I was just meandering my way around the Adafruit.com website -- as you do -- when I ran across something that made me gasp with awe and admiration (I'm just thankful I didnít squeal with delight).
This is such a cool idea -- it's a XL741 Discrete Op-Amp Kit from those little scamps at the Evil Mad Scientist Labs. As it says on the Adafruit website: "This is a faithful and functional transistor-scale replica of the µA741 op-amp integrated circuit, the classic and ubiquitous analog workhorse."
In fact, this is an implementation of the "equivalent circuit" from the original Fairchild µA741 datasheet. It comes with terminal posts and solder points so that you can actually connect to it and build up classic and functional op-amp circuits.
But wait, there's more, because I then ran across this Discrete 555 Timer Kit, which also comes from the little rapscallions at the Evil Mad Scientist Labs. In this case, we're talking about a functional transistor-scale replica of the classic NE555 timer integrated circuit, which the Adafruit website correctly describes as "One of the most classic, popular, and all-around useful chips of all time."
I am completely blown away. I think this is a wonderful idea. I only wish I'd thought of doing something like this myself. In addition to being great to play with oneself, these kits provide an absolutely brilliant tool for teaching basic principles to newcomers to electronics. Now I think I want to learn more about those little rascals at the Evil Mad Scientist Labs...
— Max Maxfield, Editor of All Things Fun & Interesting