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Difference between revisions of "Drive block"

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<blockquote>"The drive block in the III uses a higher oversampling ratio and double-precision filters in some places compared to the II." [http://www.thegearpage.net/board/index.php?threads/axe-fx-iii.1907452/page-68#post-25886137] </blockquote>
 
<blockquote>"The drive block in the III uses a higher oversampling ratio and double-precision filters in some places compared to the II." [http://www.thegearpage.net/board/index.php?threads/axe-fx-iii.1907452/page-68#post-25886137] </blockquote>
  
'''Firmware Ares 3.02:'''
+
'''Firmware 3.02:'''
  
 
This firmware introduced major improvements to modeling of drive pedals. Drive models based on op-amp and diode clipping topologies were been completely overhauled. This is referred to as: FASPICE. This includes all types based on the Tube Screamer circuit.  
 
This firmware introduced major improvements to modeling of drive pedals. Drive models based on op-amp and diode clipping topologies were been completely overhauled. This is referred to as: FASPICE. This includes all types based on the Tube Screamer circuit.  
  
 
''Important: these changes result in significant changes in sound, gain and level. Tips and tricks for Drive blocks prior to firmware 3.02 may not apply anymore. Also, demos and tutorials may not represent the current tone anymore.''
 
''Important: these changes result in significant changes in sound, gain and level. Tips and tricks for Drive blocks prior to firmware 3.02 may not apply anymore. Also, demos and tutorials may not represent the current tone anymore.''
 
Firmware release notes:
 
  
 
<blockquote>"Drive models based on op-amp and diode clipping topologies have been completely overhauled in firmware 3.02 and later.
 
<blockquote>"Drive models based on op-amp and diode clipping topologies have been completely overhauled in firmware 3.02 and later.
Line 77: Line 75:
 
[https://en.m.wikipedia.org/wiki/SPICE Wikipeda]: "SPICE ("Simulation Program with Integrated Circuit Emphasis") is a general-purpose, open-source analog electronic circuit simulator. It is a program used in integrated circuit and board-level design to check the integrity of circuit designs and to predict circuit behavior."
 
[https://en.m.wikipedia.org/wiki/SPICE Wikipeda]: "SPICE ("Simulation Program with Integrated Circuit Emphasis") is a general-purpose, open-source analog electronic circuit simulator. It is a program used in integrated circuit and board-level design to check the integrity of circuit designs and to predict circuit behavior."
  
'''Firmware Ares 10:'''
+
'''Firmware 10:'''
 
 
Firmware release notes:
 
  
 
* Improved Drive block. New diode modeling algorithm improves clipping accuracy especially for diodes with higher saturation currents, i.e. 1N270 and other germanium types.
 
* Improved Drive block. New diode modeling algorithm improves clipping accuracy especially for diodes with higher saturation currents, i.e. 1N270 and other germanium types.
Line 109: Line 105:
 
* Jam Ray
 
* Jam Ray
  
'''Firmware Ares 12:'''
+
'''Firmware 12:'''
  
 
The Drive block's EQ now supports placement pre- or post-distortion.
 
The Drive block's EQ now supports placement pre- or post-distortion.
  
'''Firmware Ares 13:'''
+
'''Firmware 13:'''
  
 
<blockquote>(release notes) "Improved Drive block modeling. New algorithm uses a novel solution to solve the nonlinear ODE of a diode clipper with memory (i.e. a capacitor). The accuracy of the diode I-V curve is also greatly improved. This new algorithm has the accuracy of implicit iterative solutions with speed rivaling explicit solutions. CPU usage is only slightly increased vs. the previous algorithm. Note that many of the Drive models will now behave differently and presets should be auditioned. The behavior of the tone controls in some models has also changed. Of note are the Timmy models where the tone controls are now faithful to the actual pedal and decrease bass/treble when turned clockwise.
 
<blockquote>(release notes) "Improved Drive block modeling. New algorithm uses a novel solution to solve the nonlinear ODE of a diode clipper with memory (i.e. a capacitor). The accuracy of the diode I-V curve is also greatly improved. This new algorithm has the accuracy of implicit iterative solutions with speed rivaling explicit solutions. CPU usage is only slightly increased vs. the previous algorithm. Note that many of the Drive models will now behave differently and presets should be auditioned. The behavior of the tone controls in some models has also changed. Of note are the Timmy models where the tone controls are now faithful to the actual pedal and decrease bass/treble when turned clockwise.
Line 146: Line 142:
 
'''Firmware 19.01:'''
 
'''Firmware 19.01:'''
  
Release notes:
 
 
* Renamed Timothy and Suhr Riot Drive models to clarify switch position.
 
 
* Added Hi Mid control to Drive block.
 
