More scope geeking

[Chris Prosser]

Hey @DonH56,

I broke out my Bitscope and actually used it in MSO mode trying to debug something I just built and I can strongly recommend against it . From my research it looks like the manufacturer has basically moved on to other things. Software (which wasn't great to begin with) hasn't been touched since 2015 and not a single blog post about the Scope part of their business since then either.

I'm fawning over the Picoscope 2206B, the 50Mhz MSO variety. It has much larger buffers and the MSO aspect. But it's definitely something I'll need to save up for and not just impulse purchase.

During my research I also came across the Link Instruments MSO 28. About 1/2 the cost of the picoscope.

Given how much I've hated the Bitscope software over the years I've had it, that will probably be the deciding factor for me. Luckily both can be used in demo mode with no hardware.

Both are only 8 bit ADC.

On the other hand, I should probably stop fantasizing about new test equipment and actually fix the problem on my board...

--chris

 

[amirm]

I have not used either but Picoscope has become the de-facto standard in PC-based scopes. As you note, you have to realize that even their highest-end units lack sufficient resolution in their ADCs to be really useful for audio. Their need to cover much more bandwidth than audio limits the bit depth.

Also, stand-alone scopes have become ridiculously cheap. Being able to fiddle with knobs is a real asset compared to using mouse and clicking. So be sure to consider them. Some of the lower end like Rigol 1054Z ones go as little as $350 which is an incredible bargain.

 

[Chris Prosser]

Yeah, I just started unraveling the thread of standalone DSO's. Wow, that's quite a price drop from the first one I used back in 1994.

The only reason I'm leaning towards the PC based scopes is because of ergonomics. My neck isn't in great shape and bending over to use a scope makes things worse.

Now I just need to decide which hobby to sate first: my audio amplifier building, or odd electronic art things...

 

[DonH56]

Just tell yourself you are getting the DSO to facilitate both audio amplifier characterization and as a piece of dynamic electronic art...

I have used several PC-based DSOs through the years but the only one I remember is the Pico Technology PicoScope. One was a specialized high-speed, high-resolution beast that I wish I could remember but it was also very expensive. There were several other "value" PC-based units but performance and FW/SW was absolutely horrible on most of them. I cannot remember names as it has been 10+ years now (so they probably all changed anyway). Don't recall Link Instruments, looks nice....

As Amir knows I have been thinking about a 'scope for years, but given my lack of free time have never pulled the trigger (ahem ). I prefer stand-alone as I have not had a PC at my hobby bench in the past, but since so much depends upon it these days could go either way. I have used Matlab and Python interfaces (via VISA) to DSOs at work and had to have a PC around for that... But since I do drag the 'scope around some I still lean towards a stand-alone box. There are some very nice portable models available now.

I've gone back and forth between just getting a "cheap" <$500 DSO, or popping the $3k or so for a better model, but really do not use one enough to justify the higher price. I have a theory that buying the 'scope will force me to get serious about the hobby world again, but I have a string of other big-ticket purchases that belie that (cameras, etc.)

The Rigol DS1054Z has gotten a lot of good press, and some of the EE blog sites will provide a code to get it at a reduced rate from some vendors (lower han Amazon, anyway). They make some MSO versions that are more expensive; I don't think I really need MSO capability so have not really looked. (So as soon as I get one without it my long-dreamed Raspberry Pi project will come to life and I'll want MSO, natch.) Siglent is another competitor in the low-cost DSO market but their reviews have been mixed. My company spends a fortune on Tek and our rep has offered to provide me a quote with a healthy discount even for a personal 'scope so I'll probably check it out anyway, but given the huge price difference I find it hard to believe it will be competitive cost-wise.

I can check out a DSO at work and bring it home, but our cheapest ones are probably in the $25k range, and the ones I normally use are in the $250k range. I'm afraid to even think about taking one home. My boss says no problem, just sign it out, but I am sure he's just figuring on mortgaging my house for the next upgrade when I blow the thing up on one of my amp projects. And MegaMillions is being quite uncooperative in choosing my favorite numbers, sooo...

 

[March Audio]

Hey @DonH56,

I broke out my Bitscope and actually used it in MSO mode trying to debug something I just built and I can strongly recommend against it . From my research it looks like the manufacturer has basically moved on to other things. Software (which wasn't great to begin with) hasn't been touched since 2015 and not a single blog post about the Scope part of their business since then either.

I'm fawning over the Picoscope 2206B, the 50Mhz MSO variety. It has much larger buffers and the MSO aspect. But it's definitely something I'll need to save up for and not just impulse purchase.

During my research I also came across the Link Instruments MSO 28. About 1/2 the cost of the picoscope.

Given how much I've hated the Bitscope software over the years I've had it, that will probably be the deciding factor for me. Luckily both can be used in demo mode with no hardware.

