MIDI output sound gremlins

[FRENCH396]

I use an m-Audio Keystation 49e to input notes into my Powerbook G3 running Reason 2.5. It puts out some outstandingly realistic sounds - pianos, guitars, drum - everything ! It's my first excursion into MIDI.

I run a line from my computer speaker output jack into the "Line In" sockets in a Roland BR8 recording deck (the cord is like the line out cord from a portable CD player).

As I play the notes I get an weird sound in the background - it's a faint buzzing, phased kind of sound - like the sound you get tuning an old fashioned AM radio. It's not a power hum - it's like a wavering sound.

I only get it when I hit a note. It's totally quiet when I let off the key. It's destroying my recording efforts ! The folks from m-Audio tried to tell me that it's some kind of ground loop or power source problem. I tried lots of different configurations... that's not it. Help ! I've got all this expensive equipment and I can't get a decent recording !

 

[James Argo]

I run a line from my computer speaker output jack into the "Line In" sockets in a Roland BR8 recording deck (the cord is like the line out cord from a portable CD player).

I suspect this is where it all begins. Please use Line out instead of speaker out.

What's the different, Jaymz?

Line out is rather plain (cleaner) un-amplified signal. Speaker out in the other hand means "signal routed from this output jack is amplified to feed your speaker". Sometime it's not compatible (gain wise) with your recording level requirement to get clean sound. In some circumtances, the sound might get distorted if the signal is too hot.

But signal from line out is too quite Jaymz. What should I do then?

Use pre-amp (or even your small mixer) to make up the gain. This is way better than using Speaker out. So you're gonna set Line out --> Pre-amp --> Recorder.

Hope it helps.

Jaymz


ps. This thread realy belong to Recording Technic forum rather than MIDI forum I might say

 

[TexRoadkill]

The outputs on soundcards are rarely powered and even then you wouldn't want a preamp. The problem there would be too much gain.

You might try using a different cable. Those thin cheezy cables can pickup interference but usually that is a more constant sound. The fact that it only does it while you are playing would lead me to believe it's something else.

Try plugging some headphones directly into your soundcard and see if the sound is still there. If it is then we have to look at the soundcard as the possible culprit. You could be picking up noise from the computer and cheap soundcard.

 

[FRENCH396]

TO James and Tex...

Thanks for your replies. I found the answer to part of the problem from Roland (I'll post the details below). The other part of the problem - I'll bet you're right: using the headphone jack for line out and using lightweight cables are probably causing the background noise problem.

Unfortunately, the only audio out source on my computer is the headphone jack... Maybe I can find some way to use the USB port and convert it to an analog signal to go clean to my deck... Or invest in some recording software. Thanks again.

Here's what Roland told me:

The audio output from my computer does have a little background noise when I send a note via MIDI (Keystation 49e through a Powerbook with Reason). I don't hear it when I use headphones in the headphones jack, but I get it when I use the head phone jack to send a "line out" to my Roland BR8 digital recording deck.

Here's the solution: the Roland BR8 has a boatload of onboard effects. THere are about 50 presets which use a combination of effects. The default is to have the preset ON. The preset I was using had a combination of compressor, flanger, and digital delay. The effects were "hearing" the background noise and applying all these effects - this is what created the phantom noises. I switched "BYpass" to ON - thus passing all the effects - and the noises disappeared.

- Andy in Maine