* Added Hi Mid control to Drive block.
* Fixed Blackglass 7K model as reference pedal was defective. Added “Grunt” and “Attack” knobs to GUI (Grunt switch on pedal is a selectable low cut so knob duplicates Low Cut control).
 
* Changed response of Horizon Precision Drive “Attack” control to match pedal (was reversed previously). Any presets using this model should be adjusted accordingly.
 
 
* Improved accuracy of “G-taper” used for tone control in some Drive models, i.e., T808, VS9, Super OD, etc. Impact on existing presets is likely negligible but any presets using Tube Screamer models and their variants should be auditioned.
 
* Improved accuracy of “G-taper” used for tone control in some Drive models, i.e., T808, VS9, Super OD, etc. Impact on existing presets is likely negligible but any presets using Tube Screamer models and their variants should be auditioned.
 +
 +
'''Firmware 20.03:'''
 +
 +
* Improved Drive block.
 +
 +
'''Firmware 20.04:'''
 +
 +
* More Drive block improvements. Drive block now incorporates the “Chase Transform Technique” for converting analog networks to equivalent digital filters. This improves accuracy in the high frequency region.
 +
 +
'''Firmware 21.00:'''
 +
 +
* Improved Drive block modeling to more accurately model effects of op-amp finite open-loop gain and GBW product.
  
 
==Drive block and CPU usage==
 
==Drive block and CPU usage==
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==Drive block controls==
 
==Drive block controls==
  
<blockquote>"The Tone control works the same as the modeled pedal. The Bass, Mid and Treble controls are a generic EQ that can be used in addition to the Tone control to further shape the sound." [http://forum.fractalaudio.com/threads/axe-fx-ii-quantum-rev-4-01-public-beta.119924/page-45#post-1431060]</blockquote>
+
<blockquote>"The Tone control works the same as the modeled pedal." [http://forum.fractalaudio.com/threads/axe-fx-ii-quantum-rev-4-01-public-beta.119924/page-45#post-1431060]</blockquote>
  
 
<blockquote>"The model's controls replicate the actual pedal." [https://forum.fractalaudio.com/threads/analog-drive-pedals-in-front-of-axe-iii-to-get-better-feel-who-else-is-doing-this.180332/post-2204629]</blockquote>
 
<blockquote>"The model's controls replicate the actual pedal." [https://forum.fractalaudio.com/threads/analog-drive-pedals-in-front-of-axe-iii-to-get-better-feel-who-else-is-doing-this.180332/post-2204629]</blockquote>
Line 189: Line 192:
  
 
<blockquote>"Note that potentiometer tolerances can be as much as +/-20%. That means the real pedal on 5 could be equivalent to the model anywhere between 4 and 6. The same applies to the Tone and Level controls. The roll off the volume test is a good way to match the gain. Roll off the volume and if the model has less gain increase the gain control and vice-versa." [https://forum.fractalaudio.com/threads/video-boss-sd-1-vs-axe-fx-iii-super-od-sd-1.182128/post-2236354]</blockquote>
 
<blockquote>"Note that potentiometer tolerances can be as much as +/-20%. That means the real pedal on 5 could be equivalent to the model anywhere between 4 and 6. The same applies to the Tone and Level controls. The roll off the volume test is a good way to match the gain. Roll off the volume and if the model has less gain increase the gain control and vice-versa." [https://forum.fractalaudio.com/threads/video-boss-sd-1-vs-axe-fx-iii-super-od-sd-1.182128/post-2236354]</blockquote>
 +
 +
About the tone controls on the Tone page:
 +
 +
<blockquote>"It used to read -12 to +12 dB. Now it reads 0 to 10. The response is the same EXCEPT for the BB Preamp, AC Boost and RC Boost models. For those models the bass and treble response behaves the same as the real pedal. Therefore for all but the aforementioned models 0 = -12 dB, 5 = 0 dB and 10 = +12 dB." [https://forum.fractalaudio.com/threads/new-drive-format-question.186138/post-2302378]</blockquote>
  
 
==EQ==
 
==EQ==
Line 211: Line 218:
  
 
<blockquote>(firmware 4.00 for the Axe-Fx III) "Duplicating the behavior of a fuzz pedal requires that the pedal be the first non-bypassed block following the Input 1 block and the input block impedance must be set to Auto since fuzz pedals load down the guitar’s pickups."</blockquote>
 
<blockquote>(firmware 4.00 for the Axe-Fx III) "Duplicating the behavior of a fuzz pedal requires that the pedal be the first non-bypassed block following the Input 1 block and the input block impedance must be set to Auto since fuzz pedals load down the guitar’s pickups."</blockquote>
 +
 +
<blockquote>
 +
"The physical interaction between the pickups and the circuit is difficult to recreate because the pickups are an unknown quantity." [https://forum.fractalaudio.com/threads/what-could-still-be-improved.186167/post-2305651]
 +
</blockquote>
  
 
Forum member AustinBuddy recommends setting Input Impedance to 90K in presets which have a fuzz model as the very first (non-bypassed) block. This doesn't apply to processors with a fixed input impedance.
 
