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ghost fizz

hoth

Inspired
What's cool is that the cliff and the axe so often make us have to rethink our basic notions of how amps work, how we hear and what we hear. So often someone says they're this HORRIBLE bug in the axe that is NEVER EVER heard in an amp. And then we find that the axe is so accurate that in desperation to find flaws in the axe we are really finding flaws in the original amps.
 

laughyouraxeoff

Experienced
What's cool is that the cliff and the axe so often make us have to rethink our basic notions of how amps work, how we hear and what we hear. So often someone says they're this HORRIBLE bug in the axe that is NEVER EVER heard in an amp. And then we find that the axe is so accurate that in desperation to find flaws in the axe we are really finding flaws in the original amps.
Totally true, and I feel that some of those flaws when set in a band type situation or recording, give the amp it's character so removing it would in some cases be a negative when having it in the mix. Now having an options to remove it I suppose could be the best of both worlds, but to be honest as picky as I am, it's never bothered me one bit.
 

Tex Axe

Experienced
I was getting this yesterday and now today just after I post a question about it ....
Its not doing it..

ghost in the machine ?
 

jlynnb1

Fractal Fanatic
this reminds me of how shocked people were to hear EVH's tracks by themselves. They couldn't believe how "fizzy" and "thin" etc, etc.....but that's exactly what gave it the mojo it had and why it sat/cut so well in a mix.
 

Singtall

Experienced
Vendor
i attribute hearing the ghost fizz to developing a better ear. i never heard it before, probably because is was mostly listening through guitar cabinets that rolled off the highs. now that i have good studio monitors and headphones at my disposal, i'm hearing all kinds of crap that i never heard before.

i actually went back to one of my 1995 recordings and listened to the intro of a song that i did with my guitar volume control rolled way back to "clean"......and sure enough, the ghost fizz is there even more than the axe-fx creates. lol.
 

FractalAudio

Administrator
Fractal Audio Systems
Moderator
i attribute hearing the ghost fizz to developing a better ear. i never heard it before, probably because is was mostly listening through guitar cabinets that rolled off the highs. now that i have good studio monitors and headphones at my disposal, i'm hearing all kinds of crap that i never heard before.

i actually went back to one of my 1995 recordings and listened to the intro of a song that i did with my guitar volume control rolled way back to "clean"......and sure enough, the ghost fizz is there even more than the axe-fx creates. lol.
Yup. I never heard it until a few years ago.

When I first was working on the Axe-Fx II I was comparing to a JCM800 and noticed that bacon-frying sound on the decay. The Axe-Fx wasn't doing it. So I spent months and months researching what caused a tube amp to do that and how to recreate it.

Incidentally, without that decay characteristic you lose the "crack" on the note attack. So the two are interrelated.

It's most noticeable when playing a simple interval. Way back I noticed that playing a major third excites it the most (i.e. F and A on the D and G strings). This causes a beat frequency that pushes you into and out of clipping. IOW, the two notes coincide at certain times pushing the amplitude to the clipping threshold. This causes a hard clip at the beat frequency.
 

Dutch

Fractal Fanatic
I was having this same thing on my main HBE preset recently. I was thinking I have to get rid of this effect somehow. I know real amps do this. Before going digital I used to have a Mesa Dual Recto, a first gen. It did this in a major way. I payed a tech hundreds of dollars to try to smooth it out of the Recto, that proves I'm not fond of that crackling bit.. It didn't quite work.

It wasn't so much the crackling itself, but that it stopped so abruptly. It doesn't fade out softly and musically, it just stops crackling, making it impossible to have chords fade out in the outtro or something...


I always put my slanted oversized 4x12 Rectocab on a stand I'd made that angled it to about 30deg pointing it upward at my ears. The top of the slant would then be at over 40deg, pointing it at my ears when standiing about 10 feet away, and over the heads of the audience, not deafening them with a beam of death. (Of course I didn't turn it up as loud, I'm not stupid. I had earplugs too). That angle may be why I actually heard the crackling from the real amp. I had another plank with the inverse angle sides so I could put the head on it without it toppling backwards. I think it looked really cool and allowed me to run the amp way less loud and still hear it over the drums. Tech loved it.


