Issue with helix - automatic gain control

[ubuuntu]

I've noticed that on many built-in and some custom presets I get something that sounds like Automatic Gain Control on those old cheap casette players/recorders. Essentially, start with factory preset 10C, then 1) with complete silence on the input, 2) very gently strum a chord 3) then strum hard. Sound level is roughly the same in 1 and 2 and there is a distinct 100-300ms on 3 where level gets "controlled" effectivelly dropping volume.

 

With digital effects and limited dynamic range, it stands to reason you would have some sort of protection from overrange errors / clicks and pops that would result. But I don't think this was done well on Helix - and I don't think AGC is an answer at all (if that's what's happening).

 

So the questions - have you guys noticed this? Is there a better explanation of what I'm hearing? Any suggestions on how to overcome this (other then the obvious - e.g. edit all presets to manually manage volume on every stage in the chain to stay clear of AGC)...

[silverhead]

Perhaps the noise gate settings on the Input block? If not the noise gate perhaps another FX block? Try  bypassing any suspected FX individually until you find the culprit.

[DunedinDragon]

That sounds more to me like a compressor or limiter that may be in the signal chain.  I often do that intentionally so that I get a fuller and more aggressive sound with a hard strum without increasing the volume very much.  On some amp models you'll get that same effect when you dial up the amp gain or the master volume (those that don't default to 10).  it's possible that you could get the initial drop in volume with a high master volume as the additional amp driven distortion effectively lowers the overall output volume  due to the flattening of the peaks off of the signal which your ear perceives as less volume.

[PaulTBaker]

could the amp sag have something to do with this?

[datacommando]

On 10/2/2023 at 11:13 AM, ubuuntu said:

I've noticed that on many built-in and some custom presets I get something that sounds like Automatic Gain Control on those old cheap casette players/recorders.

Hi,

 

As you have noted, this issue is not on all presets, but “on many built-in and some custom presets”. Therefore not auto gain as such.
 

Helix doesn’t have any AGC - best guess is, like others here have commented, probably due to some sort of compression or gating on the signal. Heavy compression can cause that “breathing”, or “pumping” effect.

 

Hope this helps/makes sense.