Forum member AustinBuddy recommends setting Input Impedance to 90K in presets which have a fuzz model as the very first (non-bypassed) block. This doesn't apply to processors with a fixed input impedance.
Line 342: Line 353:
 
==BB Pre (BB preamp)==
 
==BB Pre (BB preamp)==
  
Models this Xotic overdrive that has a preamp stage
+
Models version 1.5 of this Xotic overdrive that has a preamp stage
  
 
[[file:x_BB.jpg|100px]]
 
[[file:x_BB.jpg|100px]]
 +
 +
==BB Pre AT (BB preamp Andy Timmons edition)==
 +
 +
Based on the original BB preamp (before 1.5)
  
 
==Bender Fuzz (Tone Bender)==
 
==Bender Fuzz (Tone Bender)==
Line 411: Line 426:
  
 
[[file:x_RC.jpg|100px]]
 
[[file:x_RC.jpg|100px]]
 +
 +
==Esoteric Bass RCB (Bass RC Booster)==
 +
 +
Models Xotic's boost pedal for bass
  
 
==Eternal Love (Eternity)==
 
==Eternal Love (Eternity)==
Line 453: Line 472:
  
 
[[file:x_FD2.jpg|170px]]
 
[[file:x_FD2.jpg|170px]]
 +
 +
==Griddle Cake (Hot Cake)==
 +
 +
Paul Crowther's overdrive from New Zealand makes a great match with VOX amplifiers
  
 
==Hard Fuzz (custom model)==
 
==Hard Fuzz (custom model)==

Revision as of 08:40, 22 October 2022

Contents

350px

The Drive block

Available on which products

  • Axe-Fx III: 4 blocks
  • FM3: 2 blocks
  • FM9: 3 blocks
  • Axe-Fx II: 2 blocks
  • AX8: 2 blocks
  • FX8: 2 blocks

Channels or X/Y switching

  • Axe-Fx III and FM9 and FM3: 4 channels
  • Axe-Fx II: X/Y
  • AX8: X/Y
  • FX8: X/Y

About drive modeling

Yek's Guide to the Fractal Audio Drive models

Forum member Yek has written a guide (PDF) that covers all the models in detail. Click on the image below.

Yeks Drives Guide.png

Pictures of the modeled pedals

Gallery of modeled pedals, by forum member MDProd

Factory presets

Many factory presets have one or more Drive blocks. Search the Factory presets page.

Modeling improvements

"The drive block in the III uses a higher oversampling ratio and double-precision filters in some places compared to the II." [1]

Firmware 3.02:

This firmware introduced major improvements to modeling of drive pedals. Drive models based on op-amp and diode clipping topologies were been completely overhauled. This is referred to as: FASPICE. This includes all types based on the Tube Screamer circuit.

Important: these changes result in significant changes in sound, gain and level. Tips and tricks for Drive blocks prior to firmware 3.02 may not apply anymore. Also, demos and tutorials may not represent the current tone anymore.

"Drive models based on op-amp and diode clipping topologies have been completely overhauled in firmware 3.02 and later.

For many types there is now a “Dry Gain” control. This parameter controls the amount of “dry” signal mixed with the “wet” (distorted) signal. For a Tube Screamer-based model this will default to 100% due to the topology. For other types this will default to 0. Values up to 200% are allowed. Note that the dry data is added before any tone controls and therefore is not exactly equivalent to a mix but rather replicates the behavior of analog circuits.

Drive types based on op-amp and diode clipping circuits now allow control over the type and quantity of diodes in the positive and negative polarity. For example, the user can select (2) 1N34A diodes for positive signal polarity and (1) red LED for negative. Experiment with the various diode types and quantities to obtain new and unique sounds.

The Basic GUI page now reflects only the controls found on the actual pedal. In cases where the actual pedal does not have any tone controls a simple Tone control is included for convenience."

