Helix Volume Knob at 100% (or Disabled) = Crackling?

[wlaycook]

Hi guys,

 

Since I've been using my Helix for the past several months, I've normally set the volume knob to 12 o'clock. However, after learning more about optimizing gain staging, signals, etc., I learned that the large volume knob should be set at 100% (or simply disabled), since that is basically the unadulterated Helix signal at 0.0dB. Note that this is when I'm using my Helix as an audio interface (USB > Mac, and XLRs > two powered JBL monitors).

 

With the volume knob maxed or simply disabled (i.e., at 0.0dB), I have turned down the trim/gain on my monitors to compensate for the actual volume in the room. However, with this new setup, a lot of presets that were otherwise fine are resulting in crackling/artifacts. How is this the case if the volume knob theoretically doesn't impact anything before it (as it relates to potential clipping)?

 

As it stands, I might just go back to using the knob at noon (also was a lot more convenient being able to turn my entire output of the recording setup up/down with that knob instead of via the apps/software or trim levels on the backs of the monitors), but wanted to get your thoughts.

 

Thanks

[rd2rk]

There's two main reasons to max/disable the BIG KNOB.

In this position, the output is at UNITY in relation to the Input.

IOW, turning it DOWN is subtractive.

 

Theoretically, since the level control happens in the digital realm (before the converters), it's possible that there could be a tonal difference, caused by a bunch of technical stuff involving bit depth and whatnot beyond my level of expertise, and only detectable by Steve Vai and your dog. Bottom line for me - if I choose to use the BIG KNOB for level adjustments, I don't hear any difference and, therefore, it doesn't exist in the real world.

 

The other main reason you'd want to disable the BIG KNOB is when sending your signal via XLR to FOH or an external Audio Interface, and monitoring your stage level with an on-stage amp. In this case you would disable the BIG KNOB for the XLR outs in order to send a steady signal to FOH, while still being able to use the BIG KNOB to control your stage level through your amp.

 

A third reason is that if you're setting the output levels of your presets with the BIG KNOB at less than UNITY, when you up it to UNITY you'll have some VERY HOT presets, and thus the distortion you're getting downstream. When you use Helix as your AI and record with USB, it's a set level independent of the BIG KNOB, but if the signal is already too hot....

[DunedinDragon]

Generally speaking disabling the Helix volume knob tends to me most appropriate when going to a mixing board so that you can appropriately gain stage the incoming signal from the Helix so that it has enough headroom.  I never disable the Helix volume knob when going direct to speakers as I always set my powered speakers at unity (12 o'clock position) and control my output with the Helix volume knob.

Bear in mind that just because you have the Helix volume max'd out doesn't mean your signal won't be too hot for the preamp that you're going into whether that be the preamp on a powered speaker or a preamp on a mixing board depending on the settings you have in your signal chain.  That's ultimately why you need to manage your signal levels within each preset using the amp model's channel volume.  The signal meter on the Helix that's accessed by selecting the output block isn't perfect but it will give you a pretty good indicator of how hot your signal is.  I generally have that signal meter hitting between 60 to 65 percent and never have any problems with my patches being too hot.

[wlaycook]

11 hours ago, DunedinDragon said:

Generally speaking disabling the Helix volume knob tends to me most appropriate when going to a mixing board so that you can appropriately gain stage the incoming signal from the Helix so that it has enough headroom.  I never disable the Helix volume knob when going direct to speakers as I always set my powered speakers at unity (12 o'clock position) and control my output with the Helix volume knob.

Bear in mind that just because you have the Helix volume max'd out doesn't mean your signal won't be too hot for the preamp that you're going into whether that be the preamp on a powered speaker or a preamp on a mixing board depending on the settings you have in your signal chain.  That's ultimately why you need to manage your signal levels within each preset using the amp model's channel volume.  The signal meter on the Helix that's accessed by selecting the output block isn't perfect but it will give you a pretty good indicator of how hot your signal is.  I generally have that signal meter hitting between 60 to 65 percent and never have any problems with my patches being too hot.

 

Yep, this is exactly the conclusion I reached. My signals were too hot, largely because my channel volumes were so high.