Inserting effect devices between the guitar and the amp will always add a bit of noise, but this noise can be reduced to almost nothing by carefully adjusting level. If levels are not correctly set, any noise will be increased by the high gain channels because they compress and increase lower signals.
Here are some tips to get rid of the noise on the G-System. They will work well if you have a serial loop in the amp.
1. Press the boost switch to set the levels with max outlevel and switch to the high gain channel.
2. Lower the input level of the guitar. Although the manual recommends to get the higher level as possible in the guitar input, we solved lots of cases by reducing it. as a starting point set the level to 0db, that will give more headroom in adjusting the loops.
3. Adjust the loop level, normally the range will be from 0 to 12 dB.
4. Adjust the preamp/head channel level to get the best return level to the G-System. If there is an overload , the red led will illuminate, even if the green LEDS are not all on. You can also adjust the loop headroom parameter if necessary. That will change the loop return sensitivity.
5. Activate the Noise gate. The G-System Noise Gate is in the same time very efficient and smooth.
6. Do not use the compressor on high gain channels. High gain channel will also compress the signal and the result would be a double compression that could increase floor noise even more.