Monster Power AVS 2000 Automatic Voltage Stabilizer:
Servo-controlled variable voltage transformer with microprocessor controller and electronic shutdown on over/undervoltage or overcurrent.
Two unswitched, four switched-timed outputs.
Accepts 3-30V triggers for remote turn-on capability in custom installations.
Voltage range: 80-140V output voltage at 120V RMS input. Sinewave: 339.5V P-P (±1% of regulation). Operating temperature: 40-95 degrees F.
Dimensions: 17" W by 7.75" H by 13.75" D.
Weight: 68 lbs.
Check out the Manual
https://pdf.crutchfieldonline.com/ImageBank/v20030422153100/Manuals/119/119AVS2000.PDF <---- link
This unit was used in conjunction with a Power filter to serve as the AC control center of my tube system . It is also what I used with my McIntosh gear - which I use a similar pair of devices on currently.
$ SOLD!!NOTE: the unit is 68lbs HEAVY and will certainly cost me some coin to PROPERLY pack . but it can , and will be done

Condition is "good" overall ( there is a small nick + paint chip on the top rear corner- right side)


