Noise when monitoring off the MTR

Not necessarily a problem with NTrack

I’ve just realised that what I thought was noise emanating from my Sansamp GT2 is really noise that’s created after my mixer; when the program material comes out of my computer, there’s a faint crunchiness…particularly in the right channel.

I always thought this was something my Sansamp created, but it’s not. If I monitor directly out of my console, the noise isn’t there–the noise is returning from my computer.

Does anyone know what might be causing this? I’d love to have help sorting it!

My PC has an Asus motherboard and I’m using an Echo Mia soundcard. I used to use a Layla, and the problem occurred back then, too. At the moment my mixer is a Tapco Mix60, but the problem was also present when I used a different mixer.

Is this what’s known as “harmonic distortion”? Are the guts of my computer creating uncorrectable harmonic distortion?

Any help appreciated!


Hi, As its happened with two different sound cards I very much doubt its computer or soundcard related unless its an earth loop problem. What route is the signal taking between your computer and your monitoring speakers?

Try swapping the output jack plugs as they come out of the Mia if the problem changes channels it is the Mia or something earlier in the signal chain, if the problem stays in the same speaker it is being caused by something later in the chain.


switch to internal soundcard - insert blank audio track - arm track for recording (from int card) open recording VU meters - hit LIVE you should now see how much noise your computer is generating (meters show input) - record trak for a couple of minutes - playback will contain recorded noise AND computer generated noise (you get the noise level twice over) -

now switch to your other soundcard and do the same (to a new track) make sure the soundcard has NO inputs plugged in - now you can compare tracks by xooming in to see which one carries the most noise -


DC (DC or ultra-low freqs) and low level ultra-high frequencies can sound like scratchiness when digitized. Sub and ultra harmonics could be getting into the chain somehow.

(I had this happen a long time ago when doing analog multitrack. I wasn’t able to find it until I hooked a scope to the output. I was able to SEE the full range output and calculate that the frequency was in the 125k ballpark. It was the bias from the tape recorder getting into the signal chain because of a bad cap and bad shielding on a insert cable. I also had a power amp that kept blowing tweeters randomly. It sounded scratchy sometimes. It was sending full 400 watts output at about 80k to the tweeters…POOF in seconds when the amp became unstable and when into oscillation.)

Is it really just in one side or is the level simply lower in one side?

Does it happens with all audio formats? It it truly not present at all in a recorded wave file?

Freeze a stereo track that’s been recorded as 16 bits that has NO noise in the track itself. Freeze it as a 32 bit file (in the prefs). Does the noise show up in just one side? Freeze the same 16 bit track to 16 bits. Does the noise show up in that underlying file?

ALSO…change samplerates. Any difference?

Is the noise present in a mixdown when played on someone else’s machine?

Mr Rabbit’s suggestion is a GREAT way to get started. It will help weed out a lot of stuff.

Hey, guys–many thanks for your responses.

I’ve discovered that the problem, at its severest was mostly the result of “thermal creep”–a phenomenon I only learned exists during this past week.

Hopefully I’ll get the time to do a bit more investigating tomorrow.


I haven’t heard that term since 1985 or so.

Quote: (Fuggle_Hop @ Oct. 10 2008, 4:52 PM)

"thermal creep"

Kudzu? :whistle: