1.25V to 2.5V 400Hz sine wave for calibration

[spacekid71]

Hi everyone,

I need to calibrate a Mutron Flanger clone and the build instructions are saying to use a 1.25V to 2.5V 400Hz sinewave for biasing. Is this something that I can easily build myself or buy without breaking the bank?

Thanks,

Mart

[mozz]

May be a smart phone app called signal generator, don't know what output voltage though.

[garcho]

Is this something that I can easily build

Define easy. Are you ever going to use it again? Beware the timehole...

[Rob Strand]

Are you ever going to use it again?

That's the big question.

A phone or PC output is fine for a one off.  If you stuff something up you can fry the PC sound card output or phone output.   That's the advantage of a separate unit - like building a simple sine oscillator or other.

1.25V to 2.5V 400Hz sinewave

It doesn't specify if 1.25V to 2.5V is rms or peak.

What you would do with a phone or PC is get a wavefile with a high recording level then play it back.   
You can set the level using the phone or PC output level  but to set it to a specific value you need
to measure the output with a multimeter.  (A multimeter measures the rms level, even if it's not a true rms meter.)
For a sound app you don't need a wave file as such but you should use a high-ish amplitude signal then use
the volume control to knock it down.

If the 1.25V to 2.5V spec is peak you would set the level on DMM to 1.25V/1.414 = 0.88V rms to 2.5V/1.414 = 1.77V rms.

[LaloFP]

You can use your soundcard and a generator, like REW

[garcho]

^ careful with that axe, Eugene

or buy without breaking the bank?

Look for "signal generator", there are many cheap ones, and I'm sure some caveats.


It could be a good thing for a microcontroller, and between Teensy (with the audio adaptor board) and Daisy, and I'm sure others, you have some "batteries included" options. You'll probably need to finesse their output with an op amp for the right voltage but they'll get you a decent 400Hz sine wave with little effort. When you're done calibrating the phasor you can reuse the microcontroller for anything you want, unlike any other solution.

[FSFX]

You can use the free Visual Analyser software on your PC with a sound card or digital audio interface (I use a Focusrite 2i2 third generation) to generate the tones you need. If you use that setup then you also have all of the other nice features of the VA software like dual trace scope, audio spectrum analyser, distortion analyser, etc.