AudioThing has released Valve Exciter, a VST/AU plug-in for 32- and 64-bit Mac OS X and Windows.
Valve Exciter is a Harmonic Enhancer plug-in with vintage valve emulation. The exciter section features hand tuned filters with the ability to sweep the center frequencies via the Harmonics knob. The valve section is modelled after a softer custom version of the vintage Telefunken ECC83 tubes with drive, triode/pentode mode and bias settings.
Specifications:

• Harmonics Enhancer: Bass and Treble (with Harmonics sweep).
• Valve Emulation with drive.
• Preset system with randomizer.
• Formats: AU and VST (32/64-bit).
• Platforms: OS X, Windows.

Price: €45. Valve Exciter is available for the introductory price of €35 until July 31st, 2014.
Video Demo on YouTube