[Hedi]

Hi,
I just received my "Koma Field Kit".
Before I connect anything, I plug it into the monitor speaker via the "Master" output. I have constant background noise. I don't think it's due to my listening setup.
 Can you tell me what it is? Please . And how to solve this?

Thanks.

[Hedi]

Since no one answers my question, I have to make my own conclusion.
Thanks to Koma Electronik for their support.

[chrisi]

Hey! The Field Kit is likely not the most noise-free device out there, in big part this is due to the high amounts of amplification available from the 'GAIN'-setting. Every Field Kit mixer channel has an input gain of x1000. This is necessary to amplify low-amplitude signals like the pickup coils for example.

The noise floor of a Field Kit mixer channel, using professional line level signal as the reference (+4 dBu / ~3.5V peak to peak), is down ~60dB. With full 6.5Vpp signal as the reference level, this translates down to -65dB. This is of course far from todays digital -100dB noise floors but that's also not we are trying to compete with.

You can compare the noise/hiss you are experiencing with the aforementioned numbers if you have access to a DAW with some sort of a Spectrum Analyzer utility. If the noise floor is around the aforementioned numbers, there's nothing wrong with your device! Also, don't get confused with dBFS / dBU.

In any normal condition / use case the noise is not perceivable if any wanted signal is present at any given time. Also, proper gaining really helps.

I hope this answer cleared out some things!

[Hedi]

Hi, Your answer is quite clear. It remains to find a way to get the most out of this machine.

Thank you so much.

[jonheal]

Hi. I just emailed support with what I believe is the same question/issue. The explanation provided by Crisi makes sense, but tell me, does the mixer in the Field Kit amplify far more than the mixer in the Field Kit FX? Because at least in my case, the Field Kit FX is markedly quieter than the mixer in the Field Kit.

EDIT: I will add that adjusting the Gain knobs on the mixer has little to no effect on this background noise. It's pretty much the same volume whether the GAIN knob is set to 0 or 100%. If a slider is up, it's noisy.

[Jackieflipflop]

Hello there!
Noise is a audio system is always present, regardless of the circumstance or the device generating it.
for this reason, noise has to be related to the signal/audio passing through it (signal to noise ratio).

In other terms, if a noise floor gets amplified lots of times, it become surely audible, but probably all that gain is not necessary if the signal is already loud enough and doesn't need all that amplification. So we can't tell if there is too much/less amplification if we don't consider the actual signal to be heard.

It becomes an issue when after amplification, the audio signal is low compared to the noise and this last one is audible.

Measuring the signal-to-noise ratio can be too much of a job, but you can compare the two devices by gain staging them correctly (i.e. avoid amplification, then attenuation and then amplification again) and setting them at the same output level by ear.

In this case, you can tell if the device is too noisy for the signal you pass through it or for your application (for example, a very quiet signal like the one of a microphone needs lots of gain, therefore exists extra clean preamps for that purpose).