Awesome feedback guys, thanks!
I am decided on the AD2. Just waiting for next paycheck in 2 weeks
Quick last question about it: what is the difference between "WaveForms" and "WaveForms 2015"?
Spend the time to review the specs for input voltages, power supply capability, etc. Direct input is limited to +- 25V - clearly enough for a lot of electronics projects but probably not enough for some circuits.
You can use x10 scope probes and probably should. You would need the BNC adapter board. I don't use mine unless I am getting out of the realm of low frequency and low voltages (I tend to work at 5V or less).
Read the note in section 2 here:
https://reference.digilentinc.com/reference/instrumentation/analog-discovery-2/reference-manual?redirect=1It takes a bit of reading to digest what it says. Read is several times! Basically, the AD is grounded through the USB connection unless a USB isolator is used. There needs to be a common ground between the circuit under test and the AD. So, when I use a separate wall wart for a supply, it better be floating because I am going to create a ground at the project (usually on the - side of the wall wart) and connect one of the AD black ground wires to that point. It isn't enough to just probe the circuit with the two scope leads (differential input like orange and orange/white or blue and blue/white), you need to get a black wire in there somewhere.
The easy way to think about this is that the blue/white or orange/white scope input wires should be connected to the circuit ground as should one of the adjacent black wires. Look at the BNC adapter schematic to figure out how Digilent handles SGND - pins 25, 28 and 30.
https://reference.digilentinc.com/_media/analog_discovery_bnc_adapter_board:discoverybnc_sch.pdfIt isn't nearly as big a bother as the note implies and it is made a whole lot easier if you are using the AD power supplies but I have to believe that the BNC adapter is the right way to use the thing as a scope. Then you can use conventional scope probes and all the SGND stuff is taken care of.
If you really need differential inputs, no problem. Just make sure that the black wire connects to circuit ground.
After a few moments of thought, this all becomes much ado about nothing. But there are circuits where the voltages are out of range or the circuit ground can't be connected to earth ground. These circuits need a lot more thought.
This stuff all applies to regular scopes as well. Dave has made a video describing how to avoid blowing up a scope. It all has to do with the ground connection! That thing can be a real issue.