is it posible to replace the lm741 opamp with ne5532 or jrc4565?. is there any way to run ne5532 as a gain amp in single supply mode?
There are almost no op-amps with dual supply (having +/- and GND connection). None of those you mentioned are dual supply. Dual supply generally means how circuit (op-amp in/out) is referenced, nothing to do with op-amp itself.
is it posible to replace the lm741 opamp with ne5532 or jrc4565?. is there any way to run ne5532 as a gain amp in single supply mode?
Note that C3 is in the wrong place. It should be moved from where it is shown to between the op-amp output and the output potentiometer. The way it is shown forces a dc current through the pot of about 3 mA which could be avoided.
is it posible to replace the lm741 opamp with ne5532 or jrc4565?. is there any way to run ne5532 as a gain amp in single supply mode?
Note that C3 is in the wrong place. It should be moved from where it is shown to between the op-amp output and the output potentiometer. The way it is shown forces a dc current through the pot of about 3 mA which could be avoided.
If opamp output stage works in class-B, loading it in this way may decrease distortion.
Moving C3 will also change the filtering characteristic of the output filter. If I assume it's audio, and the output goes into a 20k Ohm load, then the corner frequency will shift a factor of 10, and that is quite significant.
With a 2k load it will be:
1/(2e3*1e-6*2*pi) = 79.5Hz
... and this is a bit high for audio. With the implied 20k it will be 8Hz and that's "plenty" for audio.
By the way, the only op amp I remember with a “ground” power pin along with negative and positive power pins is the long-obsolete uA702 that Fairchild introduced in 1964.
Its internal circuit is quite different from the 709, 301, and 741 designs that followed it.
it worked pretty well... i replaced the 741 with njm4565, it works fine... but the 2.2 ohm resistor in the output of power amp section started to get really hot, now its half burnt am i supposed to use one with bigger value. why does it get hot first of all? it is connected series with a 0.47uf film capacitor to the ground
it worked pretty well... i replaced the 741 with njm4565, it works fine... but the 2.2 ohm resistor in the output of power amp section started to get really hot, now its half burnt am i supposed to use one with bigger value. why does it get hot first of all? it is connected series with a 0.47uf film capacitor to the ground
It means something is oscillating at high frequency.
it worked pretty well... i replaced the 741 with njm4565, it works fine... but the 2.2 ohm resistor in the output of power amp section started to get really hot, now its half burnt am i supposed to use one with bigger value. why does it get hot first of all? it is connected series with a 0.47uf film capacitor to the ground
Is there a decoupling capacitor? I don't see it on schematic. I'd place a ceramic one as close to opamp's supply pins as possible.
yeah i know that but what is it?. i think its from the bluetooth module in it. but even after i turned the module of, it still getting hot. is it okay to use a 10 ohm resistor instead of 2.2ohm.
it worked pretty well... i replaced the 741 with njm4565, it works fine... but the 2.2 ohm resistor in the output of power amp section started to get really hot, now its half burnt am i supposed to use one with bigger value. why does it get hot first of all? it is connected series with a 0.47uf film capacitor to the ground
Is there a decoupling capacitor? I don't see it on schematic. I'd place a ceramic one as close to opamp's supply pins as possible.
its not in the circuit but i have already used it
yeah i know that but what is it?. i think its from the bluetooth module in it. but even after i turned the module of, it still getting hot. is it okay to use a 10 ohm resistor instead of 2.2ohm.
i had also noticed the same when using a tda 2050 amplifier in single supply mode...
yeah i know that but what is it?. i think its from the bluetooth module in it. but even after i turned the module of, it still getting hot. is it okay to use a 10 ohm resistor instead of 2.2ohm.
Resistor is not the problem. If it gets hot with no audio, it's 100% sign of your circuit oscillating at high frequency.
it worked pretty well... i replaced the 741 with njm4565, it works fine... but the 2.2 ohm resistor in the output of power amp section started to get really hot, now its half burnt am i supposed to use one with bigger value. why does it get hot first of all? it is connected series with a 0.47uf film capacitor to the ground
Inadequate decoupling, or positive feedback due to stray capacitance. Either can cause HF oscillation, simply swapping opamps without attention to the details is fraught with such dangers. Certainly wise to include a 100nF ceramic capacitor across the supply within 1cm of the NJM4565, maybe add 5 to 10pF between inverting input and output of each opamp.
High frequency oscillations passing through the power amp will fry the Zobel network resistor as you have found out. Ironically the Zobel network is to stop the power amp oscillating...
i am soo stupid i was using a jrc2068d instead of jrc4565
I noticed this when I decided to rebuilt the circuit to a copper clad... and now its not oscilating(resistor is not getting hot) but the amplifier is making a weird sond on turning on the amp. when i turn it on with a pluged in smart phone nothing happen. is ther any way to prevent that noice?
Never pass up an opportunity to replace a 741.
i have already tried running on it on 741... but the audio is destorted. but it sounds like an audio amp from old times...
GUYS AN EXTREMELY WEIRD NEWS... I have accidentaly created a radio... After replacing the circuit with jrc4565 i changed the 220k resistor in the first circuit to 56k resistor and replaced the 2k preset with 10k according to my needs and after turning it on, the zober resistor started to get little bit warm and the opamp started oscilating.
I accidently touched the input capacitor AND I COULD HEAR MY LOCAL RADIO which is tuned to around 101mhz.
I think my opamp is oscilating at 101mhz.
how to prevent this? i have never seen something like this before... can someone plz explain this?
i dont know really what happend, i forgot to take a video of it happening, sadly, the next day, it stopped doing that. So i was not able to check it. but still weird though...
Proper decoupling and proper wiring often helps. If not then additional capacitors in feedback which make frequency range more narrow.
i have already corrected it. Now everything is working fine...