3 Band Equalizer Not Working

[Zohaib Ahmad]

I recently built this circuit
but It Is not working Not getting any sound after building this circuit. Idont know where i have made a mistake.
Thanks In advance

 

[MikePP]

3 pots in circuit
2 in build ?

 

[rayma]

First check all DC voltages on the op amp pins.

 

[Zohaib Ahmad]

3 pots in circuit
2 in build ?

Yes It Has 3 Pots I Have Builts Two
Pots In Zero Board Kit and 3rd One
Pot I Have Wired Separately From Kit..
Do You Know What Is Mistake In My
Circuit??

 

[Zohaib Ahmad]

First check all DC voltages on the op amp pins.

I Have Already Checked that DC Points Again And Again
But Still It Is Not Working But I Don't Know Why

 

[rayma]

What are the DC voltages exactly?

 

[Zohaib Ahmad]

Thanks For Replying
The Exact DC Voltage Is +15 -15

 

[MikePP]

On inputs and outputs


Of the op amp

 

[Zohaib Ahmad]

But How Can I Do That?

 

[Zohaib Ahmad]

On inputs and outputs


Of the op amp

Every Connection Is Perfect But No Sound Coming
From Outputs Is There Still Any Wrong Connections?

 

[MikePP]

But How Can I Do That?

Measure them !

All you’ve confirmed is the op amp has supply so far

 

[Zohaib Ahmad]

Thanks For Answering
Yes I Have Give Proper Supply To It..

 

[Zohaib Ahmad]

Measure them !

All you’ve confirmed is the op amp has supply so far

I Have Wasted My 2 Days On It But I Think I Built It With Wrong Connections

 

[MikePP]

Thanks For Answering
Yes I Have Give Proper Supply To It..

I Have Wasted My 2 Days On It But I Think I Built It With Wrong Connections

Welcome to the reality of electronics :

Now measure the operating points and come back with results

 

[MikePP]

This is just a very close variant (read copy) of this:

 

[rayma]

First:
Connect the black meter lead to ground.
Connect the red meter lead to the negative (-) input op amp pin #6.
What does the meter read?


Second:
Connect the black meter lead to ground.
Connect the red meter lead to the output op amp pin #7.
What does the meter read?

 

[mjf]

have a look at the numbers i have drawn at the opamp......

 

[rayma]

It's a 4558, dual package. The circuit appears correct.

 

[MikePP]

The similarity to the circuit in post 15 is ........ uncanny




You need to (re) go over you work meticulously , looking for inadvertant shorts (not just to ground but to other circuit areas) or breaks


and/or 'scope the signal as it travels from node to node..

 

[rayma]

Gotta be a wrong connection, flipped polarity, etc.

Just to reassure you, many circuits won't work right the first time, since
there are too many places to make a mistake. Not at all unusual.