Oscilloscopes for Audio

[nevetslab]

Hey nevetslab, that's a lot of cool equipment!

Anyone in LA or San Francisco has an easy time finding great test gear and surplus parts.

I looked at the AD2 and decided against it as i do not want a computer on my work bench. Maybe if I had more space, but not now. Hearing from people who have used both PC-based test equipment versus stand-alone test gear you get a sense of the priorities of each group, and there are certain undeniable problems with the PC approach primarily with the number of boxes that must be linked together and the latency of the displayed data. Obviously, a PC can have analysis software that is far-reaching, but there is a history of lack of support for the software and the effective short useful life-time that causes.

Some of the PC-based scopes seem particularly toy-like with a very high DIY factor, where the connections to the add-on unit are on the flimsy side and the core unit is not even shielded. Fine for a uni student who is tinkering with arduino or other digital stuff, or who has access to a proper lab. I looked at these types of things over the years and computers have gotten a lot smaller and displays much thinner, so easier to accommodate on a work bench, but still too many software issues and latency. For some tests, latency is not a problem, and for low production throughput, same deal.

The weakest link in the soundcard-based scopes and analysers is the sound card itself inasmuch as its input voltage capability is very limited and not calibrated, and the 3mm TRS connnectors are not robust. Years ago, a friend of mine and I tried out the Dr.Jordan MLS but I never had much time to work with it and he never got it to work properly for what we wanted to measure. I'm sure things have improved since then, certainly sound cards have gone from 24-bit to 32-bit although there are questions as to whether the extra bits are fully useful? bandwidth is still quite limited, although there are methods of "down-sampling" high-frequencies to the bandwidth available using rather simple circuits. Again, something I've read about but not tried.

I still prefer the aesthetic of stand-alone test equipment.The DSO does what I need at the moment and just requires that I learn how to use some of its features but is otherwise a ready-to-go package.

All good points, K O'Conner.  

At present, I also don't have room on the bench for a computer.  When I do use that Velleman box with the laptop, it's on an adjacent bench.  I never did get started with LabView-based gear, or really set up a lot of the GPIB boxes, all of which are far more serious instruments & hardware.  For my daily dirt stuff, my basic gear is a GenRad pink noise generator, either thru a GenRad Tone Burst Generator/Khrone-Hite Filter or a B & K 1027 Sine-Random Pink thru a 1617 1/3 Octave filter to drive the back-line gear, powered speakers, etc...and use my ears & a Fluke 8060A to probe with.  And of course one of my basses to plug into what's getting serviced.  Most of the time, all that's powered up is the pink noise gen & the AC Mains power analyzer used with the 30A Variac.  

That AD2 device still intrigues me.  One of my clients who works below the water line with hydrophone arrays has started using that, though I choked a bit seeing the kluge of cheap clip leads everywhere, instead of something like we're used to using.  Still the results he and his colleagues were getting was commendable.  I can tollerate a USB cable connected to a computer, and the working side of where that USB cable is tethered would be like anything I've been using for years...

An articulate arm-based monitor and a pull-out keyboard drawer from below the bench top really takes care of putting the computer into the system.  I just haven't allocated that yet.  I'm more used to getting out of the bench chair to go sit at the desk to type in my notes and grab some more coffee from the pot next to the computer.