Headphone Amplifier

High Quality unit, No need for a preamplifier

Circuit Diagram:

Headphone Amplifier Circuit Diagram

Parts:
P1 = 22K
R1 = 560R
R2 = 10K
R3 = 10K
R4 = 12K
R5 = 2.2R
R6 = 2.2R
R7 = 22R-1/2W
Q1 = BC337
Q2 = BC327
Q3 = BC337
Q4 = BC327
C1 = 1µF-63V
C2 = 100µF-25V
C3 = 100µF-25V
C4 = 100µF-25V
C5 = 22pF-63V
C6 = 22µF-25V
IC1 = NE5532
J1 = RCA audio input socket

Notes:

• Can be directly connected to CD players, tuners and tape recorders.
• Tested with several headphone models of different impedance: 32, 100, 245, 300, 600 & 2000 Ohm.
• Old 8 Ohm impedance headphones can be also driven, but these obsolete devices are not recommended.
• Schematic shows left channel and power supply (common to both channels).
• Numbers in parentheses show IC1 right channel pin connections.
• A correct grounding is very important to eliminate hum and ground loops. Connect to the same point the ground sides of J1, P1, C2, C3 & C4. Then connect separately the input and output grounds to the power supply ground.

Source : www.redcircuits.com