Symmetrical Class A Preamplifier


A very simple but very good amplifier unit, with low distortion. A similar modification was used as a preamplifier HAFLER. The quality however of the reproduced sound in all the symmetrical amplifiers regardless of the cost of the necessary materials, transistors, capacitor and resistors.

Circuit diagram

Circuit diagram

Part List

  • R1= 100Kohm
  • R2-3= 82Kohm
  • R4-5= 22Kohm
  • R6-7= 100ohm
  • R8= 5.6Kohm
  • R9= 100Kohm
  • R10= 1Kohm
  • C1-3= 10uF MKT
  • C2= 56pF ceramic
  • C4-5= 100nF 63V
  • C6-7= 47uF 40V
  • T1-2= BC 550C
  • T3-4= BC 560C
  • T5= BC 516
  • T6= BC 517