Saturation and Dynamics.

From subtle to strong level-independent processing.

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- mono/stereo

- several circuits

- tube modeling

- level-independent dynamics

- level-independent dynamic filters

- dynamic saturation

video1 (drums)

video2 (guitar)


Please request the format you need with your payment

(Win 32/64 bit, Mac VST/AU/32/64 bit)



(click to enlarge)

Grasso effect

Grasso is a complete saturation and dynamics unit.

It is NOT a compressor, no thresholds.

It is NOT an envelope shaper, no triggering.

Is includes some special features like level-independent dynamics, tube-saturation stage, dynamic and level-independent pre-drive filtering, spank control and a modeled power-supply.

It is very useful to add color and dynamic control to mixes and single tracks, from subtle to extreme.

Main features:

  • tube-modeling

  • level-independent dynamics

  • level-independent dynamic filtering (on attack and decay)

  • detailed control on tube circuits with several options

  • "spank" feature (post-drive dynamic response)

  • modeled "weak" power supply (more harmonics or "sagging")

  • special post drive expander for great dynamics

Available as Win32/64 VST, Mac32/64 VST/AU and soon RTAS/AAX



upper band: input level post-EQ (to saturation stage)

lower band: peak saturation

Note: the lower band doesn't show the amount of distortion added to the incoming signal, it is related to the overall compression added by saturation. It can be compensated by means of the "dynamics" control. The value shown by the meter corresponds to the true compression when "dynamics" control is at zero.


Input gain


Two bands of pre-drive peak-equaliser. Control saturation control and harmonics.

Freq: center frequency

Gain: band gain

EQ mode (menu)

Static: a static equaliser

Peak: acts on peaks only (clean decay)

Decay: acts on decay only (clean peaks)


Overall control on selected tube model behavior.

Lower values: saturates at high levels and generates less high harmonics on peaks

Higher values: more harmonics and a brighter sound

Note: it is not a brightness control. It affects the whole dynamic spectrum


Overall control on tube model dynamics, from faster to slower. Useful on sustained and dynamic sounds like a guitar


A level-independent control on attack level.

Center position: attack unaffected

Lower values: attack level reduced

Higher values: attack level increased

Note: reduce attack level to move the source far from the listener. Increase to add dynamics.

Note: affected by "snap" control


Affects the overall time constants of the dynamic controls.

Lower values: faster attack (look for the "snap" sweet spot)

Higher values: slower attack (fatter, punchier and higher attacks)


A level independent control on decay duration.

Center position: decay unaffected

Lower values: decay duration reduced

Higher values: decay duration increased

Note: increase decay duration to move the source far from the listener. Decrease to make it dry and closer to the listener.

Note: Decrease attack level and increase decay time for a big room (if the source isn't gated)


This is a control on the behavior of tube circuits on strong peaks.

Spank sets the amount of effect, from dry to max.


Coarse control on the color of the spank effect (dynamic resonance)


Output gain


Available power for the emulated power supply.

Max value: infinite power (disabled feature)

Lower values: the power supply introduces saturation, more harmonics and a weak output to strong signals.

Note: lower values strongly interact with "color" knob.