Roger that one; even USB (2.0) sound cards can and will pitch fits with ungodly ground noise (E-MU 0404 USB. Yes, Creative Labs, after years of getting it right, bent me, sold me their "end-of-life" crap after one-year-plus of promises; Amazoo, $185). Been there: One solution is to lift the COMPUTER ground, which EE's, myself included, would rather not; two, is put'm CLOSE and ground'm all with HEAVY braid. My 'lab' of all trades is EMI-noisy so I use both, and it works for me.
Researched it 'til i'm worth << $1/day, mainly because of the market potential. May still be a huge market there as USB 3.0 has the SAME PROBLEM (480Mb/s a problem? Imagine 5Gb/s or so...) Read Ethernet does not have said ground issues necessarily, could be Firewire either; stopped right there as I simply want to do loudspeaker T/S parameters, audio spectrum analysis, DSP galore, stuff like that.
Still looking for the audio spectrum analyzer S/W; must be the best, free is a non-issue...
AI is it, ask IBM, and life is short so somebody else please solve the above. Thank you kindly.
@Paul - thanks for that. Most of what I have heard about the Analog Discovery has been good and it's great to have it (mostly) confirmed. It's certainly good value if you can get the student price. (Doubt you would for your commercial app but hope you get a good qty discount!) Thanks for the feedback.
I've been using the Analog Discovery for two weeks now, and had been experimenting with Digilent's Waveforms software (a free download from www.digilentinc.com) for a week or two before that. Nearly everything I've tried works the way one would expect it to work. One "gotcha" is that while the AWG can produce nearly 10 Vpp waveforms, you can't get one half of that when you use 50 ohm source impedance and drive a 50 ohm load; there is an approximately 20mA current limit on the outputs. If you stay below that current level, the spectrum analyzer indicates mid-60;s or better for THD. Another "strangie" I have yet to resolve is why a 1-second 20 Hz to 20 KHz sweep commences with a linear ramp for the first millisecond or so. I just posed this second problem to Digilent's support folks two days before Christmas, when they were already on a holiday break, but I'm sure they will have an answer for me once they get back to business next year. The support team, largely based in Romania, has been really open and responsive. My company is actually considering embedding the Analog Discovery inside of one of our systems. It is really handy that both scope channels have full differential inputs. You can make the system even more versatile by isolating the Analog Discovery's ground from your PC's ground by use of a USB isolator. (Analog Devices' CN-0160 evaluation board works really well because it allows you to supply the secondary with a hefty power supply.) Too bad the world is still waiting for a high-speed USB isolator; the Analog Discovery is seriously throttled back by the presence of a full-speed isolator.
Check out the DS203 on eBay, A pocket size 4 channel 72 MHz bandwidth digital storage oscilloscope for well under $200. 2 analog and 2 digital channels and a signal generator. Open source and upgradable with up to 4 Apps, spectrum analyzer, for example. I have been using one for the last couple of years. Works great! A wrist strap of some sort would be handy to hold it sometimes, Otherwise, no complaints.
Various versions of the myRIO platform are available. The price for the student version will be $499 and includes a complete version of LabView software. This is a very good lab for many engineering subjects.
I had not heard of that logging multimeter till you posted this blog. That one will be an interesting one to watch here in the future. Also thanks for the mention of my recent blog post on the Red Pitaya. I am excited to get some more time to play with it here in the near future.