substitute of ic in the given circuit

[rajaram04]

Hello sir
here is the circuit diagram with component details



Can i use some other ic in place of the labelled one ? 741 will work in place of it or any other ic please suggest cause i am unable to get the given

 

[betwixt]

??? TL071 is very common and inexpensive.

741 might work but with reduced performance.

Brian.

 

[tpetar]

TLE2071 will be good replacement.

http://www.datasheetcatalog.org/datasheet/texasinstruments/tle2071.pdf

Whats wrong with TL071 ?

 

[pjmelect]

A 741 should work here, if you use a 741 you should reduce the 68K resistors to say 4.7k.

 

[kvtal]

741 is the best option,for the next stage use lm386 for audio amplification

 

[honey 77]

Better option you can go through LM741 op amp only,it can be work in that circuit.

 

[rajaram04]

thanks to all of you sir ,
is it possible to use 810 in place of lm386 ?

 

[tpetar]

thanks to all of you sir ,
is it possible to use 810 in place of lm386 ?

What is 810 ?

Can you tell us what you trying to do, I think that is best ?

 

[kvtal]

ya of course u can use tba810 in place of lm386
but circuit may be change

 

[rajaram04]

810 is audio amplifier ic


ya ya sir sure . . i know the design for now & let me proceed on it first then we gonna move for the compactness

 

[kvtal]

for this ic u need to keep a heat sink

 

[rajaram04]

ya sir i am using 810 with a built in heat sink on both sides but now the total system is working properly too & 741 is o.k. with 810 except that its procing a strong humm hence output sound with a flanzing effect too . why it so happening ? what can we do ? . . i am operating on 9v 250mA supply here

 

[tpetar]

Obvious not good replacement. :wink:

You can do to make this circuit on right way, or if you whant to redesign it use adequate parts replacement or even redesign whole circuit, but in that case posted circuit is out of story.

 

[D.A.(Tony)Stewart]

Check your voltages and report if you cannot fix your connections.

pin 7 = 9 ~ 9.5V = Vbat=V+
pin 4 = 0V = V-
pin 3 = V+/2 ~ 4.5V
pin 2 = same as pin 3 = V+/2 ~ 4.5V
pin 6 = output = same as pin 3 ~4.5V
Check Electret polarity of mic ~ anywhere between 2 ~ 7V .. 4.5 is ideal and you can adjust 10kΩ to achieve more or less offset.

If this is not what you get , it is wired wrong, or at least one part is bad.

You can increase 10KΩ feedback for more gain... e.g. 100KΩ (20dB) 1MΩ (40dB) but bandwidth may be reduced to 10KHz or so (ballpark) depending on GBW product.. i.e. 1MHz / 100 = 10KHz BW

 

[rajaram04]

no sir i am getting diffrent results on all the pins & got mismatched values with the one u gave .
sir please first of all let me have the proper 9volts constant proper power supply please . .
the adapter i am using is labelled 9 volts 250 mA but i am measuring between the two terminals in open circuited condition it is showing 14.50 volts i just checked it out .Too i am operating 810 i.c. on the same voltage connecting parallely with the line . . please help me to maintain the proper one so as to get the the results on each pin as u defined . .thanks

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SunnySkyguy its a kind request to you - please read what i ve mentioned here & help in splving the problem .. thanks

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I ve a lm317t i.c. for now so how can i use it to maintain the proper voltages ? please explain with circuit diagrams too . thanks

 

[D.A.(Tony)Stewart]

your schematic indicates a battery, but if you use a 9V wall adapter will normally read ~40% higher but yours is 61% over.

As long as AC ripple is low, it does not matter.

Vin+ = Vin- = Vout = V+/2 = 7.2V in your case.

Report back your voltages.

 

[rajaram04]

yaa sir , okk i solved the problem of humming & all that thing & the voltage rating at pin 3 & pin 6 is same as you told but they are a liltle bit larger as we already know its due to power supply .
The main variations i did hear is rebuild the pre amp & main audio amp very closer to each other on the practice board & tried to keep the grounds very nearer to each other as it is likely to be on a short lenght same ground line & the results wondered as i gone through internet for some studies on old taperecorder etc circuits , sir thanks a lot to you , without your help i was unable since months
sir kindly explain me bandwidth here & too please explain me to control power supply viz lm317t thanks

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presently i am getting here
pin 2 - 7.70v
pin 3 - 8.85v
pin 6 - 13.35v
pin 7 - 14.05v

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sir too if i want to increase the sensativity of microphone so as to capture from a liltle long distance what ll i ve to do then ?
shall i use one more stage of pre - amp or anything else ?
please comment . . .thanks

 

[kvtal]

no if u add one more stge u will again get noise

 

[D.A.(Tony)Stewart]

If the resistor values are correct the input bias current is exceeding spec and indicated damaged IC

presently i am getting here
pin 2 - 7.70v
pin 3 - 8.85v << sets the voltage for pin 2 & 3 but shud be 7V
pin 6 - 13.35v
pin 7 - 14.05v

 

[rajaram04]

kk so how to set the voltage for pin 3 now ? please get me the right way