Ax8 volume output

[Brian Dixon]

It seems to me if the volume knob is set to noon that it more or less follows the volume of the built in meter. So if your patches are hitting around 0 on that meter then a volume knob at noon should be a good recording level as well as for a live board. Can anyone else verify that 50% volume is about right. Coming from an old pod x3, it was in the manual that the volume should be cranked to not introduce noise. I'm assuming this is not the same at all from what I'm finding.

 

[WERNER1]

I think you have to set each patch to the VU meters,.. but still have to verify with you "ears" on volume consistency. I typically run my Output 1 at 12:00 and that seems to work great for recording as well as sending to FOH.

 

[Philip34]

Output volume knob at noon is not 50%. It's more like 40%.

 

[Rex]

The level you get when recording depends on your gear—not just the AX8, but your interface, and how you've got your DAW set up. There's no dependable rule that says, "Set the Axe's output knob here and your recording levels are correct." It's all about the whole signal chain.

 

[vick1000]

Depends on the input sensitivety of the device receiving the signal.

 

[Dave76]

I haven't seen anything official on it but I suspect the OUT 1 knob works like typical output level adjustments i.e. it is an attenuation knob. OUT 2 specifically has a boost setting to let you tweak it to whatever you put in the FX loop so that to me implies the OUT 1 doesn't boost.

That means you'd ideally want to always set it at 100%. Anything less and you are simply decreasing your signal level relative to noise. You would want to adjust the input level of the equipment receiving the signal to the AX8 set to 100% and not vice-versa. Standard gain staging stuff and exactly why Line6 has that suggestion in their manual. I target the VU meter at around the 0 line and go a few dB above for boosts, etc. at times and the output on the AX8 never clips.

You'd only cut the OUT 1 level drastically in relatively unusual situations where you needed to quickly fix some patches that were improperly leveled or you were going into gear that couldn't be adjusted at the input (plugging headphones directly in would be an example of that).

Can someone at Fractal confirm or deny this? I think the original question rephrased is what is the ideal position of the OUT 1 knob that maximizes signal-to-noise ratio.

 

[Rex]

Where is this "boost section" on Output 2? I've never seen that.

At just about any setting of the Ouput knob, the self-noise of your guitar is going to be higher than the noise generated by the AX8, so S/N ratio is going to be pretty much a non-issue. Remember that Fractal gear can output a very hot signal. It's possible to overdrive your downstream equipment, so setting Output to maximum could be problematic. I set the Output knob on my FOH feed to noon. That gives a level that most boards can work with, and gives me room to boost and cut if needed during sound check. It's also an easy position to find in a hurry.

I set my stage monitor to 0 dB, and adjust Output 2 to whatever level I need to hear. Stage noise makes the AX8's internal noise irrelevant.

 

[Dave76]

Where is this "boost section" on Output 2? I've never seen that.

It's under I/O in the same place as input padding if I'm remembering correctly. The manual has some info on it.

At just about any setting of the Ouput knob, the self-noise of your guitar is going to be higher than the noise generated by the AX8, so S/N ratio is going to be pretty much a non-issue. Remember that Fractal gear can output a very hot signal. It's possible to overdrive your downstream equipment, so setting Output to maximum could be problematic. I set the Output knob on my FOH feed to noon. That gives a level that most boards can work with, and gives me room to boost and cut if needed during sound check. It's also an easy position to find in a hurry.

I set my stage monitor to 0 dB, and adjust Output 2 to whatever level I need to hear. Stage noise makes the AX8's internal noise irrelevant.

I'm referring to the noise floor of the line level output. This is not related to the noise of the guitar or the stage noise. As an experiment, if you set the OUT 1 level extremely low and then crank up your speaker volume to match your normal level, you'll notice lots of nastiness coming out of the speakers. At 50% OUT 1, you have much less nastiness than at low levels but much more nastiness than at high levels. Even if it seems insignificant at that level, this type of noise will sum with the noise level of all other signals coming into a mixer and the signal-to-noise ratio can be easily further degraded along the chain. More signal and less noise is pretty much always a good thing even if the noise isn't immediately perceptible.

The output from the AX8 is standard pro or consumer level line level depending on how you have it set under I/O so it shouldn't be very hot unless you happened to have it set to pro while plugging into equipment set to consumer level. That's assuming that my guess is correct that the OUT 1 level provides is attenuation only. If you need to pull back OUT 1 because of the equipment you are plugging into then you have to do that but that should be the exception, not the rule.

