Technical Question

FractalAudio said:
I do hear a very slight difference. I suspect it's the slightly different loading presented to the instrument as if you measure the inputs with an audio analyzer there is no difference. Audio analyzers have low output impedance.

If it bothers you, use the rear input.

No piece of gear will ever be perfect. Obsessing over minutiae won't remove imperfections.
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I have to agree. I would like to mention one thing I can notice and have even documented (visual inspection of the waveform reveals a difference) with a buffered guitar having an output impedance of about 100 ohms (very low).

If I set the front input according to instructions so that the red LEDs are "tickled" I hear a slight softening of the pick attack, and this has nothing to do with the high output impedance of a passive guitar. However, I want to stress that the difference is VERY subtle and I have to loop side by side recordings and toggle between some VERY sharp pick attacks to notice.

If I set my level and "pretend" the red LEDs represent the clip point and not 6dB below it, the difference goes away and the sound is the same. If you set your levels such that the red LEDs NEVER light up (and there's no reason not to do this - the noise floor is so low to begin with WHY would anyone want to come within 6dB of clipping the input? That's insane in a 24 bit world IMHO) you should not hear any difference with an active instrument. I can't comment of a passive one.

It's natural when you (or at least I) first buy a box to "test" everything out. But let's get practical. If you have to pick as hard as you can without breaking a string, push it within 6dB of the input clipping, loop the signal and listen to it 100 times to tell any difference...it's time to quit testing and make some music. That's just my practical take on it.
 
rm60 said:
.... .... .... hmmm, maybe pick dynamics control in Fware++ ? .... ..... ...
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I thought that was kind of the point of the current "dynamics" section that was added, but perhaps not. The Kemper apparently has some kind of pick attack adjustment but I haven't bothered to read about it.

I'd like to reiterate that if you simply don't light up the red LEDs on the input meter this becomes a non-issue. I tested the crap out of the front vs. rear and the front driven to the point of the red LEDs lighting up vs. not lighting up.

Use the front input, but DO NOT "tickle" the RED LEDs and you will experience no issues with the input itself. This is not just test equipment speaking, it is the most impulse like, sharpest, widest bandwidth pick attack you could ever hope to create, something as close to a pure impulse as I could create, and if the RED LEDs don't light there is no degradation both looking at the resultant waveforms visually and to my ears (which are damn good BTW IMO - I hear stuff other people couldn't hear in a million years, especially distortion and smearing of transients).

I DO think the manual should say "don't let the red LEDs light up", even though they do not indicate clipping. What is really a mystery to me is why there IS no actual input clipping indicator, but if you ASSUME the RED LEDs are the clip point and avoid "tickling" them you're good to go and will NOT get any distortion from the "soft clip" limiter.
 
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thewizardguy said:
I didn't think I'd hear it, but I do hear more through the rear. Weird.
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Two questions.

1) Did you allow the red LEDs to light up even for an instant when using either input?

2) Do you have an active guitar (one that needs a battery and has some type of electronic circuit to amplify, buffer, or equalize the pickups)?
 
Search4Tone said:
I'd like to reiterate that if you simply don't light up the red LEDs on the input meter this becomes a non-issue. I tested the crap out of the front vs. rear and the front driven to the point of the red LEDs lighting up vs. not lighting up.
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In your testing, what value did you use for Input Impedance?
And were you using active or passive pickups?
 
I used whatever the default value is - I'd have to check. However, it shouldn't matter. As I mentioned, my active guitar has an output impedance of about 100 ohms, so regardless of the input impedance the resistance and capacitance of the input would not affect a 100 ohm source impedance.
 
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