Helix processor connected to AV receiver makes crackling sound

Question

My setup looks like this: Guitar goes to Line6 Helix, amp and cab sim there, output goes to AV receiver via either analog or digital input.

The problem is, when the simulated amp is really loud, helix global volume is loud, and/or I hit the string hard, especially the initial attack, I hear crackling sound from the speaker connected to receiver, although the sound volume is not that high at all.

When I reduce the volume on Helix and increase it on the receiver, it seems to remedy the problem. But, if possible I'd like not to change the receiver volume, because other sources such as PC via optical cable, HDMI ARC and so on are more or less matched to the desired final volume level.

So, my question is - I assume the cracking I hear means the source volume is too high. Can I do something about it, except for obvious things like playing quieter, preferrably without increasing volume on receiver?

Answer 1

Answering to summarize the discussion:

The high output level overdrives the input on the receiver. Hi-fi amplifiers aren't designed to be overdriven, so instead of nice distortion you get the crackling sound. Turning down the volume at Helix helps, because the lower output level doesn't overdrive the amp. Additional detail is that Aux inputs are designed for 10dB lower level than regular line input, and the Helix was plugged into Aux instead of line level input.

If you want the Helix to send similar output to other sources, add a compressor after the cabinet model. When it is set up correctly (which is an art in itself), it will clip the peaks and boost quiet parts without changing tone too much. Almost all music that you hear has some degree of dynamic compression.

Answer 2

The problem was using AUX input instead of regular analog input. As mentioned in the other answer and comments, it seems to expect lower input level, thus signal from Helix causes overdrive.