This tube emulator has 8 presets emulating different tube gear and is used in production track mixing. I thought it might be interesting to optionally add a "tube buffer" into the chain for a quick A/B.
I installed the VST plugin to JRMC, measured with and without (baseline = red bottom plot) each of the 8 preset configurations.
From the measurements, they add additional 2nd order harmonic distortion of amounts up to 25dB depending on the profile selected as seen in the plot below.
They also play with the EQ profiles, volume and slightly shift phase by up to 60 degrees.
Here is another plot using the Harmonic Frequency as a reference and hiding harmonics below the noise floor. As you can see, most of the baseline is below the noise floor with the emulations are clearly above the noise floor.
