DDMF Tube Preamp

Circuit-modeled analog saturation effect developed by Philipp Bulling (aka phi-L Audio).

Tube Preamp emulates the distortion characteristics of an analog tube amplifier while letting the user customize the simulated tube circuit. 

Tube Preamp stands out as one of the most “tweakable” saturation plugins on the market. You can manually adjust and fine-tune almost every virtual component of the modeled tube circuit.

The user can quite easily edit the values of the simulated capacitors, resistors, and other components. Each component is controlled by a tiny knob that directly adjusts its value.

https://ddmf.eu/phi-L-Audio-Tube-Preamp/

ATKBassPreamp

ATKBassPreamp is a bass preamp plugin, modeling the inverter input stage of a Fender Bassman followed by its tone stack.

The plugin is built with Audio TooKit and JUCE.

http://blog.audio-tk.com/2017/05/23/announcement-atkbasspreamp-1-0-0/

Musicrow Preamp

Preamp Emulator emulates the way tube preamps behave and sound. It will add the typical saturation and warmth of real tubes to your digital tracks!

Preamp emulator is very easy to use, and there are only a few parameters for you to handle: input level, tube drive amount, tube type selection, output level and a power switch.


http://mcrow.net/product/preamp-vst-emulator/

SGA 1566

Shattered Glass Audio has released SGA1566, a free plug-in for Mac OS X and Windows in AU and VST plug-in formats.

SGA1566 is designed to deliver the sonic beauty of a two stage, all tube, preamp using circuit simulation technology. SGA1566 is loosely based on a single channel vintage tube preamplifier. To achieve the most authentic analog sound, the whole circuit is simulated in real time using the high performance circuit simulator. This level of sound fidelity comes at a price of high CPU utilization. For cases where such a CPU hit is prohibitive, SGA have added a model that is significantly less CPU intensive but only slightly less accurate than the circuit simulation.

Use SGA1566 preamp to add warmth to a track, as a saturation compressor, or to add "dirt" with tube overdrive.

http://www.shatteredglassaudio.com/gear_list.php?id=digital