The Overlooked Input Knob

B

bjjp2

Power User
Where you set the "Input" knob makes a huge difference in the sound of a patch, comparable to adjusting a guitar volume.

When downloading a patch, where should I assume the input knob is set? I've read the general consensus that it's when the red light flashes occasionally, but I find that very hot.
 
The general consensus is:

- Grab your hottest guitar
- Select your hottest pickup configuration
- Dime the guitar volume knob
- Play as hard as you can
- Set the Axe-FX input knob so that it only occasionally lights, when playing your hardest (most of us refer to that as "tickling the red").
- Leave it there and never touch it again (so to speak)

With this set up, you're getting the most out of the Axe. Any guitar (or pickup combination) that has lower output will perform as it should, i.e. not as hot as your hottest one. Which is exactly the same as what a "real" amp would do.

And if you find that's too hot, you have a million different ways to adjust your gain staging inside your patches.
 
I tend to keep that knob pinned all the way up, or backed off just a touch on humbuckers.

I wonder if the knob aught to have more range? I got a doz or so guitars and find that even the hottest ones won't slam the input solid red with the knob all the way up. With my weakest output Strat I can barely see a blink of red at all. I tend to gravitate towards lower output, Alnico magnet vintage pickups though.. maybe I simply don't have any 'hot' guitars?
 
I have an ESP with an EMG 60 in the bridge. My input knob is at about 1 o'clock and I tickle the red when I'm really digging in. If I crank the input knob, I'm gonna be slamming the red.

That being said, my strat tickles the yellow with the same setting.

Dpoirier is right, though. I believe that's in the manual. This gives you the best signal:noise ratio.
 
Dpoirier said:
The general consensus is:

- Grab your hottest guitar
- Select your hottest pickup configuration
- Dime the guitar volume knob
- Play as hard as you can
- Set the Axe-FX input knob so that it only occasionally lights, when playing your hardest (most of us refer to that as "tickling the red").
- Leave it there and never touch it again (so to speak)

With this set up, you're getting the most out of the Axe. Any guitar (or pickup combination) that has lower output will perform as it should, i.e. not as hot as your hottest one. Which is exactly the same as what a "real" amp would do.

And if you find that's too hot, you have a million different ways to adjust your gain staging inside your patches.
Click to expand...

I've been adjusting the input everytime I swap between my strat and lp thinking that I'm not getting the best out of the strat with the lower input setting. This is great news for me - thanks!
 
Nic said:
Dpoirier said:
The general consensus is:

- Grab your hottest guitar
- Select your hottest pickup configuration
- Dime the guitar volume knob
- Play as hard as you can
- Set the Axe-FX input knob so that it only occasionally lights, when playing your hardest (most of us refer to that as "tickling the red").
- Leave it there and never touch it again (so to speak)

With this set up, you're getting the most out of the Axe. Any guitar (or pickup combination) that has lower output will perform as it should, i.e. not as hot as your hottest one. Which is exactly the same as what a "real" amp would do.

And if you find that's too hot, you have a million different ways to adjust your gain staging inside your patches.
Click to expand...

I've been adjusting the input everytime I swap between my strat and lp thinking that I'm not getting the best out of the strat with the lower input setting. This is great news for me - thanks!
Click to expand...

I've been doing the same when I switch between guitars. Makes sense to set it and forget it!
 
Musicman, slightly off topic but how do you switch guitars out of interest? I've been engaging the tuner to silence the noise, unplugging, then plugging in but I'd like something a bit quicker and smoother that does not degrade my sound.
 
Robboman said:
With my weakest output Strat I can barely see a blink of red at all. I tend to gravitate towards lower output, Alnico magnet vintage pickups though.. maybe I simply don't have any 'hot' guitars?
Click to expand...
All my Strats have low output pickups and none of them touches red. I set it with my old Anderson designed Schecter which is my 'hottest' in the house to trigger red and the Strats all sound like they are supposed to.
 
