Free Plugin Extracts Distortion Curves from Real Gear

Black Diamond Probe is a free utility plugin from Aspen Instruments. It listens to the input and output of any distortion stage, whether hardware or software. Then, it fits a transfer curve based on that analysis.

This curve can be saved as a .tfunc file. You can load that file directly into Black Diamond Distortion, another plugin from the same developer. This lets you replicate the exact character of your favorite gear.

Key Features

The plugin includes a visualizer that shows the curve in real time. You can freeze the analysis to capture a stable reading. There are also controls for scaling the X and Y axes, plus X and Y lag settings. Mode, size, and smoothing parameters give you further adjustment options.

Black Diamond Probe is available in VST3 and AU formats. It runs on macOS 10.15 or later, Windows 10 or later, and Ubuntu 22.04 or later (x86_64). The macOS version is signed and notarized for security.

Availability

You can download Black Diamond Probe for free from the Aspen Instruments website. The latest release is v1.1.5, dated 2026-08-21. This is a standalone tool, so it does not require Black Diamond Distortion to run, but the saved curves are designed for that plugin.