Earlier in the year I bought a DSO Shell, that popped it’s ICL7660 chip while I was calibrating it. I was pondering yesterday trying to desolder the chip and replace it, and finally trying to get the thing working. While trying to replacement chips and what not, the costs were slowly mounting, to the point where it was getting feasible to just buy another one, fully assembled this time. Searching for something else on Gumtree, I noticed that someone local is flogging an old portable Oscillscope, for not much more than I can get a DSO Shell for.
“Portable” of course meaning “it has a handle on the top”. I don’t know the weight but I doubt you’d want to haul it around a lot. You’d also need the bench space (see second photo, I’d guess it’s about 16 inches deep).
Could be a fine thing if you’re into old (ca. 1970?) test equipment. For easy functionality I suspect another DSO might suit better.
Personally I rather rarely use just a single channel on my scope. A dual channel scope I think is much more useful. Four channels is nice to have but two’s sufficient for most things.
You don’t need to pay for high bandwidth if you’re just using it for audio. The CDU130’s 15 MHz is more than enough.
Even if I technically use only one channel, the second is extremely useful if you can use it to trigger the first channel. Like when checking some complex oscillator or resonating filter, you can put a simpler version of the signal to the second channel and have the visible channel be much more stable.
I have 2 analog oscilloscopes and no dso, and i think i’d go for the digital. I got the analog scopes for cheap, one of them is from the early 1970s and works very well. The other one looks like it’s a diy kit and is not very accurate.
The little dso’s are just fine for quick measurements on your audio diy stuff. And a LOT more compact.
If you can find a manual for the calibration procedure (i’m not sure if they’re the same for all scopes) an analog scope might still be very nice to have.
They’re super cool to look at and will accept higher frequencies and input voltages than the small dso shells and also probably have higher input impedance and sensitivity.
The big advantage I find a DSO has, is that it is a memory scope (if you want to). The signal on the screen can be frozen and / or very slowly changing signals can be made visible and seen over a long time. An analog scope can only practically show real time signals, i.e. signals that are there at that point in time. Given that audio often is of low frequencies and can be quite complex as a signal it can sometimes be difficult to get a steady image on an analog (non memory) scope (it may not trigger properly). A single trigger on a DSO will give you a steady image most of the times. Furthermore, a DSO allows you to move your viewpoint quite a bit (without changing the time scale) and will make it possible to see much more of a signal than what follows the trigger signal. Modern devices are of limited size and weight and luckily are not too expensive. My DSO is way cheaper than the analog dual 20 Mhz HAMEG I bought some 45 years ago (and it is still working!).
Quite a few budget devices use 8 bit ADCs which allows for limited granularity when sampling signals. As a consequence signals often show stair case patterns. But I found that I got used to that quite quickly because for my audio use cases the shape of a signal is often more important than the absolute amplitude values.
