Basic question on output levels

greiswig

Power User
I've always been pretty conservative on my output levels, I thought. Then in this thread, Cliff said that my levels were "way too hot" and that was why I was getting buzz.

I'd gone back at the time and checked, and the scenes in question on that preset were running around -12dB according to my UA Apollo Twin.

So I don't understand what was too hot, but I lowered my presets 6dB further anyway. But now I'm thinking: how can that be right? What I want to do is get all my scenes and presets to about the same overall level (via audio and meters), and have a filter block that lets me boost volume for leads, typically by 4-6dB. So I know that I have to leave probaby 2dB over even that for headroom and transients. But that means that my non-boosted patches could be averaging about -8dB without issue, right? Not -18dB where they are hitting now as measured via AES input on the Apollo Twin.

According to the meters, the analog outputs only get as loud as the AES output when the output control is dimed, so that shouldn't be an issue either.

Am I missing something?
 
Use the VU meters in the Layout view, zoomed out. The user manual describes this.

You don’t want to clip things before it even leaves the Axe.
 
I've always been pretty conservative on my output levels, I thought. Then in this thread, Cliff said that my levels were "way too hot" and that was why I was getting buzz.

I'd gone back at the time and checked, and the scenes in question on that preset were running around -12dB according to my UA Apollo Twin.

So I don't understand what was too hot, but I lowered my presets 6dB further anyway. But now I'm thinking: how can that be right? What I want to do is get all my scenes and presets to about the same overall level (via audio and meters), and have a filter block that lets me boost volume for leads, typically by 4-6dB. So I know that I have to leave probaby 2dB over even that for headroom and transients. But that means that my non-boosted patches could be averaging about -8dB without issue, right? Not -18dB where they are hitting now as measured via AES input on the Apollo Twin.

According to the meters, the analog outputs only get as loud as the AES output when the output control is dimed, so that shouldn't be an issue either.

Am I missing something?
Maybe he meant within the unit. For example, the amp block can be clippin within the unite while you may still have plenty of headroom in your interface
 
I have used the VU meters in the past. Honestly, those are the only really useful meters in the on-screen UI from what I can see. Apparently I've been fooling myself, because none of the other meters show that level of detail:
  • the meters on the Home screen (with Home/Presets/Meters tabs) are one solid color, and I guess I assumed they were not showing clipping because they didn't show red. But they aren't reflecting the same thing as those VU meters. I don't know if that's by design or not.
  • The meters on the blocks are the same way. None of them show red, and I gather that's because you really can't clip an internal block? Even the output blocks don't seem to reflect the same thing as those VU meters.
  • If the VU meters are really THE critical piece, it would be great to have those be ubiquitously displayed somehow. On the home screen, or at least the meters tab there. OR have the output meters show the same thing as those VU meters. I'm not understanding what is being measured by the VU meters that isn't being measured on the other meters.
 
I've always been slightly confused about how to create a unity gain setup using the level control on individual blocks and the output level control knob on the front of the unit. Specifically, I have never understood why the quoted section of the user manual is written this way...
  • Output Level Knobs 1–4 — These knobs independently control the volumes at the corresponding rear panel outputs. The Output 1 knob simultaneously controls Output 1 XLR and quarter-inch jacks, and the headphone output level. Outputs 3 and 4 are at unity gain when set fully clockwise.
What about the setting for output level 1 and 2, where should they be for unity gain? Is it at unity gain at noon (like @austinbuddy used to say) or should it also be fully clockwise for unity gain like 3 & 4, like austinbuddy now says is correct. Can this be clarified in plain english for those of us struggling to understand unity gain from input to output? Thanks for any insight the forum can provide.
 
Can this be clarified in plain english for those of us struggling to understand unity gain from input to output?
Why do you want unity gain for a low-output electric guitar?

Unity gain is not the goal. The resulting effected signal for a full tone (not 4CM) probably should be louder than the guitar’s low signal alone.
 
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  • If the VU meters are really THE critical piece, it would be great to have those be ubiquitously displayed somehow. On the home screen, or at least the meters tab there. OR have the output meters show the same thing as those VU meters. I'm not understanding what is being measured by the VU meters that isn't being measured on the other meters.
Here's my understanding of the meter situation:

The layout vu meters show the level at the output block. Those meters show the same information as the digital (usb) output meters on the meters screen, but in a more detailed and convenient display that also presents a block level control. On the other hand, the meters screen shows meters for other points in the chain, so those two screens serve different purposes.

