Package include
1. M7C Tube Preamplifier Bare PCB(Stereo)
2. Assembly Manual

Introduction
Circuit design is with reference to the classical Marantz 7C. It produces sweet and detail sound. Capacitors in audio grade are used for high voltage filtering and AC signal coupling. Low voltage dropout regulator LT1085 is employed in regulating power supply for tubes filament, which gives a maximum output driving current of the IC is 3A which is far enough for filament power supply. To enhance the performance of the power supply unit, the lengths of power routing path and signal paths are minimized so as to minimize the total path impedances. The placement of the components of the built-in rectifying and regulating circuits are packaged closely together and are far from the amplifier core. Also the R14 and R30 are provided for an alternate the biasing at second amplifying stage.

Features
1. Circuit design reference to Walt Jung of American Audio Amateur Magazine.
2. Three Shuguang 12AX7B.
2. Dedicated power and ground rails for tube power and tube filaments. 
4. Symmetry in layout design for both channels.
5. Power requirement: one 200V AC (100mA) and one 12.6V AC (1A)
6. PCB dimension: 110mmx200mm, thickness 2.5mm and 2oz copper, two layers.

Optional
1. Toroidal Power Transformer T30L