LM324 wave generator/vco schematic

[ChrisP58]

So your thinking like a tremolo circuit? Something that will oscillate the signal input?

This thread is nearly 5 years old. And the original poster hasn't logged onto this board for nearly that long.

 

[Dean Savage]

Thanks I didn't notice.

 

[Dean Savage]

Yes, I stand corrected, vibrato. I didn't look at the schematic the thread posted, but just read the comments. I was searching the web for VCO designs and tripped across it.

 

[Gasboss775]

The definition of "tremolo" is a variation of the amplitude of a musical note. The variation of frequency is called "vibrato".

At last, someone else who's got this right. The amount of misunderstanding online about these definitions is incredible, particularly within the guitar fx pedal community!

 

[Gasboss775]

Another variation of the post #7 circuit. The Opamp can be quite slow like lm358 / lm741 In this circuit the Schmitt trigger is realized with a comparator, which is able to switch very quickly in comparison to an opamp. Another reason to use a real comparator instead of an opamp is that some opamps cannot be wired as comparator's due to input protection diodes.

Triangle output from the opamp. Square wave output from the output of the comparator (lm311)

The circuit also works well with the two half's of an ne5532 ( quite fast, GBW = 10Mhz )

The pin numbers are wrong!

 

[audioguru]

At last, someone else who's got this right. The amount of misunderstanding online about these definitions is incredible, particularly within the guitar fx pedal community!

Do singers do tremolo and vibrato at the same time? Or do some singers do tremolo and other singers do vibrato? An Elvis Presley copycat on TV today sang with tons of frequency modulation but other singers have only a little amplitude modulation.

 

[Gasboss775]

Do singers do tremolo and vibrato at the same time? Or do some singers do tremolo and other singers do vibrato? An Elvis Presley copycat on TV today sang with tons of frequency modulation but other singers have only a little amplitude modulation.

My guess is that with the human voice it's probably hard to completely separate the two. I have no idea if that's actually true though, but intuitively it seems like its an idea that could have merit.
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I have made a few additions to my suggested VCO circuit. Have used the other half of the '358 as an input buffer and have also added a potential divider to provide the 1/2 Vcc bias voltage.

I've also added the correct pin numbers on the IC's.