Using Helix volume knob for amp attenuation?

[FarleyUK]

Hi all,

 

I'm using 4CM with the Helix and a JVM410HJS. I understood that to have the Helix volume at 100% was 'unity gain'; however, someone mentioned it should be at about 1 o'clock. I tried it at the gig on Saturday, and it led to me cranking the master volume on the amp the highest it's ever been in order to get the same level of volume from it.

 

Now, I'm wondering - would using the volume dial on the Helix mean that you could, potentially, use it to attenuate the valve amp and push the power tubes at lower volumes...?

[ricksteruk]

The Helix Big Volume knob is just an additional Master Volume. Yes if you set it at 1 o'clock for your "normal" level you'll need to turn your JVM master up higher than usual. (Or you could put a gain block at maybe +10dB the end of the Helix Path)

 

But no - you can't use this to drive the power tubes at a low volume like an attenuator. An attenuator's volume control comes after the power tubes - a control before is just another master volume.

[FarleyUK]

OK, thanks - make sense!

 

Good thing I've ordered an attenuator in that case ;)

[MonkeyXT]

(You wouldn't need to add a gain block; there's a level control at the end of each path which could perform this function, and it's already there waiting to go - especially handy if spare blocks are scarce etc.)

[ricksteruk]

(You wouldn't need to add a gain block; there's a level control at the end of each path which could perform this function, and it's already there waiting to go - especially handy if spare blocks are scarce etc.)

 

This is true :)

[FarleyUK]

So, just to be sure, am I right in saying that having the knob at 100% (oooh matron) IS unity gain?

 

Sounds like it to me, just want to check!