So I was thinking of getting an oscilloscope for the hobby (similar to the tektronic ones I used when I was studying computer electronics back in college) and came across the "new" generation of oscilloscopes.
feedback on these?
Thanks
EDIT:
feedback on these?
Thanks
EDIT:
- I am looking at the $200-$300 USD range.
- not sure what is digital audio (the frequency range) but will be use to "debug" the various DIY projects (2 channel ones). I don't think I'll be building a DAC.
Last edited:
Any price range in mind ? What would you be using the scope for, analog audio, digital audio, etc.?
Probably closer to $400 for something decent. A name brand, 2-channel, 100MHz or 200MHz digital scope. The probes may be throwaway junk at that price, but such scopes are quite usable for the most part. However, even 200MHz of scope bandwidth isn't enough for a 100MHz DAC clock pulse to look like a square wave.
Here's a popular one in that price range: https://www.amazon.com/Siglent-Technologies-SDS1202X-Oscilloscope-Channels/dp/B06XZML6RD/ref=sr_1_12?crid=39JPTYA7T3J9B&keywords=oscilloscope&qid=1664289320&qu=eyJxc2MiOiI2LjI5IiwicXNhIjoiNS43NiIsInFzcCI6IjUuMjMifQ==&sprefix=oscilloscope,aps,179&sr=8-12&ufe=app_do:amzn1.fos.ac2169a1-b668-44b9-8bd0-5ec63b24bcb5&th=1
Here's a popular one in that price range: https://www.amazon.com/Siglent-Technologies-SDS1202X-Oscilloscope-Channels/dp/B06XZML6RD/ref=sr_1_12?crid=39JPTYA7T3J9B&keywords=oscilloscope&qid=1664289320&qu=eyJxc2MiOiI2LjI5IiwicXNhIjoiNS43NiIsInFzcCI6IjUuMjMifQ==&sprefix=oscilloscope,aps,179&sr=8-12&ufe=app_do:amzn1.fos.ac2169a1-b668-44b9-8bd0-5ec63b24bcb5&th=1
Be aware of sampling rates like 1ghz.
Each sample is 1 pixel on the screen so to get a half decent wave on the screen requires up to 50 samples.
So 1GHz sampling suddenly becomes 20MHz wave.
Each sample is 1 pixel on the screen so to get a half decent wave on the screen requires up to 50 samples.
So 1GHz sampling suddenly becomes 20MHz wave.
Not necessarily. No fundamental reason why samples can't be displayed one sample per every 5 pixels. There is usually some algorithm to 'connect the dots.'
Common rule of thumb for digital scopes is to reproduce square waves with reasonable accuracy, scope bandwidth should be at least 3 to 5 times the square wave frequency.
That's true but not everyone is looking at a square wave.
Extrapolation cant work out if its sine, square, ramp, PWM etc etc.
I design USB scopes. For zoom modes I just connect the dots with a straight line.
I dont know if its sine or square with 2 points.
I think you will love having a scope. I should have bought one long before I did, but the scopes markw4 is talking about like the sigilent and the rigol I bought just did not exist at reasonable price points. The bang for the buck is incredible. It takes a bit of time to get used to sampling scopes over the old analog ones, but I think overall, better for digital work. In digital so often you'll need to catch a one time event and it is just easy with the digital ones. Analog you'll never see a one time event. I use mine more than I expected to. Everything from probing the 485 bus on the air conditioner to I2C/SPI bus probing for numerous projects to power supply to analog. I have been using a scarlett 2i2 though for any serious audio probing. The scopes with the 8 bit samples really are not very useful for detail. Really it is a fantastic time for DIY. I remember in the early 80's my lab bought a tek 1GHz sampler box that connected to a scope for display. Mind you it just sampled at 6 bits I think. Huge box. 25 thousand. The only thing I might do different if I purchased again is spend a bit more and go 4 channel instead of the 2 I bought. Occasionally I'd like another channel. Especially for SPI bus.
@nigelwright7557
Same complex waveform problem with analog scopes. Scopes are rated in terms of bandwidth (i.e. frequency response). According to Fourier all complex waves can be represented as a series of sine waves. Whatever the highest frequency sine wave present in a complex waveform is what the scope should be rated for. Doesn't matter if its analog or digital. Also, at the rated scope bandwidth the displayed amplitude of a sine wave is 3dB down, so some waveform distortion may be present on that account.
EDIT: On the issue of only 2-points, for Nyquist to hold two filters are needed, (1) an anti-alias acquisition filter, and (2) a reconstruction filter. Some scopes can do that, but not usually entry level priced scopes.
Same complex waveform problem with analog scopes. Scopes are rated in terms of bandwidth (i.e. frequency response). According to Fourier all complex waves can be represented as a series of sine waves. Whatever the highest frequency sine wave present in a complex waveform is what the scope should be rated for. Doesn't matter if its analog or digital. Also, at the rated scope bandwidth the displayed amplitude of a sine wave is 3dB down, so some waveform distortion may be present on that account.
EDIT: On the issue of only 2-points, for Nyquist to hold two filters are needed, (1) an anti-alias acquisition filter, and (2) a reconstruction filter. Some scopes can do that, but not usually entry level priced scopes.
Last edited:
For use purely as an oscilloscope, I prefer the display of the old school analog models. I find that they better show waveform details, and are easier to read in general. Although, many digital scopes these days have similar display resolution and clarity. The primary advantage of a digital scope to me is that it also functions as a digital voltmeter, and as a frequency counter. While those two metrics can be approximately judged visually using the display graticule of an analog scope, however, the direct on screen numerical readout of those metrics via a digital scope is much more convenient. The waveform storage function of a digital scope can be very useful for certain applications, such as freezing so as to analyze, digital data signals. However, I never use that with function with audio applications, except once with audio DAC development.