The tone circuits of ALL drive types have been updated in firmware Ares 3.02 and later, and all models have been rematched to the original pedals. [2] [3]

The changes do not apply to the input boosts in the Amp block. [4]

More about FASPICE:

"New Drive block algorithm (FASPICE) implemented and working." [5]

"I've "cracked the code" on drive pedals and figured out a way to do a SPICE simulation in real time without using gobs of CPU. It's so simple I can't believe no one ever thought of it before but none of the papers even approach anything resembling the technique. This will bring "Ares" level modeling to the Drive block." [6]

"This algorithm applies to a particular set of circuits that incorporate diodes as a nonlinear component. SPICE modeling is particularly slow when modeling diodes due to convergence issues. However the diodes in drive pedals are used in such a way that there's a trick that can be employed to dramatically decrease the amount of CPU needed to simulate the circuit." [7]

"It normally takes a lot of CPU power to do a real-time simulation. The amp block uses an entire dedicated DSP. To do even a simple distortion pedal would normally require huge amounts of CPU. But I stumbled upon a simple trick that reduces it dramatically." [8]

(picture) "See the two diodes, D1 and D2? The type and quantity of these diodes (among other things that I can't reveal) affect the tone. D1 is the "negative" diode. It conducts when the voltage is negative. D2 is the "positive" diode. It conducts when the voltage is positive. In this schematic the diodes are listed as 1N34A but in the original Distortion+ they were actually 1N270. If you select the Plus Dist model and go to the last page in the UI you'll see the type of diode is 1N270. You can change the type and quantity which will change the distortion characteristics.

1N270 and 1N34A are Germanium diodes. They have a greater reverse saturation current (Is) and, hence, a lower forward voltage for a given current. This means they clip sooner. Silicon diodes, i.e. 1N4148, 1N916, etc. have a lower Is and a greater forward voltage. LEDs have yet a greater forward voltage (smaller Is).

This new firmware has 16 diode SPICE models that I collected from various sources that you can play with. 1N914 are often substituted for 1N4148 and vice-versa but they are slightly different so I included both. The original Tube Screamer had 1S1588 which, to my ears, are much different (better) sounding than 1N914 which are used in the newer Tube Screamers." [9]

Wikipeda: "SPICE ("Simulation Program with Integrated Circuit Emphasis") is a general-purpose, open-source analog electronic circuit simulator. It is a program used in integrated circuit and board-level design to check the integrity of circuit designs and to predict circuit behavior."

Firmware 10:

  • Improved Drive block. New diode modeling algorithm improves clipping accuracy especially for diodes with higher saturation currents, i.e. 1N270 and other germanium types.
  • Added D9E and D18 diode models to Drive block. These are Soviet germanium diodes valued for their smooth distortion characteristics.

"Firmware 10 uses new "FASPICE XD" modeling in the amp and drive block. It requires a bit more CPU but the accuracy is far better. I figured out a way to ensure that transcendental equations are always stiffly stable and converge in a fixed amount of time. Significantly faster and at least as accurate as trapezoidal, modified trap, gear, etc. algorithms. It dampens numerical ringing without the side-effect of damping actual circuit ringing. Once you see how it works it seems hard to believe that no one has thought of it before but I can't find a single paper or article that uses the technique. The only drawback is that frequency response is limited to about 1/2 Nyquist but since we oversample that's irrelevant. So that's why you get the "amp feels like it's going to explode" but without the noise and artifacts." [10]

The affected Drive models are: ([11])

  • Rat
  • Super OD
  • T808 OD
  • Fat Rat
  • Plus Distortion
  • Full OD
  • Blues OD
  • Shred Distortion
  • M-Zone Distortion
  • BB Pre
  • Eternal Love
  • Esoteric ACB
  • Esoteric RCB
  • Zen Master
  • FAS LED-Drive
  • Ruckus
  • FAS Boost
  • Timothy
  • Tone of Kings
  • Heartpedal 11
  • Jam Ray

Firmware 12:

The Drive block's EQ now supports placement pre- or post-distortion.

Firmware 13:

(release notes) "Improved Drive block modeling. New algorithm uses a novel solution to solve the nonlinear ODE of a diode clipper with memory (i.e. a capacitor). The accuracy of the diode I-V curve is also greatly improved. This new algorithm has the accuracy of implicit iterative solutions with speed rivaling explicit solutions. CPU usage is only slightly increased vs. the previous algorithm. Note that many of the Drive models will now behave differently and presets should be auditioned. The behavior of the tone controls in some models has also changed. Of note are the Timmy models where the tone controls are now faithful to the actual pedal and decrease bass/treble when turned clockwise.

The Drive block now features a “Bass Response” control for types based on the Rat, Tube Screamer and various derivates. In some models this is duplicated on the Basic page as it is the Bass/Voice/etc. control (and renamed accordingly). This function was previously provided by the Low Cut control. The Low Cut control is now a separate control that allows adjusting the input highpass frequency. Existing presets will automatically be updated with the new default value for the Low Cut control.

Added Bias control to GUI of all Drive block models."

More information

From a forum thread:

"It solves the nonlinear ODE using a novel technique."

"Personally I think it's noticeably better. I never used Drive blocks before and now I use them occasionally."

"They sound more "analog" and feel better. The old algorithm is the classic filter->waveshaper->filter technique. It's okay but I've long moved beyond waveshapers in amp modeling so it was time to do that in the drive block."

