noise. unless of course i've got all kinds of junk open at the same time. the headphone out on the mac goes to my home stereo and that's pretty much my amp.

 

[Marley's Ghost]

It is probably interference from the power adapter on your PC. Try using a ground loop isolator from radio shack on the audio connection.

 

[megadan]

As mentioned, try it right from the Sansamp. That's a better match than a headphone output.