Not too many of us are famous enough to have our name shortened to a symbol.
Ω is the symbol representing the last name of German physicist Georg Simon Ohm.
Not only did Ohm get a symbol, he also got a law. Ohm's Law is what every electrical engineering student gets drilled into their heads. One of my mentors actually had a belt buckle with Ohm's law for its decoration. In fact, I found an
online store specializing in Ohm apparel:
![Ohms law hat](https://cdn.shopify.com/s/files/1/0672/2283/1394/files/ohms_law_cap-rb0abfab619d04aeb948cad4a60257eb9_v9wfy_8byvr_324.jpg)
Just in case you really wanted to geek out.
Ohm's law is a simplified shorthand equation for figuring out all sorts of things like the value of resistors, how much current is being used, what the voltage across components is, and so on. The more complex and thorough equation for Ohm's Law looks like this:
![Screen Shot 2017-01-25 at 8.27.15 AM](https://cdn.shopify.com/s/files/1/0672/2283/1394/files/Screen-Shot-2017-01-25-at-8_27_15-AM.png)
Yeah. That's what I thought. Too many engineers with too much time on their hands.
Important to HiFi users is input impedance, expressed in - you guessed it - Ohms.
The first input impedance we'll discuss has a great affect on sound quality. That of a phono preamplifier.
Getting the Ohms right on a phono cartridge is important and we'll find out why tomorrow.