"We completely redid the drive block using a novel technique for solving the nonlinear ODE that you get with a resistor/diode/capacitor that's used in 99% of drive pedals. It results in much improved sound and feel." [12]

The changes in firmware Ares 13 for the Axe-Fx III were ported to firmware 3.03 (and later) for the FM3, including all drive types.

Firmware 17:

"Added 1S1588T diode SPICE model to Drive block. This is the Toshiba version of the 1S1588 and is reportedly the diode used in the “best sounding” TS-808s. The T808 OD models have been updated to use this diode. Existing presets are unchanged."

"Added “Valve Screamer VS9” and "Maxoff 808" Drive models."

Improved accuracy of Drive block Drive control for low settings.

Firmware for the FM3 and FM9 included the same improvements.

Firmware 19.01:

  • Added Hi Mid control to Drive block.
  • Improved accuracy of “G-taper” used for tone control in some Drive models, i.e., T808, VS9, Super OD, etc. Impact on existing presets is likely negligible but any presets using Tube Screamer models and their variants should be auditioned.

Firmware 20.03:

  • Improved Drive block.

Firmware 20.04:

  • More Drive block improvements. Drive block now incorporates the “Chase Transform Technique” for converting analog networks to equivalent digital filters. This improves accuracy in the high frequency region.

Firmware 21.00:

  • Improved Drive block modeling to more accurately model effects of op-amp finite open-loop gain and GBW product.

Drive block and CPU usage

The Drive models take up various amounts of CPU. The numbers are listed in Yek's Guide to the Fractal Audio Drive models (PDF).

CPU usage is amplitude dependent on the Axe-Fx II, AX8 and FX8. This means that CPU usage will change when you hit the strings (even with the Drive block in bypassed state). This does not apply to the Axe-Fx III and FM3.

Drive models in firmware Ares 3.02 and later require somewhat less CPU (1-2%) than before. Diode-based models in firmware Ares 13 and later require more CPU.

Drive types as input boosts in the Amp block

Some of the Drive models are available as input boosts in the Amp block. Read this: Input Boost

Distortion in the Cab block

The Cab block's Preamp page provides tools to simulate the distortion from mic preamps, channel strips and tape.

Dynamic Distortion

Read this

Drive block controls

"The Tone control works the same as the modeled pedal." [13]

"The model's controls replicate the actual pedal." [14]

In firmware Ares 3.02 and later, the basic GUI page reflects only the controls found on the actual pedal. In cases where the actual pedal does not have any tone controls, a simple Tone control is included for convenience.

(firmware Ares 13) "The Drive block now features a “Bass Response” control for types based on the Rat, Tube Screamer and various derivates. In some models this is duplicated on the Basic page as it is the Bass/Voice/etc. control (and renamed accordingly). This function was previously provided by the Low Cut control. The Low Cut control is now a separate control that allows adjusting the input highpass frequency. Existing presets will automatically be updated with the new default value for the Low Cut control."

Firmware 19.01 for the Axe-Fx III and later added the Hi Mid control.

"Note that potentiometer tolerances can be as much as +/-20%. That means the real pedal on 5 could be equivalent to the model anywhere between 4 and 6. The same applies to the Tone and Level controls. The roll off the volume test is a good way to match the gain. Roll off the volume and if the model has less gain increase the gain control and vice-versa." [15]

About the tone controls on the Tone page:

"It used to read -12 to +12 dB. Now it reads 0 to 10. The response is the same EXCEPT for the BB Preamp, AC Boost and RC Boost models. For those models the bass and treble response behaves the same as the real pedal. Therefore for all but the aforementioned models 0 = -12 dB, 5 = 0 dB and 10 = +12 dB." [16]

EQ

The non-graphic EQ comes after the gain (post). The Low Cut is pre-gain. High Cut is post. The graphic EQ is selectable.

Preventing phase issues

When adding a Drive block to a preset with two Amp blocks in parallel rows, make sure to put the the Drive block before the rows split, or add a Drive block to each row, to prevent phase issues.

Fuzz, buffers and impedance

Many fuzzes depend on a direct connection between the guitar pickup and the input of the pedal. A modeler gets in the way because its input is always buffered. This means that a modeled fuzz will react differently than the actual pedal.

"The Fuzz in the Axe-Fx reacts as though there is a buffer in front of it (because there is). It's a limitation inherent to all modeling products. I modeled it using a nominal source resistance. I forget what I used for the source resistance but it was probably around 100K ohms. To really simulate it you would need a controller to simulate the changing output impedance of the guitar." [17]

"You can simulate the effect of a guitar into a Fuzz-Face using the Input-Z feature." [18]

"The problem is that the signal is buffered and there is no way to model the interaction of the pickups with the circuit." [19]

"It's impossible to get a buffered device (like a multi-effect) to replicate fuzz pedals because the input impedance of a fuzz pedal is nonlinear. You can get close by using a static input resistance at the input to the device but it will never be exactly the same. [20]

(firmware 4.00 for the Axe-Fx III) "Duplicating the behavior of a fuzz pedal requires that the pedal be the first non-bypassed block following the Input 1 block and the input block impedance must be set to Auto since fuzz pedals load down the guitar’s pickups."