I think having the input level at NOON is the best. Why? I used to have the input level at 1 o'clock and when I A/B'd my Recto settings with a real Dual Rectifier and although the tones were really close I noticed that the Axe-Fx had less low end. Now... I lowered the input down to noon and somehow it sounded THE WAY IT'S SUPPOSED TO SOUND. Low end was there and even the sizzle started to sound the same. The tone got a lot flatter which is a really good thing! The whole point in having different guitars/pickups has a lot to do with pickup volumes and you can't change the input level in a real amp either. A single coil will be much quieter than a humbucker but if you turn up the single coil signal you're doing something that I think FAILS. Do you think that real amps take in guitar signal that "peaks red"? I don't think so. RED LED = FAIL!!!!!!! If you wan't to use boosts then add a boost before the amp. Having the input level too high will add the boost to all your presets.

I say lower the volume knob to make the Axe-Fx sound less digital and make your tone cut. Just try it out: LESS IS MORE!
 
There is no analogy between the input level control and anything on a physical amp. Hopefully we all can agree that the designer of the Axe-Fx knew what he was doing in providing this control, along with signal level LEDs and explicit instructions in the manual to aid users in setting it properly. I can confirm its purpose and utility from an understanding of the relevant circuitry, none of which exists in a tube amplifier.

Setting the control at "noon" is not the same as unity gain. There is nothing magic about the center of the travel of the input level control. Instructions for its proper setting are provided in the manual. You're of course allowed to set it however you like on your Axe-Fx, but that has no effect on its purpose or proper use.

Once you've tweaked a preset with a particular setting of the input level contol, changing the control will affect your tone, just as changing the signal level at any point prior to the amp and/or drive sim (e.g., guitar volume, level parameter in any internal blocks) will change it. If turning down the input level makes your tone sound better, you can get the exact same result in a number of other ways (e.g., reducing the Drive parameter in the amp block) that will not compromise the signal/noise performance of the system.
 
Jay Mitchell said:
If turning down the input level makes your tone sound better, you can get the exact same result in a number of other ways (e.g., reducing the Drive parameter in the amp block) that will not compromise the signal/noise performance of the system.
Click to expand...

Is this true? Is there really no difference between turning up either the hardware Input level or the Amp block Drive control? The block diagram in the manual implies this by placing the Drive control before the Preamp block, but the description includes text that suggests that, at least for some amp types, there is some tone shaping involved:

Axe-Fx Manual said:
On some amplifier types the drive control has a treble peaker (like the original). When the drive is turned down the low frequencies are attenuated more than the high. As the drive is turned up the low frequencies are increased more.
Click to expand...
 
tnolanjr said:
Is this true? Is there really no difference between turning up either the hardware Input level or the Amp block Drive control?
Click to expand...
If you have the bright parameter engaged, changing drive will have a different effect than changing the level upstream of the amp block. In that case, you can place a null filter in front of the amp block and adjust the signal level with that. My point was that there are many ways other than changing the input level control to alter the level of the virtual "signal" that hits the amp block.

The input level control has a specific purpose. I think it's a safe bet that the intended purpose will be best served when it is set according to the instructions in the manual. Beyond some reduction in signal/noise (or driving the input circuitry into compression if you set it too hot), there's no harm done if you choose to set it some other way, but there's no magic benefit to your tone from doing so either.
 
Once again Jay I'm pretty sure you are wrong. Yes, having the input level higher will give you more gain and you can compensate this with the gain knob of the amp simulator. There's a difference though. Having the input level higher is like having a clean boost. It's a good tone... don't get me wrong but it definately eliminates most dynamics in your playing. This means it's easier to play with the input knob higher but at least I think that it also eliminates some of the tube amp dynamics and makes you sound more digital. Just like the DRIVE block doesn't work in a similar way as with real amps because it's not driving tubes with higher volume since there are no tubes in the Axe-Fx. Mostly it just adds gain and it made my every patch sound like Boss GT. My advice: If you have the input level all the way up then you are probably doing it wrong!