Last edited:
I'm an old-school analog vacuum-tube boat-anchor scope person. They can't be beat when you need very high gain to look at noise and ground problems. There were also high gain plug-ins for the larger Tek solid state units. The traces are very sharp and you can see "fuzz" on the waveform that's impossible with a digital. Today, nobody would put up with the size, maintenance and calibration of that stuff. If you like to document things, the lack of an interface can be a big turn-off, though you can always shoot the screen with a cell phone.
A decent digital scope will do far more, and can handle the low level stuff if you build a preamp for it. Where they really shine is at the lower frequencies, where it's almost painful to look at the flashing display of an old analog scope. I don't know about the latest models but don't be sucked in by having FFT included. It's mostly worthless, compared to an actual waveform analyzer. Voltmeter and frequency counter, on the other hand, are completely useful. Expect a decent computer interface for data and screen grabs.
I'd try to increase your budget. Though you can get something that "works", you'll get something far better if you spend more. I've been looking at the Rigol MSO5074 and am very tempted. Well under $1k.
A decent digital scope will do far more, and can handle the low level stuff if you build a preamp for it. Where they really shine is at the lower frequencies, where it's almost painful to look at the flashing display of an old analog scope. I don't know about the latest models but don't be sucked in by having FFT included. It's mostly worthless, compared to an actual waveform analyzer. Voltmeter and frequency counter, on the other hand, are completely useful. Expect a decent computer interface for data and screen grabs.
I'd try to increase your budget. Though you can get something that "works", you'll get something far better if you spend more. I've been looking at the Rigol MSO5074 and am very tempted. Well under $1k.
How cheap can I go for just having a backup fault finding scope? The scope will sit in its box most of the time.
Only for analogue circuits. If digital fails Id just need a I2S signal/no signal test so a DC multimeter should do I guess?
Lots of options: https://www.ebay.com/sch/i.html?_from=R40&_nkw=digital+oscilloscope&_sacat=181939&_sop=15
Any model recommendations <$200?
Only for analogue circuits. If digital fails Id just need a I2S signal/no signal test so a DC multimeter should do I guess?
Lots of options: https://www.ebay.com/sch/i.html?_from=R40&_nkw=digital+oscilloscope&_sacat=181939&_sop=15
Any model recommendations <$200?
Don't have this, but from the review this might be a good way to go for using for diy projects. You would need a laptop or PC too
pc scope review
pc scope review
I2S you could use a rpi logic level gpio to detect wave patterns.
A logic probe may work detecting an active clock but it wont show the waveform and the rpi wont show clock waveform distortion.
Problem is that faultfinding can require some bandwidth. An audio amplifier may have a transistor stage that itself can oscillate at 80MHz or higher. A DAC might have a fault with the clock which runs at 100MHz. Most cheap scopes are limited bandwidth and or only have one-channel. That's not necessarily enough for faultfinding.
For occasional use a 100MHz, 2-channel USB scope that requires a computer to work might be a way to save some money. Can be cumbersome for regular use though.
For occasional use a 100MHz, 2-channel USB scope that requires a computer to work might be a way to save some money. Can be cumbersome for regular use though.
I was in same situation as you about a year ago and I'm very happy, that I went with nowadays production. I'm totally newbie when it comes to scopes, but ease of use and capabilities (trigger by threshold with freeze for example) are very good. I went with Siglent SDS1104X-E which is 4 channel, but if you really need just 2 you can have SDS1202X-E which is like 380$.
Digital ones were a bit like marmite (sonething either like or detest).
They have a narrow window compared to analogue - 8bits resolution, sample rate and memory depth with triggering often being in or close to that window.
Often i hear analogue scope for audio, although so far a digital DSO has done me proud for audio, power, and ADC clocking.
Digital scopes that are usb or cheaper may use software for triggering whereas the rigol and siglent etc have hardware triggering (better).
I use the scope quite a bit as a multimeter.
I’ve since added bench power supplies and a signal generator, so it’s a slippery slope!
They have a narrow window compared to analogue - 8bits resolution, sample rate and memory depth with triggering often being in or close to that window.
Often i hear analogue scope for audio, although so far a digital DSO has done me proud for audio, power, and ADC clocking.
Digital scopes that are usb or cheaper may use software for triggering whereas the rigol and siglent etc have hardware triggering (better).
I use the scope quite a bit as a multimeter.
I’ve since added bench power supplies and a signal generator, so it’s a slippery slope!
Yeah I sprung for a triple output lab bench supply after getting a scope. Weirdly, it cost me more than the scope. Both came from rigol. But I get why. The scope is a shoebox that weighs very little. There is some metal in the supply. Weighs, and is much much much deeper than the scope. The supply reminds me more of test equipment I used back in my lab days 30 years ago. I'm pleased with both. It is so nice to dial in a voltage, put protection current on, and know you are getting what you set. I suspect the generator is the next slip on my slope.
I opted for the cheaper end SMPS PSUs - I have one that gives 0-60V (250mA-1.7A), 12V and 3.3/5V whilst the other gives 0-60V (150mA-1.6A). Obviously they don't limit down to 10mA but they are compact and fit on the shelf next to the DSO which gained spousal approval even if she doesn't step into the man cave!
So far I've found the SDG1032X signal generator a great move (hacked to 60MHz, like the SDS1104X-E is hacked to 200MHz). Plug in the USB to the scope and it bode plots too so worth checking the integration between the Rigol scope and the Rigol sig gen.. then comes the cost of BNC cables, terminators etc as you probably aware of!