Anyway, I actually found the jumpered Plexi 100 with the master dimed does do the crackling, but it fades out more gradually than my HBE preset does, so I've been moving more to that tone...

Maybe I'll record some tomorrow.
 
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Rex

Legend!
this reminds me of how shocked people were to hear EVH's tracks by themselves. They couldn't believe how "fizzy" and "thin" etc, etc.....but that's exactly what gave it the mojo it had and why it sat/cut so well in a mix.
This, this and this!

Anyone who thinks the Axe is to fizzy should spend some time comparing famous commercial recordings with the naked guitar tracks from those recordings. It's a real eye-opener.
 

jlynnb1

Fractal Fanatic
i attribute hearing the ghost fizz to developing a better ear. i never heard it before, probably because is was mostly listening through guitar cabinets that rolled off the highs. now that i have good studio monitors and headphones at my disposal, i'm hearing all kinds of crap that i never heard before.

i actually went back to one of my 1995 recordings and listened to the intro of a song that i did with my guitar volume control rolled way back to "clean"......and sure enough, the ghost fizz is there even more than the axe-fx creates. lol.
exactly, and this goes back to what Cliff said about having your ear up to the cabinet. We are hearing from that vantage point...which makes our tones more consistent from stage to foh but takes a while to adjust to after having cabs blasting us from behind all of our guitar playing lives. We never heard all the things that were there because we were never at the vantage point to be able to hear them.

it's the same as when a guy thinks his tone is amazeballs then he gets in the same location as the audience, in the beam of death, and he doesn't understand why it sounds crappy. It ALWAYS did, lol....he was the only one who didn't know it!
 

javajunkie

Moderator
Moderator
This, this and this!

Anyone who thinks the Axe is to fizzy should spend some time comparing famous commercial recordings with the naked guitar tracks from those recordings. It's a real eye-opener.
I've been doing that as of late. Not only that but hum, buzz, and noise bleed. A lot of the tones, that if were pasted here out of context, would get blasted for being so-so or downright bad. Put them in a mix though and they really just work.
 

Dutch

Fractal Fanatic
I've been doing that as of late. Not only that but hum, buzz, and noise bleed. A lot of the tones, that if were pasted here out of context, would get blasted for being so-so or downright bad. Put them in a mix though and they really just work.
Where do you get those?
 

Phostenix

Power User
The question I have is whether these solo guitar tracks are unprocessed recordings of the mic'd amp or if they are the processed solo'd channel of the actual mix. The raw amp recordings very likely didn't get printed to tape in the final mix, so it's only an exercise in hearing what the audio engineer had to start with. If these stem tracks were extracted from the mix using filtering software, then they also aren't a valid representation of what the real solo'd track sounded like.

I now also listen more carefully to recordings for sizzle and brightness of the guitar tracks. Even when cranked to very high levels, I don't hear the kind of high frequency content in recordings that I can get out of the Axe (straight out of the cab). Sizzle definitely brings electric guitars out of a mix, but I'm not convinced that we always want ALL of the sizzle ALL of the time. What I am becoming more convinced of is that AEs remove a lot of it as part of the recording & mixing process. I also think we can separate complex mixes & simple mixes (e.g., a single guitar, bass, and drums) in the sizzle decision. In a simple mix, you don't need much sizzle to "cut through" the mix since there isn't anything in the midrange competing with you.

I think this is another "horses for courses" (as Scott Peterson would say) discussion. Sometimes you want the sizzle to cut through the mix, and sometimes you want to be big & fat & smooth to fill the mix.

Sent from my Nexus 7 using Tapatalk 4
 

barhrecords

Axe-Master
I've been doing that as of late. Not only that but hum, buzz, and noise bleed. A lot of the tones, that if were pasted here out of context, would get blasted for being so-so or downright bad. Put them in a mix though and they really just work.
A lot of recording engineers and mixers work with the whole song up vs. agonizing over each microphone in solo.

The result can really be some weird sounding stems in solo for sure.

With the advent of re-amping, the specialist guitar / bass guys can agonize in post to get the perfect tracks.
 

Rex

Legend!
The question I have is whether these solo guitar tracks are unprocessed recordings of the mic'd amp or if they are the processed solo'd channel of the actual mix. The raw amp recordings very likely didn't get printed to tape in the final mix, so it's only an exercise in hearing what the audio engineer had to start with.
That's the whole point. These guitar tracks do indeed represent what the audio engineer had to start with—the sound coming from the amp. It doesn't matter whether they've been processed or not. The fizz you hear comes from the amp, not from a signal processor.


