This Silverface era Princeton Reverb is one of the best value vintage amps you can find today. The boost has been disabled, and the reverb/mix section has been reverted back to blackface specs - so you're getting the classic '64 sound, at a fraction of the price. Not to mention this amp has likely seen very little use, and is in excellent condition. The speaker has been changed, along with the bias cap, preamp electrolytics, and a couple values for the blackface mod, but the circuit is all original otherwise.