With graphic equalizer we make selective cutting off or boost, of selected departments of acoustic spectrum. With this way we can adapt the musical reproduction, in the characteristics of space where we hear. This can create however also problems if go to far specifically in the gain of some area, with result the distortion. The circuit should be made in two pieces, one for each channel, the potesometer regulation it should they are Fader. With switch S1 we can by pass the circuit, leaving the musical program, to pass without alteration (FLAT). With the potesometer RV1 we regulate the gain of each channel.

ΤΕΧΝΙΚΑ ΧΑΡΑΚΤΗΡΙΣΤΙΚΑ ΠΡΟΤΥΠΟΥ - PROTYPE SPECIFICATIONS

Απόκριση συχνότητας - Frequency Response 10ΗΖ - 30 ΚΗΖ ±0.5db
Ρύθμιση κέρδους κάθε περιοχής - Adjust Gain for eatch band ±12 dB
Ρύθμιση κέρδους - Adjust Gain for eatch Channel - 9db to +14db
S/N 82db
Παραμόρφωση (FLAT) - T.H.D 0.03%
Σύνθετη αντίσταση εισόδου - Input Impedance 47ΚΩ
Σύνθετη αντίσταση εξόδου - Output  Impedance 100Ω
Τροφοδοσία - Power Supply ±15V dc / 300 mA

Part List
R1-29=100 ohms C7=220nF 100V C20=1nF 100V
R2-5-31=1Mohms C8=100nF 100V C21=560pF
R3=47Kohms C9=47nF 100V C22=270pF
R4=15Kohms C10=27nF 100V C23=150pF
R6-28=10Kohms C11=12nF 100V C25=150pF
R7....17=1Kohms C12=6.8nF 100V C26=10uF/25V
R18....27=220Kohms C13=3.3nF 100V RV1=250Kohms Lin.
C1=47uF/25V C14=68nF 100V RV2.....12=4.7Kohms Lin.
C2=47pF C15=33nF 100V IC1...3=TL074
C3=150pF C16=18nF 100V S1=2X2 SW
C4=1.5uF 100V C17=8.2nF 100V J1...3=RCA Jack
C5=820nF 100V C18=3.9nF 100V All Resitors is 1/4W 1%
C6=390nF 100V C19=2.2nF 100V