Both are only 8 bit ADC.

On the other hand, I should probably stop fantasizing about new test equipment and actually fix the problem on my board...

--chris

Take a look at the Keysight scopes, their basic range is way ahead of the competition IMO. Dirt cheap too.

https://www.keysight.com/en/pcx-275...eries-oscilloscopes?nid=-32110.0&cc=AU&lc=eng

https://www.keysight.com/en/pcx-x2015004/oscilloscopes?nid=-32546.0.00&cc=AU&lc=eng

If you need MSO then you will need to step up to the 2000 series

https://www.keysight.com/en/pcx-x20...eries-oscilloscopes?nid=-32542.0&cc=AU&lc=eng

The 2002 is $2800 AUD which is about $2000

https://www.keysight.com/en/pdx-x20...ital-channels?nid=-32542.1150181&cc=AU&lc=eng

 

[amirm]

My company spends a fortune on Tek and our rep has offered to provide me a quote with a healthy discount even for a personal 'scope so I'll probably check it out anyway, but given the huge price difference I find it hard to believe it will be competitive cost-wise.

I have a 500 Mhz Tek MSO and it has the worst interface of them all. Do the ones you use at work also have the stupid dual dial UI?

The Keysight is a joy to use compared to it but the one I have doesn't have much memory and stops at 150 Mz I think.

 

[amirm]

The only reason I'm leaning towards the PC based scopes is because of ergonomics. My neck isn't in great shape and bending over to use a scope makes things worse.

My Tek scope comes with a remote interface over Ethernet that completely clones the user interface. So if you want to navigate it on the PC, you can.

 

[Superdad]

As you note, you have to realize that even their highest-end units lack sufficient resolution in their ADCs to be really useful for audio. Their need to cover much more bandwidth than audio limits the bit depth.

The same holds true for most all MSOs and DSOs—not just for display-less “PC” scopes. I know of no mfr. offering a scope with even 16-bit ADCs.
That’s what your AP is for...

 

[DonH56]

Don't know why I didn't think of Keysight; probably because the one we have in our lab is out for repair. I find the Keysight UI a bit more cumbersome but probably because I am so used to Tek's. Tek also has a value line but I have not done much research on them.

The DSOs I use at work feature things like 25 - 70 GHz bandwidth with effective sampling rates to 100~150 GS/s, 50 - 100+ MS memory, and a bunch of expensive compliance packages. We have a number of smaller portable units but those are used in the other labs so I do not use them much (mainly when one of the "digital" engineers needs help running a DSO). I think all of them are 8-bit models; some use tricks to get 10-12 bits. At the speeds we operate 6 effective bits (6 ENOB) is about it; fortunately, that is plenty for most everything we do, and timing accuracy for jitter analysis into the ps/fs range is more critical than vertical resolution.

LeCroy is also still making DSOs but we don't have any in-house. I know they market their higher resolution 12-bit line. I do not know much about the lower models in any line; a few years ago, to get 12-16 bits of resolution and 1+ MS/s it was mostly if not all 'scope modules using USB to connect to a PC. Pico does offer a few models with 16-bit resolution: https://www.picotech.com/products/oscilloscope Realistically a good sound card or audio ADC will do better than most DSOs for audio analysis of the sort the Amir is doing.

For me, at home, a 'scope is more about looking for things than performing high-resolution captures and analysis (though some do a decent job). At work, for spectral analysis I use a spectrum analyzer (reaches 44 GHz but does not do audio), and for network analysis a VNA. In the past I have piddled with stuff well over 100 GHz; if you want pricey cables, go buy a few instrument-grade cables for those sorts of frequencies! Whilst I get to play with a lot of cool toys in my day job, few of them are good for audio, alas.

 

[restorer-john]

The Rigol DS1054Z has gotten a lot of good press, and some of the EE blog sites will provide a code to get it at a reduced rate from some vendors (lower han Amazon, anyway).

I have a DS1054Z on my bench. Picked it up two years ago as I wanted screen/data capture ability over USB/LAN and it's fabulous for that. For the money, it is absolutely unbelievable. Added the free codes and got all the options out to 100MHz. I also have my trusty 20MHz cro and 50MHz Trio cro which to be honest, get ten times the use of the DSO. I have another 100MHz Cro unused.

Some of the math and data calculations on DSOs have made techs lazy for sure. The FFTs are useless on the 1054Z to be honest. No external trigger on the Rigol. It has a huge screen with so much data on it, but for my eyes, the text is a bit small- I need glasses from across the bench. The fan is very noisy and results in my turning it off, whereas the Cro would be on all day.

When I want a quick result, it's analogue.

There's nothing like analogue in Cros. Everything is instant, predictable and genuinely intuitive. But taking scope shots with a digital camera of the trace on screen was primitive.

Each has it's place and I would suggest a DSO and a CRO.