--- title: "Review of EMSL's XL741" description: "Learning about an LM741 is a lot of fun with EMSL's XL741 kit. See what I think about this fully functional super-sized op-amp." canonical: "https://www.baldengineer.com/review-of-emsl-xl741.html" author: "James Lewis" date: "2015-09-03T01:25:09Z" lastmod: "2015-09-07T14:22:55Z" image: "https://www.baldengineer.com/wp-content/uploads/2015/09/XL741-and-555-with-Box-760px.jpg" categories: ["reviews"] tags: ["555","emsl","lm741","op-amp","xl741"] --- # Review of EMSL's XL741 When you need to buffer the output of an R-2R ladder or an RC filtered PWM signal, an op-amp is a single chip option. Unlike a discrete NPN transistor like a 2n3904, there is a lot going on inside of an LM741—or any op amp for that matter. What if you could look inside of the op-amp? Wouldn't it be cool to see how many transistors make up these small chips? Put your electron microscope away. The [XL741](http://bit.ly/XL741) from [Evil Mad Scientist Labs](http://www.evilmadscientist.com) is perfect for the job. I built one of these super fun solder kits and compared it to a real 741. At the core, this is a soldering kit. You get an oversized PCB, all of the necessary parts, and a few mechanical pieces. For the record, I also built up the Three-Fives. That is a [giant 555 chip it](http://bit.ly/three-fives). [![XL741 and Three-Fives Side by Side](/wp-content/uploads/2015/09/XL741-and-Three-Fives-Side-by-Side-300x200.jpg)](/wp-content/uploads/2015/09/XL741-and-Three-Fives-Side-by-Side-300x200.jpg) Every electronics geek owes it to themselves to have one of these on their bench. Not only are the designs functional, but they also look so cool. [![EMSLs XL741 Silk Screen Zoom](/wp-content/uploads/2015/09/EMSLs-XL741-Silk-Screen-Zoom-297x300.jpg)](/wp-content/uploads/2015/09/EMSLs-XL741-Silk-Screen-Zoom-297x300.jpg) Clean silk-screen identify each section of [EMSL's XL741 op-amp](http://bit.ly/XL741), which I like. So if you wanted to understand how operational amplifiers work, you could easily start poking around and see how different sub-circuits operate. For my testing, I decided to build a simple voltage-follower. My intention was to buffer the output of an Arduino Pin, with the future intention of buffering the output of an RC-Filter. [![3 Op-Amps](/wp-content/uploads/2015/09/3-Op-Amps-300x214.jpg)](/wp-content/uploads/2015/09/3-Op-Amps-300x214.jpg) Then I was suddenly hit with why there is one LM741 in my electronics kit and a bunch of LM358's. ## Performance [![EMSL's XL741 Voltage Follower](/wp-content/uploads/2015/09/XL741-Voltage-Follower-Oscilloscope-300x219.png)](/wp-content/uploads/2015/09/XL741-Voltage-Follower-Oscilloscope-300x219.png) Channel 1 (Yellow) is the output of my function generator. Channel 2 (Blue) is the output of the XL741 configured as a voltage follower. [![op-amp voltage follower circuit](/wp-content/uploads/2015/09/op-amp-voltage-follower-300x185.png)](/wp-content/uploads/2015/09/op-amp-voltage-follower-300x185.png) Notice something? Yeah, it doesn't go all the way down to zero volts. So why is this 741 not going from 0 to VCC? Well, Here's a scope capture of a real LM741. [![LM741 Voltage follower Scope](/wp-content/uploads/2015/09/LM741-Voltage-follower-Scope-300x219.png)](/wp-content/uploads/2015/09/LM741-Voltage-follower-Scope-300x219.png) Yup. That's right, now I remember. LM741s suck as single-supply op-amps. For reference here is an LM358. [![LM358 Voltage Follower VCC 5V](/wp-content/uploads/2015/09/LM358-Voltage-Follower-VCC-5V-300x219.png)](/wp-content/uploads/2015/09/LM358-Voltage-Follower-VCC-5V-300x219.png) Regardless, the XL741 is performing much like the LM741. [![XL741 and LM741 Scope Traces](/wp-content/uploads/2015/09/XL741-and-LM741-Scope-Traces-1024x369.png)](/wp-content/uploads/2015/09/XL741-and-LM741-Scope-Traces-1024x369.png) ## Is the EMSL's XL741 Worth it? Discrete components crammed on a circuit board are no match for a single piece of silicon, in terms of performance. The kit is easy to build with clear instructions, labeled components, and a very highly quality printed circuit board (PCB). The finished build is nothing short of gorgeous. No question asked: 5 out of 5 LEDs. ![Review: 5 out of 5](/wp-content/uploads/2015/01/5-out-of-5.png) Buy one of these [XL741 kit](http://bit.ly/XL741) or [Three-Fives kit](http://bit.ly/three-fives) today. They are totally worth it. ## Let's Build the XL741 For [Episode 16 of AddOhms](http://www.addohms.com/ep16), I remixed a Periscope live build of my XL741. Here's what it looks like to build one: [YouTube video uha7NoUskEg](https://www.youtube.com/watch?v=uha7NoUskEg) > **Note:** Should I review something that I don't think is awesome?