# dsaum

Member Since: August 14, 2011

Country: United States

• Looking at the schematic, I see R1 and C1 forming a high pass filter, followed by C3 and R5 forming a low pass filter. The general equation for RC filter corner frequencies is

3db corner freq in hz = 1/(2 * Pi * R in ohms * C in farads)

I calculate (better check my math!)

high pass = 1/(6.28 * 2.210^+3 * 4.710^-6) = 15.4 Hz

That sounds reasonable unless you want infrasound.

low pass = 1/(6.28 * 1010^+3 * 1210^-12) = 1,300,000 Hz

That sounds a little high to me for audio!

If they used C3=12 nanofarads instead of picofarads the low pass would have been 1,300 Hz, which is in the audio ballpark.

I wonder if there is a typo in the schematic, or if the circuit is incorrect? Again, better check my analysis!

No public wish lists :(

In 2003, CU student Nate Seidle blew a power supply in his dorm room and, in lieu of a way to order easy replacements, decided to start his own company. Since then, SparkFun has been committed to sustainably helping our world achieve electronics literacy from our headquarters in Boulder, Colorado.

No matter your vision, SparkFun's products and resources are designed to make the world of electronics more accessible. In addition to over 2,000 open source components and widgets, SparkFun offers curriculum, training and online tutorials designed to help demystify the wonderful world of embedded electronics. We're here to help you start something.