Strange recording thing

[ellaguru]

hi
i recently bought an old recorder: the philips d6350.
http://commons.wikimedia.org/wiki/File:PhilIPS_D6350.jpg
the strange thing i noticed is that when i record straight into it with the sp-303 i have a right clear recording, when i record straight or with the computer into the philips there is always a hi-noise very distrurbing. last day i recorded only with the sp-303 and i noticed that if the computer was On, the noise appeared in the recording session. but in this case i put the pc to off, and that's all.
if i want to record from the computer there is always this noise.
maybe it's a sort of mass-electric thing...
have you got some suggestion to make this thing disappear?
thanx

ps
curious & ironic thing: in the front of the recorder it's marked: "computer compatible"

[cartesia]

sounds like it is to do with the grounding of your computer..

I get this (only when all my gear is arranged in a certain way.. ) - Luckily I have a laptop so I can pull the power cord out while I record.. bingo, no buzz.

Also if you use an external audio interface, try running it off wall power instead of bus power (if it normally powers off the computer).. I've noticed with some arrangements of gear again, that this eliminates some noise.

Also, are you actually using a non-standard audio interface? The onboard ones do not have great quality.

Would you say the noise is more like 'noise'/hiss, or a hum/buzz? (and if so. . would you say it's high pitch? or low?)

[ellaguru]

thanx cartesia.
i forget to say that i got a laptop too. until now i tried directly from the headphone output of the pc. i don't still tried with the m-audio interface.
anyway, even when the pc is not connected directly with the sp-303 (or the philips) there is always this noise in the recording.
maybe if i try to change some electrical things (socket positions) or i use pc with his own batteries, it will change something...another solution is the audio interface.
sorry for my english, but what do yuo mean exactly when you say "so I can pull the power cord out while I record.. bingo, no buzz." pull out means what?...sorry...

[Les Braun]

thanx cartesia.
i forget to say that i got a laptop too. until now i tried directly from the headphone output of the pc. i don't still tried with the m-audio interface.
anyway, even when the pc is not connected directly with the sp-303 (or the philips) there is always this noise in the recording.
maybe if i try to change some electrical things (socket positions) or i use pc with his own batteries, it will change something...another solution is the audio interface.
sorry for my english, but what do yuo mean exactly when you say "so I can pull the power cord out while I record.. bingo, no buzz." pull out means what?...sorry...

Yo ella
I get that too with my turntable. I think it has something to do with the arrangement, but I tried rearranging and the buzzing doesn't go away. I think it might have to do with my step-down converter.
And btw, with "pull out" he either means "dilungare", or "strappare", I think...

[hurlingdervish]

yea that buzz is annoying...

laptops arent constructed very well. thats why i bought a double battery so i can stay unplugged for longer, works quite nice though the batteries bigger than normal

[Nation]

Half of the problems you guys are speaking of are caused by ground loops. These problems can easily be found and eliminated by using a 3 prong to 2 prong convertor on your external power supplies.

HD,

You have an HP pavilion like me, and mine has had this problem whenever I plug in the power supply. I use a 99 cent 3->2 prong converter from Home Depot and it eliminates the ground hum every time.

[PHeMoX]

Yeah, also when it comes to desktop PC's investing an additional or external soundcard might solve the issue as well. Be careful though, some soundcards or even some monitors have a tendency to pick up radio sounds.

[hurlingdervish]

Half of the problems you guys are speaking of are caused by ground loops. These problems can easily be found and eliminated by using a 3 prong to 2 prong convertor on your external power supplies.

HD,

You have an HP pavilion like me, and mine has had this problem whenever I plug in the power supply. I use a 99 cent 3->2 prong converter from Home Depot and it eliminates the ground hum every time.

will do!

[ellaguru]

thanx cartesia.
i forget to say that i got a laptop too. until now i tried directly from the headphone output of the pc. i don't still tried with the m-audio interface.
anyway, even when the pc is not connected directly with the sp-303 (or the philips) there is always this noise in the recording.
maybe if i try to change some electrical things (socket positions) or i use pc with his own batteries, it will change something...another solution is the audio interface.
sorry for my english, but what do yuo mean exactly when you say "so I can pull the power cord out while I record.. bingo, no buzz." pull out means what?...sorry...

Yo ella
I get that too with my turntable. I think it has something to do with the arrangement, but I tried rearranging and the buzzing doesn't go away. I think it might have to do with my step-down converter.
And btw, with "pull out" he either means "dilungare", or "strappare", I think...

thanx computers, but i think it means "estrarre" (to extract) or something. anyway this is what google says ....

@Nation
i use 2 electrical extension cords connected each other, maybe that's the trouble. what i don't undestand is the fact that even when the recorder and the pc aren't directly (or undirectly) connected, this problem is there.
...ah, the electrical basis...

[Nation]

If the problem you have is from a ground loop then the frequency content of the noise will have harmonics of 50,100,150...200Hz. Here in the US it is 60,120,180...Hz. Try running both devices off of battery and see if it changes the problem.