Axe-Fx III Firmware 23.03 Beta #1

James Freeman said:
Still wondering why some model defaults have that and others don't.
Reason being, if the amp was modeled accurately there is no need for external quick fixes.
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people do this with the real amps with either eq pedals or the typical tube screamer trick. so the amp was modeled accurately.
 
James Freeman said:
Still wondering why some model defaults have that and others don't.
Reason being, if the amp was modeled accurately there is no need for external quick fixes.
Click to expand...
I figured input low cut defaults to a higher frequency when the amp has that behavior built in. Guess I don't know for certain if that's right, but if the model is like that and sounds like the amp, that's indirect confirmation.
 
James Freeman said:
Are you're saying that setting the input eq tab completely flat yields the most accurate response from the amp?
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My bet is that the most accurate response is having it set the way it is when you reset the amp block using that amp.
As I said above, some real amps are built like that.
I think.
 
James Freeman said:
Are you're saying that setting the input eq tab completely flat yields the most accurate response from the amp?
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Resetting the channel and setting Speaker Thump manually (where it makes sense) yield the most accurate response, from my understanding. Some models have different built-in low cuts on the Input EQ.
 
GuitarGuy316 said:
6L6 550W
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Oh man, where can I buy a 550 W version?
Futurama Buy GIF
 
Saarang Narayan said:
That 2203 is so inspiring! I've been playing on it for about an hour now and I was just supposed to be updating and checking if my usual presets sounded okay...
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What difference do you get from the 2203 vs the 50w 2204, just curious. Also, I know you as the "Friedman fellow" lol any itches the new 2203 scratches that are similar? Maybe after flicking the sat switch or using a TS9? I'm curious, haven't been able to update this morning cause my wife is sleeping near my gear lol
 
James Freeman said:
That's wham I'm asking, why is it not internal?
To me it looks like a last moment fix.
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When you say internal, do you mean not editable by the user? I'm not following how it seems last minute. Don't real amps have low cut filters built in, and isn't this one in the same place as a real world amp?

I think this is authentic, and the only difference is that this is instantly tweakable. Let me know if I'm misunderstanding what you're saying.
 
James Freeman said:
Still wondering why some model defaults have that and others don't.
Reason being, if the amp was modeled accurately there is no need for external quick fixes.
Click to expand...
The models default to the values of the input filtering network of the amps. The default values in the models is the correct value for a real amp.


James Freeman said:
That's wham I'm asking, why is it not internal?
To me it looks like a last moment fix.
Click to expand...
This isn't a last moment fix, this is the entire design goal of the Fractal amp modelling system. Create a platform where any amp can be modelled, but universal components are reused instead of built from scratch each time. Then different amps can be built by reusing their shared components and configuring things correctly for the amp design. The input EQ is no more a quick fix than being able to swap tonestacks, or master volume locations, or negative feedback on models. This is also why every model has all the advanced parameters. Cliff could hard code the FAT switch or transformer match ratio in each model, or he could give every model a FAT switch and knob for Transformer match ratio and let us tweak it as needed. Other platforms for the former, Cliff does the latter.

You also don't model each individual resistor when the effect of the circuit is just an EQ filter. You do model a complex circuit that is unique to a specific amp and hide that internally, but the simple EQ filter on the input of amps can be modelled as just an EQ. Then we the users get to tweak it without needing to rely on external EQ blocks too.

If it makes you feel better you can imagine as you tweak the input EQ the virtual circuit on the input of the amp is reshaping and adjusting it's components to match, and if you flatten it completely you're shorting the input jack directly to the first Triode.
 
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James Freeman said:
Still wondering why some model defaults have that and others don't.
Reason being, if the amp was modeled accurately there is no need for external quick fixes.
Click to expand...
They're not external quick fixes. In some models the low cut is exposed to the user.

For example, take the ODS-100 HRM model. In that amp there is a 390pF cap between the input buffer and the gain control. The highpass frequency is constant at 355 Hz. In this model that value is exposed to the user so they can adjust it as desired. It is common in D-style amps to tweak this value. Therefore the low-cut frequency has been exposed to the user.

In some amps, however, there is no coupling capacitor. For example, in a Deluxe Reverb the input buffer connects directly to the tone stack. In this model, therefore, the low-cut is defeated.

In other models the coupling capacitor interacts with the tone stack or the gain control and is therefore not a static value and, as such, is handled separately and not exposed to the user. For example, if a Deluxe Reverb had a coupling capacitor between the input buffer and the tone stack the low-cut frequency would be dependent upon the position of the tone controls. In this case the coupling capacitor would be handled separately and not exposed as a static frequency. Actually in this case that capacitor would be considered part of the tone stack and the network solved accordingly.
 
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FractalAudio said:
They're not external quick fixes. In some models the low cut is exposed to the user.

For example, take the ODS-100 HRM model. In that amp there is a 390pF cap between the input buffer and the gain control. The highpass frequency is constant at 355 Hz. In this model that value is exposed to the user so they can adjust it as desired. It is common in D-style amps to tweak this value. Therefore the low-cut frequency has been exposed to the user.

In some amps, however, there is no coupling capacitor. For example, in a Deluxe Reverb the input buffer connects directly to the tone stack. In this model, therefore, the low-cut is defeated.

In other models the coupling capacitor interacts with the tone stack or the gain control and is therefore not a static value and, as such, is handled separately and not exposed to the user. For example, if a Deluxe Reverb had a coupling capacitor between the input buffer and the tone stack the low-cut frequency would be dependent upon the position of the tone controls. In this case the coupling capacitor would be handled separately and not exposed as a static frequency. Actually in this case that capacitor would be considered part of the tone stack and the network solved accordingly.
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So a typical Marshall with a 22nF coupling and 1Meg gain pot network forms a 7Hz high pass, in that case the Input EQ is flat.
On a 5150+ and 5150III this network has a 470pF and 500k (1+1Meg parallel) forming a 670Hz HPF and is available as the default setting.

Got it, thank you for the clear explanation!
 
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Looking at the Stealth schematic, the Blue gain pot of 250k in parallel with the 500k network of the Red channel makes things even tighter with around 2kHz HPF.
Very interesting...
 
James Freeman said:
So a typical Marshall with a 22nF coupling and 1Meg gain pot network forms a 7Hz high pass, in that case the Input EQ is flat.
On a 5150+ and 5150III this network has a 470pF and 500k (1+1Meg parallel) forming a 670Hz HPF and is available as the default setting.

Got it, thank you for the clear explanation!
Click to expand...
Essentially.

It's not always the same. For example in a 5153 Red the coupling cap is 470pF but the low-cut frequency is dependent upon the gain control. In this case the low-cut parameter is the coupling cap off the second stage (1nF).

I tried to give the user some control over the low-end voicing whenever possible. Sometimes this is the coupling cap from the input buffer. Sometimes this is the next stage.
 
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