Noise Gate/Expander block....clarification please...

[The_Kid]

So, I've always had this noisy type hiss going on my patches (see my other insanely long thread trying to figure it out)......I recently tried adding the noise gate/expander block after the amp block and it's really cleaned it up.

What I wanna learn more about is the sidechain aspect....as well as why its going so much more after the amp block than the gate at the beginning? I understand that moving the block after the amp, will remove any amp hiss that is generated.....and I've experienced that with my ISP rack noise gate I had when I had my tube amp...as it ran before preamp, as well as in the loop...so I get that. And I know gain creates hiss....but I'm getting it on a blues junior mid gain type sound...and if I barely touch the string to the fret enough to sound the note, the hiss comes through louder than the note at times...


So I'm fine with adding the gate/expander block....I just want to better understand it...cause its the first time I've used it since I had the unit. Can someone explain the sidechain parameter...and where it should be placed in relation to what it is 'gating'?


Also....lol, please correct any misunderstanding I have here....please.

 

[xrist04]

The sidechain input allows you to control the triggering of the noise-reduction effect.

Normally, a noisegate's detection circuit uses a copy of the input signal to check whether it exceeds the threshold level or not. If the noisegate has a sidechain input, you can use a different signal to control the gate. The most common way to use the sidechain is use an EQ to pick out the specific frequency that will open (or close) the gate. You could use the EQ to select only LF and midrange content, for example, if you want to gate out some hiss.

More info: Noise gates < Dynamics processors < Pro-Audio Basics


Geek info: Cliff has written previously that the noisegate in the Axe-Fx is technically a downward expander.

 

[The_Kid]

Right, I remember reading that about the downward expander type thing...and I think the ISP Decimator works in the same fashion....I had great results with that. Does the gate block work differently than the input one in the GEN 1 Ultra?

So I kinda get what your saying about the sidechain thing...where would it go in the 'chain' then? in series right after the effect? parallel to it? Parallel right after it? if I'm' correct it allows you to choose which row to use as a side chain.....if I run my routing off of row 2, I'm assuming I would choose row 2?