It's a taste issue... now Jay please do your thing! :lol:
 
I agree with Jay (and the manual). The input knob is there to maximize the signal-to-noise ratio. If the user feels, after setting the input knob according to the manual, that the signal is hitting the amp block too hard, one should use eq/filter/mixer/etc or amp's drive to reduce the level before the preamp (this would also reduce noise level). But that is just the recommendation, of course the user can do what ever (s)he likes.

CK, have you tried A/B'ing with the higher input knob setting (setup according to the manual) and then reducing the level before the amp block? It would be interesting to know whether the results (ignoring signal-to-noise) are the same as just turning down the input knob.
 
knoll said:
I agree with Jay (and the manual). The input knob is there to maximize the signal-to-noise ratio. If the user feels, after setting the input knob according to the manual, that the signal is hitting the amp block too hard, one should use eq/filter/mixer/etc or amp's drive to reduce the level before the preamp (this would also reduce noise level). But that is just the recommendation, of course the user can do what ever (s)he likes.

CK, have you tried A/B'ing with the higher input knob setting (setup according to the manual) and then reducing the level before the amp block? It would be interesting to know whether the results (ignoring signal-to-noise) are the same as just turning down the input knob.
Click to expand...

Haven't tried that. I don't actually see a point to even try that since it'll just complicate simple things. Having the input at noon seems to work for me just like I want it to. I suggest everyone to use whatever works best for them. My own principle: Simple patch -> less coloring -> realistic tone. I just have one amp block and 1/2 cabs in just about every patch I've made. (Ofcourse WAH and DELAY in the lead patches and I got different clean effects too.)

I'm just giving information which I consider to be advice. Try it out but if it doesn't work then don't use it. Remember to add drive after lowering the input level.
 
My 0,02...
S/N Ratio is where it counts with this kind of equipment. And I'm inclined to follow the guidelines of the designer in this matter. He's rarely mistaken.
A blinking red LED doesn't mean "fail" BTW. It's not an overload warning, it justs indicates that the headroom's getting tighter. The Axe-Fx input isn't the same input as on a tube amp, it's regulated and optimized for good reason and the knob to accomplish it is there for a purpose. My guess is that keeping the input level below the optimal position LIMITS the available headroom and dynamics instead of improving them.
IMHO "keep it at noon" is a highly subjective advice and disregards the differences between pickups etc.
Ey Clark, didn't you previously advice that all high freqs should be boosted about 5dB to make the Axe "sound like it should"? ;-) Still doing that?
 
I think the point is that the creator (Cliff), the Axe-fx manual, and many other people on this forum have been busting their balls trying to get the users to understand the simple instructions to use the input level the way it was intended: to maximize signal-to-noise ratio.

When someone posts recommendations or advice that point potential readers in a different direction, this someone is bound to receive some pushback on their advice. That's all. Feel free to set it at noon if that suits you. But if you advise others to set it at noon, many of us will provide counter-advice, in accordance with Cliff's own design.
 
Clark Kent said:
I'm just giving information which I consider to be advice.
Click to expand...
You're doing so in an accusatory way, however ("FAIL"), and the accusation is leveled at Cliff. I'll repeat my statement that I personally happen to believe that Cliff knew what he was doing when he designed the input/conversion circuitry (including the level control and level LEDs), as well as when he wrote the instructions for its proper use. Apparently you disagree with my position, but that could lead one to wonder why you decided to purchase and keep the device.

Try it out but if it doesn't work then don't use it. Remember to add drive after lowering the input level.
Click to expand...
See above. If you have the bright switch engaged, increasing drive will alter your tone. In fact, it will become "darker" and/or "fatter." If your advice works, the other techniques recommended here will produce the same tonal result but leave your signal/noise at the optimum level.

Edit: Per Cliff, the level at which the red LED illuminates is 6dB below the threshold of the input compressor (the input will not go into hard clip). I.e., if you RTFM and follow the instructions, you'll have ~6dB of headroom - that's a lot - when you play the guitar as loud as you can.
 
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