I personally usually go with the 3 PM position because it's relatively high, easy to find in a hurry, and I feel comforted by having a little bit of room to boost from the stage if needed.

 

[Rex]

It's under I/O in the same place as input padding if I'm remembering correctly. The manual has some info on it.

Okay, you're talking about the Boost/Pad function. Understood. That won't change your output signal level, though.

I'm referring to the noise floor of the line level output. This is not related to the noise of the guitar or the stage noise.

It's all related. in most cases, your guitar's own noise will mask any noise generated in the AX8.

As an experiment, if you set the OUT 1 level extremely low and then crank up your speaker volume to match your normal level, you'll notice lots of nastiness coming out of the speakers.

Yes, extreme settings can produce extreme results.

At 50% OUT 1, you have...much more nastiness than at high levels.

The difference between noon and max on the Output Level knob is only 6 dB. At either setting, the noise generated will be well below the 50 dB or so S/N ratio that is the best that your guitar is capable of. For all practical purposes, -50 dB + -90 dB = -50 dB.

I personally usually go with the 3 PM position because it's relatively high, easy to find in a hurry, and I feel comforted by having a little bit of room to boost from the stage if needed.

Those are exactly the reasons I choose noon on the Output knob. The difference between your setting and mine is only 3 or 4 dB, and because of the noise your guitar generates at the front of the chain, it has no practical effect on S/N. As always, go with what you're comfortable with.

 

[Dave76]

Okay, you're talking about the Boost/Pad function. Understood. That won't change your output signal level, though.

I've never used that feature but after playing around with it, it appears you are correct. I guess it is boosting before the DAC and then cutting equivalently after. I'm not sure why that would be a useful feature. I thought it let you tweak the output level so that the loop would be more flexible to whatever outboard gear you throw at it.

It's all related. in most cases, your guitar's own noise will mask any noise generated in the AX8.

I disagree with this characterization of noise. One type of noise doesn't mask another type of noise. It all sums together and builds up to the point where multiple trivial noise sources can become a problem. Keep in mind that if you are going into an FRFR or direct to PA that you are amplifying across all frequency ranges and thus dealing with noise outside traditional guitar amp speaker ranges. That's part of what I was getting at by saying it's not the same noise as guitar noise.

Yes, extreme settings can produce extreme results.

The difference between noon and max on the Output Level knob is only 6 dB. At either setting, the noise generated will be well below the 50 dB or so S/N ratio that is the best that your guitar is capable of. For all practical purposes, -50 dB + -90 dB = -50 dB.

Those are exactly the reasons I choose noon on the Output knob. The difference between your setting and mine is only 3 or 4 dB, and because of the noise your guitar generates at the front of the chain, it has no practical effect on S/N. As always, go with what you're comfortable with.

I think we pretty much agree but just have different views of what counts as an extreme low setting Mind you, I haven't actually attempted to measure any of this in any meaningful way (yet) but just think it is always a good habit to maximum signal-to-noise and the easy way of doing that is to crank the OUT 1 knob.

I think we can agree that my basic statement is correct -- the higher you set OUT 1, the higher your signal-to-noise ratio will be which is what the original poster was fundamentally asking.

 

[Rex]

I've never used that feature but after playing around with it, it appears you are correct. I guess it is boosting before the DAC and then cutting equivalently after. I'm not sure why that would be a useful feature.

Boost/Pad helps you optimize S/N.

I disagree with this characterization of noise. One type of noise doesn't mask another type of noise. It all sums together and builds up to the point where multiple trivial noise sources can become a problem.

You're right: multiple small noises can add up to significant noise. And one type of noise doesn't mask another, but one amount of noise can easily mask another. If one source of noise is 50 dB below the signal, and the second source is 90 dB below, that's a ratio of 10,000:1. It would take 10,000 of the -90 dB source to equal the noise coming from the -50 dB source. One or two or ten of those -90 dB sources won't make any meaningful difference in the noise at the output.

It's like feeding a peanut to an elephant. Technically, the elephant is heavier after he's eaten the peanut, but not in any meaningful way.

...just think it is always a good habit to maximum signal-to-noise and the easy way of doing that is to crank the OUT 1 knob.

You're right. It/s always good to maximize S/N. But sometimes, when the added noise is insignificantly small, other factors (like leaving some room to turn it up) become more important.