The front panel level led's (and the meters screen analog meters) are slightly different than the vu meters since they reflect the trim of the front panel output level knobs. Note that if you have the front panel output level knob turned all the way up, then the front panel meters reflect the digital output, so do that if you want output meters for your digital output that you can see at all times.
 
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Why do you want unity gain for a low-output electric guitar?

Unity gain is not the goal. The resulting effected signal for a full tone (not 4CM) probably should be louder than the guitar’s low signal alone.

Chris, thank you for the reply. If unity gain is not the goal, then why is it mentioned in the manual for outputs 3 and 4? If using the AXE as an audio interface, or if using it to bring in audio via USB, knowing how to achieve unity gain is a relevant goal in my opinion. If I'm looking at this wrong, please let me know the proper perspective. Thanks again.
 
Chris, thank you for the reply. If unity gain is not the goal, then why is it mentioned in the manual for outputs 3 and 4? If using the AXE as an audio interface, or if using it to bring in audio via USB, knowing how to achieve unity gain is a relevant goal in my opinion. If I'm looking at this wrong, please let me know the proper perspective. Thanks again.
Out 3 and 4 are designed for the 4CM and in that situation, you want unity gain as you’re interfacing with a real amp which usually expects guitar-level signals.

For a fully modeled signal that’s line level out, you don’t need unity gain, as you interface with gear that accepts line level signals.

Unity Gain is not some magic setting. It’s needed in specific situations.
 
Here's my understanding of the meter situation:

The layout vu meters show the level at the output block. Those meters show the same information as the digital (usb) output meters on the meters screen, but in a more detailed and convenient display that also presents a block level control. On the other hand, the meters screen shows meters for other points in the chain, so those two screens serve different purposes.

The front panel level led's (and the meters screen analog meters) are slightly different than the vu meters since they reflect the trim of the front panel output level knobs. Note that if you have the front panel output level knob turned all the way up, then the front panel meters reflect the digital output, so do that if you want output meters for your digital output that you can see at all times.

I appreciate you weighing in, GlennO.
I'm not talking about the LED meters in front at all. If you're right, and the VU meters reflect the same thing as the USB output meters do (when Output 1 and Output 2 are maxed), then I'd expect a similar display on each. But that's not what you get: it looks like the USB output meters are showing the same as the VU meters up to the point where the VU meter starts to go into the red. I'm guessing that because those green meters are full at about the same time the blue section of the VU meter is full. But that's just a guess, and I don't know why they are different graphically.

And the output blocks themselves, in the layout, don't peg their meters at the same time either of those other two meters is (apparently) showing 0dB.
 
I appreciate you weighing in, GlennO.
I'm not talking about the LED meters in front at all.
Sorry. You asked how to get a ubiquitous meter of the digital output, so I was explaining how to do that.

If you're right, and the VU meters reflect the same thing as the USB output meters do (when Output 1 and Output 2 are maxed), then I'd expect a similar display on each. But that's not what you get: it looks like the USB output meters are showing the same as the VU meters up to the point where the VU meter starts to go into the red. I'm guessing that because those green meters are full at about the same time the blue section of the VU meter is full. But that's just a guess, and I don't know why they are different graphically.

And the output blocks themselves, in the layout, don't peg their meters at the same time either of those other two meters is (apparently) showing 0dB.

I don't quite follow what you're saying. All the meters seem to agree for me. In other words, there may be some slight scaling differences where the vu meters have more resolution near the top of the range to assist with level adjustment, but the important thing is they all hit the maximum value at the same time. That's not surprising since the top of the range is easily defined for digital output.
 
I put a signal generator into the unit so I could get consistent photos of the meters to show you what I mean.

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This is the kind of thing I'm talking about. Red usually means "bad" or clipping. It does on the LED meters, which aren't into the red here. But on the VU meters, the manual didn't seem too clear: it wants you "hovering around the red line." The VU meters are clearly red here. But the LED meters, when they go red, the outputs are clearly clipping.


eVQv6zVKT12SrSDzQehB1w.jpg
And these meters, at the same levels, have only a vague space at the top, not like the red line on the VU meters. If the VU meters are what we should be using, these meters would be more helpful if they also had a red (or better yet yellow, if it isn't really clipping until the top of the meter is hit) area to tell us when we're hitting the target area.
 
I see what you're saying. Yes, the color schemes are different on the various meters. I can see how Cliff might defend the current way it works by arguing the layout page (and output block) is for adjusting the preset level, so the important information there is not when it is clipping, but when it is over the "ideal" level and that's what red is used for on that page. Whereas the led lights on the front panel are there to alert you to clipping, so it makes sense to have red serve a different purpose there. I think agree with you though, that red should be reserved for clipping.
 
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