"The physical interaction between the pickups and the circuit is difficult to recreate because the pickups are an unknown quantity." [21]

Forum member AustinBuddy recommends setting Input Impedance to 90K in presets which have a fuzz model as the very first (non-bypassed) block. This doesn't apply to processors with a fixed input impedance.

Read this: Input impedance

Tips and tricks

Tighten the tone with a Drive block or Input Boost

A Drive block before the Amp block, with minimal gain, will tighten the low end of dirty amp tones. It also allows turning down gain in the Amp block. This works well in particular with Tube Screamer-based Drive types.

Alternatively, use a PEQ block, set to Blocking, copying High Cut and Low Cut values from a favorite Drive type. This will apply the same coloring as the drive, without the gain and CPU usage.

Firmware Ares and later also provides Input Boost types in the Amp block itself, see above.

Turn an Amp block into a Drive

Insert a second Amp block before the main Amp block, turn off its power amp simulation, and you have changed the amp model into a preamp / drive model. Set the main Amp block to a fairly clean tone for best results. Try this with these models: Euro Blue/Red/Uber, Friedman BE, Dizzy, 5153.

More information:

Add gain to high single notes with the Pitch Detector

Attach Pitch (internal controller) to the Drive parameter and use Slope in the modifier menu to fine-tune. This will add gain to single notes when played high on the neck.

More information:

Use a Drive type to warm up or soften a Synth sound

A Drive type, especially the RAT, is often used (in front of the Synth block) to warm up or often a synth tone.

Use Tape Distortion to add vintage flavor

The Tape Distortion, either before or after the Amp block, can add a vintage flavor to the sound.

Emulating other drives and devices

Note: because of ever evolving firmware, the suggested settings in the links below may not be accurate.

Earlier FAS products do not have a model of a Klon Centaur boost/overdrive pedal. Here are ways to approach its sound:

Videos

Leon Todd demos new Drive types

Parameters

Mix

Unlike other effect blocks, Mix at 0% in a Drive block is not equivalent to 100% dry signal ("True Bypass").

"The models let clean through even with the mix at 100%. It depends on the diodes though as to how much clean is mixed. Our models are based on the most common versions." [22]

"The mix control in the Drive block controls the ratio of clean to dirty in the distortion stage. It's not the same as the standard mix control in the other effects." [23]

The Mix control operates prior to any tone control. This lets you mix some dry in with the distorted signal but still maintain overall tone control.

Some players like to turn down the effects’s Mix level (80% or lower) to increase transparency and decrease buzziness.

Note that Mix is different from the Dry Level parameter in diode/opamp-based drive types (see below).

Sample Rate

Use Sample Rate Reduction to intentionally allow aliasing, for creative effects.

Bass Response and Low Cut

Firmware Ares 13 changed the functionality of Low Cut and has added the Bass Response control.

“The Drive block now features a “Bass Response” control for types based on the Rat, Tube Screamer and various derivates. In some models this is duplicated on the Basic page as it is the Bass/Voice/etc. control (and renamed accordingly). This function was previously provided by the Low Cut control. The Low Cut control is now a separate control that allows adjusting the input highpass frequency. Existing presets will automatically be updated with the new default value for the Low Cut control.”

Bit Reduce

Use Bit Reduction to intentionally lower the resolution of the signal, for creative effects.

Slew Rate / Slew Limit

This probably refers to how fast the circuit can swing its output. If the signal to be amplified is too fast, the circuit will not be able to perform properly, only amplifying signals below the slew rate limit. Poor slew rate results in high frequencies not passing through the amplifier, and thereby limiting or muting high harmonics.

The Pro Co RAT is known for its poor slew rate, because of the LM308 op-amp being used. Read this

Explanation of Slew Rate in Wikipedia:

  • "In electronic musical instruments, slew circuitry or software-generated slew functions are used deliberately to provide a portamento (also called glide or lag) feature, where an initial digital value or analog control voltage is slowly transitioned to a new value over a period of time (see interpolation)"
  • "Slew-induced distortion (SID or slew-rate induced distortion) is caused when an amplifier or transducer is required to change output (or displacement), i.e. slew rate, faster than it is able to do so without error. At such times any other signals may suffer considerable gain distortion, leading to intermodulation distortion. Transient intermodulation distortion may involve some degree of SID and/or distortion due to peak compression"

Explanation of Slew-induced distortion in Wikipedia:

  • "Slew-induced distortion (SID or slew-rate induced distortion) is caused when an amplifier or transducer is required to change output (or displacement), i.e. slew rate, faster than it is able to do so without error. At such times any other signals may suffer considerable gain distortion, leading to intermodulation distortion.[1] Transient intermodulation distortion may involve some degree of SID and/or distortion due to peak compression"

Firmware Ares 10.01:

"Changed Drive block Slew Limit to Slew Rate and updated default value of the models. Existing presets will be updated to the new default value upon recall. Note that the parameter now controls the slew rate and lower values equal less high frequency response at high amplitudes and vice-versa (the action is reversed from the previous firmware versions)."

