USB Spectrum Analyzer for Mac OS X

Hey guys,

I'm looking for a spectrum analyzer to add to my work bench, I work on mac and I can't justify buying a big expensive analyser by now so I'm looking into the USB scopes available now.

I want to be able to measure THD + noise + frequency response of circuits.
I'm modifying a console and I wan't to measure the specs before and after, and also how individual components change those specs.

I was getting excited by the QuantAsylum QA400 but they don't have any support for Mac so I have to look elsewhere.

There's a nice  Lindos LA100 on eBay but for £700 its out of my price range, although I can imagine it would be an investment and it would serve me for quite a some time; how does actually unit like Lindos compare with the cheaper analyzers?

I came across the BitScope which does support mac and it's for a good price, anyone have any opinions on their units? I'm not actually sure which one will suit me best as I already have a nice analog oscilloscope and I really only need an analyzer.

Are there any other considerations for an analyzer which will run on mac?

Thanks for any input!

Hubert

I've been excited about QA400 too, but the only windows support kills me, also nowdays I trust more in a open source solution than a low cost products China based company.

This bitscope looks nice (14gr, even with a laptop attached it beats the size & weight of my old Kenwood scope) , their Micro model with raspberry pi compatibility fits an idea I've thinking about, it specs 40MSps and 8-12 bits of sample depth

Also I looked at DSO Quad scope, which specs 70MSPS and 8 bit sample depth. Looks handy and useful for basic measurements, also it includes a freq. analyser, can measure LCR.

The main doubt I've got is about the sample depth. Surely I'm wrong but standard audio interfaces sample with 24 bit depth (144db), so the can go further in noise and THD measurements, or this analyzers make the AD conversion in another way so they don' t need 24 bit to handle low signals such as noisefloor?

qa400 works (on windows), but the software is clunky and the whole thing feels cheap.  For the price it's a decent unit, but I'm not sure I'd buy one again.

How does actually unit like Lindos compare with the cheaper analyzers?

Click to expand...

I haven't tried any cheaper hardware analysers (aside from the QA, do any exist?), but I've had an LA100 for years now - it sits next to a calibrated R+S UPV B1/B3. The R+S is a luxury; having a real-time FFT screen next to me is a nice thing. Below 0.002% the R+S comes into play, but above this the LA100's accuracy is on-a-par. 

I think it was Ricardo who warned me that, were I to pony up for an AP (the R+S is a similar outlay) I'd still use the LA100 more. Well, much as the R+S impresses clients, I have to say he was right. The LA100 is an invaluable tool in telling you whether something 'works'. It turns on in seconds, with no booting necessary. I can't think of many times (if any) when the R+S told me something that I couldn't extrapolate from the LA100. It has more filtering options; but this can be an impediment as much as a strength, in that you think something's fine because THD is low, but actually it has an instability you're not seeing. The crudeness of the LA100 helps you stay focussed on the 'elephant'.

If I had to live with one or other, I'd probably take the LA100  - even at a fraction of the R+S's cost.

Calibration is the key to using software such as RMAA. If you calibrate it, you'll find it 99% as good as any hardware analyser. If your desk contains transformers then you won't need below 0.002% anyway... RMAA will tell you whether something is flat and whether it has a nasty spectral component.

As to running RMAA on a Mac...sorry - can't help there.

Hope this is of use!

BTW - there's a guy ay diyaudio developing (it appears to work - he's debugging) a USB interface for the AP Sys-One. You can find Sys-1s for even less than LA100 if you search. You'll need an old laptop to run it, not sure if Mac will be supported. You'll also need to budget for some time replacing tants and the like in the Sys-1

I have a friend with a MiniSonic MS10. It's really nice. Like Justin said about the LA100 ( which I've never seen) the MS10 isn't super low noise and can't measure super low distortion. It's a little light for design work  but for testing it's all you need. It's small, battery powered, always ready to go and has a front end designed for test and measurement.

Edit: My friend(s) have the MS20. I looked at the difference and it looks well worth the £200 to me. If I had known about it before I  got my Portable One I would have gotten the MS20. Huge price difference and the MS20 is close enough for almost everything.

Lands stuff looks really good and unfortunately I just missed out on the Lindos LA100 set on eBay, it went for £850 which is a really good price considering the new unit costs almost 4k, but I just don't have to cash right now for such an expensive unit.

MS10 looks like the way to go. I wish to find one second hand to save up as much as possible. It is still quite an expensive piece of gear but I guess it will be worth it.

anyone know if Lindos gear is supported by Mac os x or would I have to get a win laptop to run the software?

Lindos are  friendly and great for support, even on old auction-bought items (as mine was! Although I did get a 'silver' upgrade). Give them a call - they're totally cool.