Various diagram

Here is the simple virtual ground schema based on discrete components. This simple design comes from miniaturization guru Sijosae. Is to make a buffer from generic discrete components. The transistors can be most any complementary pair of small-signal transistors. Suitable alternatives are the PN2222A and PN2907A. The diodes are generic small-signal types. An acceptable alternative is the 1N914. This schema has better performance than a simple resistive divider virtual ground, and the parts cost is lower than for any other schema mentioned here. It is, however, the least accurate of the buffered virtual ground diagram.

 

 Parts:

R1,R2 = 4.7K
R3,R4 = 4.7R
C1,C2 = 470uF-25V
C3,C4 = 47uF-25V
D1,D2 = 1N4148
Q1 = 2SC1384
Q2 = 2SA684
B1 = Battery