Graphic EQ

The 10-band Graphic EQ was added in firmware Ares and later.

The EQ is reset when changing the Drive type.

In firmware Ares 12 and later the EQ can be placed either PRE or POST distortion.

Dry Level

Even with Mix at 100%, clean level can pass through diodes. The Dry Level parameter in diode/opamp-based drive types (in firmware Ares 3.02 and later for the Axe-Fx III) determines the amount of clean level that passes through the diodes.

Release notes Ares 3.02:

"This parameter controls the amount of “dry” signal mixed with the “wet” (distorted) signal. For a Tube Screamer-based model this will default to 100% due to the topology. For other types this will default to 0. Values up to 200% are allowed. Note that the dry data is added before any tone controls and therefore is not exactly equivalent to a mix but rather replicates the behavior of analog circuits."

"If the Dry defaults to 100 then it's a Tube Screamer derivative. Tube Screamers use a non-inverting op-amp configuration with diodes in the feedback loop. This results in a transfer function that is Y = X + f(X) where f(X) is the distortion response. IOW they mix the dry signal with a distorted signal."

Drive models

BB Pre (BB preamp)

Models version 1.5 of this Xotic overdrive that has a preamp stage

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BB Pre AT (BB preamp Andy Timmons edition)

Based on the original BB preamp (before 1.5)

Bender Fuzz (Tone Bender)

Models the Sola Sound/Vox fuzz that Jimmy Page used to record "Whole Lotta Love"

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Bit Crusher (custom model)

Custom model, which warms up a sound or deliberately degrades a signal by reducing number of bits or sample rate

Blackglass B7K (Microtubes B7K)

Models the analog bass preamp from Darkglass, famous for its overdrive and transparency

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Blues OD (Bluesbreaker (Mk1)

Models the Marshall Bluesbreaker pedal, Mk I, which produces the mildly overdriven valve sound of the 2x12 Marshall combo amp, used by Eric Clapton in John Mayall’s Bluesbreakers

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Box o'Crunch (Crunch Box V1)

Models this popular "Marshall-in-a-box" pedal from MI Audio

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Compulsion Distortion LP (OCD)

Models the popular Fulltone "Obsessive Compulsive Drive" OCD pedal, in Low Peak mode

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Compulsion Distortion HP (OCD)

Models the popular Fulltone "Obsessive Compulsive Drive" OCD pedal, in High Peak mode

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DS1 Distortion (DS-1 Distortion)

Models the popular BOSS distortion pedal, used by Steve Vai, Joe Satriani, Kurt Cobain

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DS1 Distortion Mod (modded DS-1 Distortion)

Models a modded version of the BOSS DS-1

"I didn't model it based on any actual pedal. I made the model by taking the DS-1 and applying the Keeley "Seeing Eye" and "Ultra" mods." [24]

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Esoteric ACB (AC Booster)

Models the thick, light-to-medium overdrive ("Almost Clean") from Xotic

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Esoteric RCB (RC Booster v1)

Models the Xotic "Real Clean" transparent boost pedal

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Esoteric Bass RCB (Bass RC Booster)

Models Xotic's boost pedal for bass

Eternal Love (Eternity)

Models this clean boost, overdrive and treble booster from Lovepedal

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FAS Boost (custom model)

A custom model, designed to boost vintage amps like Plexis

FAS LED-Drive (custom model)

Models LED clipping

FET Boost (custom model)

Models gentle and smooth FET clipping

FET Preamp (custom model)

Models a FET preamp, possibly similar to BOSS' FA-1 FET Amplifier.

