Synergy Diezel VH4, Pre-Amp Module for Synergy System, All-tube, Developed by Diezel - based on the Diezel VH4, 2 Channels, Tubes: 2x 12AX7, Controls per channel: Gain, Bass, Mid, Treble, Volume, Dimensions: (W x D x H): 17.8 x 14 x 3.8 cm, Weight: 454 g