Input 1/Instrument A/D sensitivity

TakaraGold

TakaraGold

Experienced
Hi guys,

Just wondering how this should be set, I'm getting input clipping even at very low values like 18%, if set at zero I get no clipping, and sounds come out alright as well.
Using always midgain passive pups, single coils, got a heavy right hand, so clipping comes up every now and then. Setting it this low will affect how lower output pickups sound?
 
Mine is also set at 5% with PRS Tremonti and Modern Eagle V pickups in my three guitars.

I believe that below 5% can cause some tonal changes (gain reduction?)
 
Out of curiosity why not just set it to 0% all the time to prevent ever having clipping and keep a consistent S2N when switching instruments? Does anyone ever move it once it's set? If it has no effect on tone and auto adjusts on the digital side I don't quite see why a value other than 0 would be necessary if the gain staging is automatically compensated.
 
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What I've understood from other discussions here, is that signal to noise ratio suffers from too low sensitivity values.
 
What i find weird is that all of my guitars tickle the red at different levels, but the last gig i played, i started with one that had more low mids, and when i switched to another, which was brighter, the sound man had to bump me up considerably because my send to FOH dropped.

Ive tested almost all my guitars in reaper, looking at direct wave forms. I know which ones are hotter but even with eq differences, some still get lost in the mix.

Ive tried bumping the input gains on them. Still doesn't affect the processed signal much.
 
ToneRanger said:
What i find weird is that all of my guitars tickle the red at different levels, but the last gig i played, i started with one that had more low mids, and when i switched to another, which was brighter, the sound man had to bump me up considerably because my send to FOH dropped.

Ive tested almost all my guitars in reaper, looking at direct wave forms. I know which ones are hotter but even with eq differences, some still get lost in the mix.

Ive tried bumping the input gains on them. Still doesn't affect the processed signal much.
Click to expand...
Sounds to me like differences in how amp model compression reacts to different guitars more than anything to do with input sensitivity.
 
ZackSeifMusic said:
Out of curiosity why not just set it to 0% all the time to prevent ever having clipping and keep a consistent S2N when switching instruments? Does anyone ever move it once it's set? If it has no effect on tone and auto adjusts on the digital side I don't quite see why a value other than 0 would be necessary if the gain staging is automatically compensated.
Click to expand...
The SNR is dictated by the converters, not the source. You want as hot a signal as possible into the converters for best SNR.
 
Since there are a couple threads related to this:
1. The noise floor of an A/D is fixed. For example the Cirrus Logic converters we use have a dynamic range of 114dB. That means the noise is down 114dB relative to full-scale.
2. You only get 114dB of dynamic range if the input to the converter is at the voltage which generates a full-scale output.
3. For every dB that the input is below that voltage the dynamic range decreases by the same amount.
4. If your input to the A/D is 20dB below full-scale then your dynamic range drops to 94dB for the aforementioned converters.
5. Therefore you want to drive the A/D with as hot a signal as possible (without clipping) to get the best dynamic range (least noise).

The same holds true for a D/A converter. To get the lowest noise from a D/A converter you want to run it as "hot" as possible. Now, the difficulty here is that running the D/A hot can generate a large output signal. So what we do is give you the Boost/Pad control (on outputs 3 and 4). The Boost/Pad control boosts the digital signal by XdB and reduces the analog gain after by the same amount. This allows flexibility in the outputs. If you need a hot signal for driving a power amp you set the Boost/Pad to 0dB. If you need a lower signal for interfacing with effect pedals you can reduce the output level.

For example, if you are interfacing to stomp boxes the typical maximum signal that a stomp box can handle is about 3V. However, the outputs of the Axe-Fx III can drive about 12V. If you set the Boost/Pad to 12dB the maximum output is now 3V and your noise is reduced by 12dB.
 
Having grown up with tube amps, I find it surprising that anyone could be bothered by the noise levels in the Axe-FX. All of my favorite recordings are flooded with amp noise and tape hiss. It doesn't bother me at all. What does bother me is clipping. So I just set the level low enough for the hottest pickup and the heaviest hand, and adjust the Noise Gate to a sensible setting. Not a problem.
 
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