This is a simple 3band graphic equalizer for audio amplifiers. There are three controls for three ranges, low frequency,mid frequency,and high; or simply for Bass, Treble and Mid range.
This circuit consists of a mini amplifier made by two BC548 transistors and the input-output differential feedback network is coupled with those controls as input.
Though this unit has own amplifier unit, it doesn’t omits the need of preamplifier(if any). Only one channel is shown, if you need to use in stereo, add another clone.
Parts list:
- Q1, Q2= BC548, or BC547, or BC549 NPN transistor
- VR1,VR2,VR3= 47K linear T/C
- R1=33K
- R2=33K
- R3=22k
- R4=22K
- R5=33K
- R6=1K
- R7=100K
- R8=4.7K
- R9=470
- C1,C2,C3=0.047µF, or 472
- C4=470pF
- C5=1µF
- C6=4.7µF
- C7=47pF
- C8=100pF
Rashmi Ranjan Rout says
Hiii ,i also love electronics,but i don't find the best ckt diagram,i have one apm (ic-LA5408) & i want to make a bass & treble ckt for it.help me easly.
Arup says
Use http://circuitsdiy.com/low-cost-effective-bass-treble-circuit-using-op-amp-741
jayu says
hi sir ARUP
in my house so much bill 1500/- per month what i am do
please help me i cant understand in electricity please tell me properly
thanks reply me
Arup says
Wrong place!
shubham says
arup sir
you mentioned a website for identifying
base emitter nd collector of a transistor
i forgot that link
please tell me that link again
it was like ...........co .uk
thanks in advance
Moaz says
Do you have a video?
Arnab says
Unfortunately no, it was a very old project.
Nirmal says
Sir diagram image is not clear I can't understand so please give clear image to make it...
Thank you
Hari says
C1 is .047 or 473 and c2 and c3 .0047 or 472