If these stem tracks were extracted from the mix using filtering software...
Stems are the sources used during mixdown.


Sometimes you want the sizzle to cut through the mix, and sometimes you want to be big & fat & smooth to fill the mix.
That's why the new firmware lets you chose from combinations of authentic, smooth and ideal modeling.
 

smcrosby

Power User
The "fizziness" of clipping is determined by how "hard" the clipping is. There are three primary places that clipping occurs in a tube amp: the preamp tubes, the phase inverter and the power tube plates.

Preamp tube clipping can range from soft to hard depending upon the design. Phase inverter (PI) clipping, which is actually the power tubes grids clipping, is very hard. Power tube clipping ranges from soft to hard depending upon the amount of negative feedback in the power amp.

Preamp tube clipping is comprised of cutoff, which is soft, plus saturation, which tends to be hard. Actual saturation rarely occurs because most preamp stages are designed such that the grid clips before the tube enters saturation. Grid clipping is hard. Local negative feedback is used in the form of cathode caps to shape the response of a preamp stage. If there is no cathode cap then there is negative feedback at all frequencies which increases the hardness of the clipping. The last stage usually dominates the clipping. Some amps have no cathode cap on this stage, e.g. JCM800, and therefore have hard preamp clipping. The Axe-Fx II does not expose the negative feedback settings for the preamp stages to the user, these are hard-coded. Reducing the Triode Hardness parameter will soften the clipping more-or-less depending upon the particular amp model.

In a typical tube amp the power tubes start to clip right about the same time the PI/grid clipping occurs. This is intentional so as to get the most power from the tubes. However some amps are intentionally mismatched as the designer's intent was to get more power tube clipping than PI clipping (i.e. Trainwrecks). The Transformer Match parameter adjusts the relative onset of power tube vs. PI/grid clipping. Lower values will cause the PI/grid clipping to occur before power tube clipping. Higher values will cause the power tubes to clip before the PI. Note that the power tube plates follow the impedance curve of the speaker so while the PI/grid may be designed to start clipping first, this only occurs in the midrange. At frequencies above 1 kHz or so the power tubes clip first since the voltage on the plates increases as a function of the speaker impedance. The first thing to clip tends to dominate as once you enter clipping the effect of clipping elsewhere is diminished.

Negative feedback around the power amp attempts to linearize the transfer function. The more negative feedback the more the power amp is linearized. However this also causes the clipping to become harder. A power amp with no negative feedback will go into clipping softly. As you increase the negative feedback the "knee" gets sharper. The Damping parameter is the negative feedback control. Higher values give more feedback and harder clipping.

Presence and Depth work by modifying the negative feedback. As you increase them the feedback gets less so by turning up the Presence you get softer clipping in the power amp.

Therefore to decrease the hardness of the power amp clipping: reduce Damping, increase Presence, increase Transformer Match.
To reduce preamp clipping hardness reduce Triode Hardness.
There is no parameter exposed to adjust the PI hardness.

HOWEVER, the relative hardness of clipping is not all that audible. You have to listen closely. The IR is far more important in the final result. Some IRs let through a lot more high frequencies and therefore sound more fizzy.

Furthermore overanalyzing this is inadvisable. Many amps are specifically designed to clip hard as this gives a more aggressive tone that fits better in the mix. Some amps actually attempt to increase the hardness of the clipping as much as possible by using diode clipping or using very high values of negative feedback (i.e. Modded Marshalls, Camerons, 5150 III). Listening at low levels fools your ear. Our ears are more sensitive to midrange at low listening levels. This means we hear the clipping differently than when listening at the actual level the real amp would be generating.
Cliff - thank you for this. This knowledge sharing by FAS and its many Staff and user gurus is a good part of why I became a Fractalite in the first place ... oh yeah ... that and that AXE FX II thingy that you guys sell and constantly enhance with FW updates!!! :)

Seriously, the key to FAS user's unlocking the magic and getting the most out of their little black box is having this kind of access to the knowledge and perspective shared on this Forum by so many. :encouragement:
 
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