PlanetZ forums - scopeusers.com

Ppl when i raise my master fader up to 127 (MAX Vol) and connect the analog source (without anything plug to it) and raise the analog source channel vol to maximum i have a lot of noise,its happening only with analog source the digital sources are Ok why is that ???

It's natural.You're just hearing the noise of analogue circuitry.

ok man thx

well, the presence of noise is natural, but not the level on the screenshot.
Even if you cannot 'correctly' measure an open analog input, the noise should be more in the range around -80db.

Is there a pattern in the noise ? like a constant hum, sizzling ?
then the PSU could emit disturbance frequencies or the chassis of the PC is not grounded.

does it change when a pull-down menu is displayed, mouse pointer or windows are moved ?
then it's most likely 'software' based, often by shared interupts

cheers, Tom

The pre-amps on the Analog input are limited in fidelity and are located in an electronical noisy environment known as your computer. But -60dB seems a bit heavy, I agree.

yes you right the noise is stand on -85db

yes you right the noise is stand on -85db
and the noise soundin like pink noise
when i move the mouse or something like that nothing happening the noise is constant
So i understand from this that the analog gear have about 85 db sifgnal to noise ratio,right ?
So the best way to record is with digital inputs ?

Yes, you are right. Especially the unbalanced inputs are prone to low noise floor. If you want pro specs you should use the digital inputs (SPDIF, Z-link, ADAT etc.), with sufficient analog outboard.

ok thx

-85 db is perfectly ok for that input stage and if it's pink noise that's even better (no bad ground hum)
don't forget that a lot of gear doesn't even show the signal on an 'open' input.
they sense that there's no plug inserted and simply mute it... then you read '...wow, not the slightest amount of noise at the inputs...' in reviews.
(-85 is about 10times better than what a perfect(!) vinyl disk on an exclusive player could deliver - to give this some real context )

cheers, Tom

exactly.

Paralon wrote:when i move the mouse or something like that nothing happening the noise is constant

Paralon,

Tried a PS/2-Mouse instead of USB?

aaah, damn, overread that you said nothing happens to the noise flor when moving the mouse...

nevertheless a good advice to save some resources...

cheerz
roman

thank you all