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Virtual Oscilloscope vs Digital Oscilloscope

ajawamnet

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Nice setup, @ajawamnet . I always thought I'd have a nice home bench but never seem to have the time... I can bring stuff in to work but we don't have audio test equipment. I could bring a DSO home but shudder at the thought of schlepping home a 'scope worth more than my house.

Thanks - I work from home so it's actually my office. I'm on payroll for a company but I was the first hardware guy they hired 10 years ago and they had nothing (they've since tooled up a bit) so they have me work from home. I do a lot of side gigs for DC area companies so at least it pays for itself. One of my side gigs is working with Gary Stanfill of the old Vega Wireless - one hell of an analog guy. His partner Stan is a great RF guy... I've worked on about 300 designs with those guys (mainly audio comm gear fro ICRI and civil agencies).

Yea - I was just at Pax River NAS and they have spectrum analyzers in their lab that go for a few hundred grand. Just silly what some of that costs. It is nice that companies like Rigol are making it affordable for hams and audio enthusiasts to get decent equipment.

Where do you work at?
 
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watchnerd

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Looking at used o-scopes on eBay, it looks like all the ones nearish to me and in decent condition from a major brand, are basically the same price as newish digital scopes.

In other words, $350-450 for good used analog scopes on eBay, versus same price for new digital ones.

Given that price seems to be neutral, is there a reason to prefer old analog vs new digital?

Or vice versa?
 

Cosmik

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Looking at used o-scopes on eBay, it looks like all the ones nearish to me and in decent condition from a major brand, are basically the same price as newish digital scopes.

In other words, $350-450 for good used analog scopes on eBay, versus same price for new digital ones.

Given that price seems to be neutral, is there a reason to prefer old analog vs new digital?

Or vice versa?
I still find that a USB scope is pretty much perfect - I can't see the point of keeping an old analogue one any more, except for the nice green trace...

You've reminded me that a few years ago I built my own USB scope - just for the challenge really. The thing I really wanted to try was achieving a simulated phosphor type display using Open GL. Some screenshots of the result:

1565648116679.png


1565648178482.png
 
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watchnerd

watchnerd

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I still find that a USB scope is pretty much perfect - I can't see the point of keeping an old analogue one any more, except for the nice green trace...

You've reminded me that a few years ago I built my own USB scope - just for the challenge really. The thing I really wanted to try was achieving an analogue type display, using Open GL to give a really nice, fast, trace that looked like an analogue scope. Some screenshots:

View attachment 31195

View attachment 31196

Which USB scope do you use?

The advantage I can see, for me personally, is that I want to test analog stuff. Analog tests with analog oscopes seems simpler than making everything go through ADC.
 

Cosmik

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Which USB scope do you use?

The advantage I can see, for me personally, is that I want to test analog stuff. Analog tests with analog oscopes seems simpler than making everything go through ADC.
A Picoscope - the cheapest model. Yes, analogue scopes feel more immediate and 'connected' with what you're testing I suppose.
 

BDWoody

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If you look at my workbench, I have a soundcard data acquisition system. I have a stack of AP equipment. And sitting over that... an oscilloscope. It's 30 years old, similar to this one, and gets as much use as everything else. I made an analogy earlier about a scope being like a socket wrench set for mechanics. Yes, you can own a car and not own socket wrenches. But, if you want to start playing around with valve adjustments or changing plugs, or installing accessories, or the like, you need the basic tools. A scope and multimeter are the most basic tools before trying to be anything other than a buyer of appliances.

I've been trying to figure out how to pick one...that was as good a recommendation as any. He took $100 for it. Now, it's time to learn a lot more...by no doubt confusing the hell out of myself.

Hey, as I always say...If it's worth doing, its worth overdoing!

The socket set analogy was excellent.
 
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watchnerd

watchnerd

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I've been trying to figure out how to pick one...that was as good a recommendation as any. He took $100 for it. Now, it's time to learn a lot more...by no doubt confusing the hell out of myself.

Hey, as I always say...If it's worth doing, its worth overdoing!

The socket set analogy was excellent.

What did you end up getting?
 

KSTR

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I'm an old-fashioned guy and mostly prefer analog scopes because it's much easier to judge noise, oscillations and edge rates visually. But digital has it's place too, mostly for convenience (readouts and math functions, averaging, etc) and when you have to look at non-repetitive events, especially slow events (diagnosing circuit start-up problems and such).
My go-to scope is the venerable Fluke/Philips PM3394B with gives me both, still is portable (though neither small nor exactly lightweight) and has a lot of nice features like auto setup and auto tracking, dual timebase and all.
For simple work with audio circuits I now use REW's scope function quite often. A very handy solution with the RME Adi-2 Pro FS as DAC and ADC (good to 100kHz).
 

SIY

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I've been trying to figure out how to pick one...that was as good a recommendation as any. He took $100 for it. Now, it's time to learn a lot more...by no doubt confusing the hell out of myself.

Hey, as I always say...If it's worth doing, its worth overdoing!

The socket set analogy was excellent.

I think the Tektronix oscilloscope handbook is probably still floating around the web somewhere. Good and useful reading.
 

BDWoody

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What did you end up getting?

The one on eBay SIY linked:
Kikusui
COS6100A

That looks like a lot of fun to be had for a hundred bucks...
 

amirm

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@amirm To sum up with a Rigol 1054z or a siglent sds1104x-e will I be able to potentially make the measurements like you do in your reviews ?
Well just potentially ofc. I'm a noob looking for an oscilloscope to measure hifi audio.
Sorry for the late reply. If someone has not already answered, you can NOT use those scopes to do what I do. Their ADC (analog to digital converter) is made for speed, not resolution. They are either 8 or 10 bits in depth compared to 24 bit in my analyzer. They also do not have oscillators synchronized to scope in the way my analyzer does.

You can do some crude measurements with them but it is not at all anything like what I do.
 

SIY

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Signal generation square wave tests in 20-20khz range should be okay, though, right?

Yes. For things like transformer loading adjustment, the o-scope is the right tool.
 

diegooo1972

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@amirm
Thx for the answer. I understood that and I found that your AP 555 is just an amazing tool.
I just got back to electronics after 30 years. I'm an IT tech now.
I'm studying signal theories and amplifiers at the moment. From the beginning.
I decided for a Siglent in the end and I hope in one year to learn enough to buy and play with something like Quantasylum QA401 audio analyzer.
Seems to me a very good thing for the price.
Also the picoscopes are interresting.
I'd love to build my personal amplifier and calibrate it that way.
Can I have some fun with the QA401 in that case ?
 
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