In the realm of guitar plugins, where everyone seeks their perfect sound, SoftAmp PSA by AXP emerges as a powerful contender, offering a virtual emulation of legendary guitar hardware that needs no introduction. This plugin isn’t just another amplifier emulator; it’s a meticulously modeled preamp, complete with useful tools like a noise gate and compressor, making it a versatile solution for shaping your guitar tone directly within your digital audio workstation.
The Heart of the Sound: SoftAmp PSA Virtual Preamp
At the core of SoftAmp PSA lies a sophisticated virtual-analog engine that accurately replicates the behavior of classic guitar equipment. Rather than simply layering effects, the plugin simulates non-linear filters whose output depends on both the frequency and amplitude of the input signal. This provides a more realistic and dynamic sound compared to simplified approaches.
Multi-Stage Distortion and Tone Shaping
SoftAmp PSA is equipped with five stages of distortion, each with unique characteristics for shaping the frequency response:
- The first three stages are based on operational amplifiers with Zener diodes in the feedback loop.
- The last two stages are operational amplifiers operating in saturation mode.
After the distortion stages, the signal passes through a tone stack, a cabinet emulator (speaker), and an output level control. Each distortion stage has its own character, reflected in its name, and you can visualize their impact on the frequency response using the built-in EQ graph.
Deep Control and Unique Features
In addition to the basic controls, SoftAmp PSA offers advanced settings for fine-tuning your sound:
- Shape and Rolloff: Two controls for adjusting the parameters of the speaker emulator. Setting both to 0 completely disables cabinet emulation, which is useful when using external impulse responses.
- Asymmetric: This feature is applied to stages with Zener diodes and replaces the standard 4.7v/4.7v diode pair with an asymmetric 3.3v/4.7v pair. This intentionally unbalances the signal, adding even-order harmonics, which makes the sound richer. The more overloaded the first three stages are, the more pronounced this effect is. Clipping indicators help track which stage is receiving the most saturation.
- Soft-Clip: The “Soft Clipping” function applies to the two overloaded operational amplifiers. It reduces their open-loop gain from a value of a million to 200. This makes the transition from the linear region to saturation much smoother, reducing the harshness of the distortion and helping the decaying notes sound smoother.
Additional Tools: PSI Denoiser and Squeezo Range
SoftAmp PSA integrates two useful tools for further refining your guitar signal:
- PSI Denoiser (Noise Gate): Applied directly to the input signal. Has a convenient “Learn” feature. Don’t play the guitar, press the Learn button, and as soon as the LED goes out, the gate threshold will be automatically set to your noise level.
- Squeezo Range (Compressor): Located directly before the PSA preamp input. It’s a highly non-linear, yet musically sounding device. It can function as either an upward or downward compressor, depending on the Gain and Bias settings, although these controls were not available to the user in the original equipment.
SoftAmp PSA by AXP isn’t just a plugin, it’s a complete tool for guitarists seeking authentic analog sound with flexible digital capabilities. Its detailed emulation, multi-stage distortion, advanced settings, and integrated tools make it a valuable addition to any virtual studio.
Try SoftAmp PSA to discover new facets of your guitar’s sound!