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Face Fuzz (Fuzz Face)

Models the Dallas Arbiter fuzz that Jimi Hendrix used

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Fat Rat (modded RAT)

Models this modded version of the RAT that sounds fuller and smoother

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Full OD (Full-Drive 2)

Models this thicker and darker variant of the Tube Screamer, from Fulltone

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Griddle Cake (Hot Cake)

Paul Crowther's overdrive from New Zealand makes a great match with VOX amplifiers

Hard Fuzz (custom model)

Creates a hard-clipping, 60s-style fuzz

Heartpedal 11 (OD11/Amp Eleven)

Models the Lovepedal pedal that sounds like an overdriven tube amp

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Hoodoo Drive (Voodoo Lab Overdrive)

Models this vintage overdrive

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Horizon Precision Drive (Precision Drive)

Models the Horizon Devices pedal that sculpts metal and djent tones

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Jam Ray (Jan Ray)

Models the boutique boost/overdrive from Vemuram which replicates the tone of driven blackface Fender amps from the '60s

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Klon Chiron (Klon Centaur)

Models the most boutique (expensive) boost/overdrive ever

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M-Zone Distortion (MT-2 Metal Zone)

Models this classic pedal from BOSS which gets crushing metal tones from any amp, love it or hate it

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MCMLXXXI DRV (1981 Inventions DRV)

Models this Pro Co RAT clone with different pre-distortion shaping

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Master Fuzz (Maestro Fuzz-Tone FZ-1A)

Models the original Maestro fuzz pedal, used in "(I Can't Get No) Satisfaction"

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Maxoff 808 (Maxon OD-808)

Models the Maxon OD-808 overdrive, a close replica of the original Ibanez TS9 Tube Screamer, but smoother and with less midrange honk

"Maxon sounds a bit different due to the different op-amp and diodes. Smoother and less midrange honk." [25]

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Micro Boost (Micro Amp)

Models this popular MXR clean boost from the '80s

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Mid Boost (custom model)

A custom model that boosts the middle frequencies

OD 250 (Overdrive Preamp 250)

Models the reissue of this DOD overdrive that pushes an already driven amp

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OD 250 Gray (Overdrive Preamp 250)

Models the original gray version of the DOD overdrive

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Octave Distortion (Octavia)

Models the well-known octave-up fuzz from Tycobrahe, made famous by Jimi Hendrix

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PI Fuzz (Big Muff Pi Triangle)

Models the famous saturated fuzz from Electro-Harmonix

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Plus Distortion (Distortion +)

Models this old MXR distortion box which gets more distortion from an already overdriven amp

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Rat Distortion (RAT)

Models Pro Co's famous black distortion box

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SDD Preamp (Korg SDD-3000 preamp)

Models the preamp in Korg's rackmount SDD-3000 digital delay, used by The Edge

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Shimmer Drive (custom model)

Custom model, designed to boost models of vintage non-Master amps (Plexi, Vox, Fender)

Shred Distortion (Shred Master)

Models Marshall's distortion pedal for shredders

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Sonic Drive (Sonic Distortion SD-9)

Models the distortion pedal from Ibanez that's popular among fusion players

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Suhr Riot Ge (R) (Riot)

Models Suhr's amp-in-a-box pedal, set to Germanium voicing (switch to the right)

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Suhr Riot LED (L) (Riot)

Models the pedal set to LED voicing (switch to the left)

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Suhr Riot LED/Si (M) (Riot)

Models the pedal set to hybrid LED/Silicon Diode voicing (switch in the middle)

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Super OD (SD-1 Super OverDrive)

Models the competitor from Boss to the Tube Screamer, popular with high gain players

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T808 Mod (modded TS-808 Tube Screamer)

Models a modded TS-808 for more bass, more gain, more transparency

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T808 OD (TS-808 Tube Screamer)

Models the venerable Ibanez TS-808 Tube Screamer

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TS9DX + (TS9DX Turbo Tube Screamer)

Models the Ibanez Turbo Tube Screamer in Plus-mode

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TS9DX Hot (TS9DX Turbo Tube Screamer)

Models the Ibanez Turbo Tube Screamer in Hot mode

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Tape Distortion (tape distortion)

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Models the clipping of an overdriven reel-to-reel Ampex tape deck

Timothy Down (Timmy)

Models this popular transparent boost/overdrive pedal (blue), designed by Paul Cochrane, with the clipping mode switch set to bottom position (symmetrical clipping, less headroom/diodes)

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Timothy Mid (Timmy)

Clipping mode switch in middle position (symmetrical clipping)

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Timothy Up (Timmy)

Clipping mode switch in top position (asymmetrical clipping)

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Tone of Kings (King of Tone)

Models this sought-after variant on Marshall's Bluesbreaker pedal from Analog Man

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Treble Boost (silicon treble booster circuit)

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Models a silicon-based treble booster

Tube Drive 3-knob (Tube Driver)

Models the version of this pedal (which has a 12AX7 tube inside) with 3 knobs

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Tube Drive 4-knob (Tube Driver)

Models the version of this pedal (which has a 12AX7 tube inside) with 4 knobs, used by Eric Johnson

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Valve Screamer VS9 (Tube Screamer TS9)

Models the famous original Ibanez TS9 Tube Screamer

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Zen Master (Zendrive)

Models the famous "Dumble-in-a-box" pedal, used by Robben Ford

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