Hi,
I would like to ask for some help with choosing an oscilloscope for audio signals, spectral analysis, distortion,... Maybe something with a 50-100 Mhz bandwidth.
I have found some osciloscopes on sale here
:
http://www.tequipment.net/OWONEDU5022.html
http://www.tequipment.net/OwonHDS1022M.html
After that I read this article about the sampling artefacts of 8 bit digital osciloscopes :
http://www.picotech.com/application...e_tutorial.html
Mooly, suggested an analog osciloscope.
What kind of osciloscopes are the best, analog, analog/digital, or fully digital?
Thanks, Alexandru
I would like to ask for some help with choosing an oscilloscope for audio signals, spectral analysis, distortion,... Maybe something with a 50-100 Mhz bandwidth.
I have found some osciloscopes on sale here
:http://www.tequipment.net/OWONEDU5022.html
http://www.tequipment.net/OwonHDS1022M.html
After that I read this article about the sampling artefacts of 8 bit digital osciloscopes
:http://www.picotech.com/application...e_tutorial.html
Mooly, suggested an analog osciloscope.
What kind of osciloscopes are the best, analog, analog/digital, or fully digital?
Thanks, Alexandru
The best scopes are the analog scopes using only switches and potentiometers. Recent cheap analog scopes have menuing systems that make them a PITA to use.
I have an HP1740A and an HP1741A - the '41 is the storage version. The basic specs are 100MHz, dual-trace + trigger view. They are the best scopes I have ever seen, highly recommended if you can find either for a reasonable price.
I have an HP1740A and an HP1741A - the '41 is the storage version. The basic specs are 100MHz, dual-trace + trigger view. They are the best scopes I have ever seen, highly recommended if you can find either for a reasonable price.
Hello Alexandru,
Something like this www.farnell.com/datasheets/28792.pdf I think would be ideal for a good all rounder. Gives you an idea what to look for. Try and get at least 20Mhz (Preferably 30 Mhz minimum) bandwidth and go for one with a high accelerating voltage (CRT) as these give a good bright trace. The one in the link above is 2KV which is a bit on the low side but O.K.
Check out Hameg and Tenma for reasonable priced gear. You also need a signal generator-- a function generator would be of more use to you -- covering say 0.1 Hz to at least 1Mhz. These usually give the choice of sine/square/triangle waveform together with other features such as frequency sweeping. Some 'scopes actually have a built in function generator.
Regards Karl
Something like this www.farnell.com/datasheets/28792.pdf I think would be ideal for a good all rounder. Gives you an idea what to look for. Try and get at least 20Mhz (Preferably 30 Mhz minimum) bandwidth and go for one with a high accelerating voltage (CRT) as these give a good bright trace. The one in the link above is 2KV which is a bit on the low side but O.K.
Check out Hameg and Tenma for reasonable priced gear. You also need a signal generator-- a function generator would be of more use to you -- covering say 0.1 Hz to at least 1Mhz. These usually give the choice of sine/square/triangle waveform together with other features such as frequency sweeping. Some 'scopes actually have a built in function generator.
Regards Karl
tryalx said:Hi,
I would like to ask for some help with choosing an oscilloscope for audio signals, spectral analysis, distortion,... Maybe something with a 50-100 Mhz bandwidth.
I have found some osciloscopes on sale here
http://www.tequipment.net/OWONEDU5022.html
http://www.tequipment.net/OwonHDS1022M.html
After that I read this article about the sampling artefacts of 8 bit digital osciloscopes
http://www.picotech.com/application...e_tutorial.html
Mooly, suggested an analog osciloscope.
What kind of osciloscopes are the best, analog, analog/digital, or fully digital?
Thanks, Alexandru
I think the USB2.0 PicoScope 2203 (318$) or 2204 (450$) are very interesting. Don't be confused from the 8bit resolution of their ADC because the sampling rates are 40MS/s and 100MS/s. My DSO Hameg HM502 has also dual ADCs of 8bit / 100MS/s each. You pay the sampling rate in reality. Also they include a basic function generator and Pico offers free of cost the software which includes the FFT analyser. You can download free the software to make an evaluation of these instruments.
Fotios
Thanks for the replies!
I have found the description here: http://www.teknetelectronics.com/DataSheet/HP_AGILENT/HP__1740A_41A.pdf
I have printed the specs and I will compare them with other brands like Hameg.
Definitely a function generator would be very useful. I also like the memory zoom feature to expand the signals. Eventually record the signal to USB drive and use the memory zoom feature.
What else... FFT would be great and the possibility to see very small signals less than 1mV and up to 120V.
I am also interested in visualizing EEG (brain and body) signals and have some filtering functions within the oscilloscope, or PC scope.
I also like the idea to be able to see the signals on the PC, which means a big screen and unlimited functionality in software. Yet, having a standalone oscilloscope has its advantages. So maybe an analog oscilloscope with USB connection to the PC and the corresponding software. Finding one with 12 bit resolution probably doubles the price.
It looks like, if I want the above features I will have to spend at least $ 2500 - 3000, which is quite a bit. I guess I need to go over the specs one by one and see which oscilloscope is the most affordable.
Please let me know if any other model/brand comes to your minds.
Thank you everybody, Alexandru
I have found the description here: http://www.teknetelectronics.com/DataSheet/HP_AGILENT/HP__1740A_41A.pdf
I have printed the specs and I will compare them with other brands like Hameg.
Definitely a function generator would be very useful. I also like the memory zoom feature to expand the signals. Eventually record the signal to USB drive and use the memory zoom feature.
What else... FFT would be great and the possibility to see very small signals less than 1mV and up to 120V.
I am also interested in visualizing EEG (brain and body) signals and have some filtering functions within the oscilloscope, or PC scope.
I also like the idea to be able to see the signals on the PC, which means a big screen and unlimited functionality in software. Yet, having a standalone oscilloscope has its advantages. So maybe an analog oscilloscope with USB connection to the PC and the corresponding software. Finding one with 12 bit resolution probably doubles the price.
It looks like, if I want the above features I will have to spend at least $ 2500 - 3000, which is quite a bit. I guess I need to go over the specs one by one and see which oscilloscope is the most affordable.
Please let me know if any other model/brand comes to your minds.
Thank you everybody, Alexandru
By the way, has anybody tried these PC scopes which com in various sampling rates up to at least 250 MSPS and at fairly reasonable prices. They appear everywhere on the net, not least on ebay.
http://www.made-in-china.com/showro...gital-Storage-Oscilloscope-USB-DSO-2090-.html
(Sorry for linking to a webshop, but I could't find a neutral site describing them. I do not mean to promote this shop or any other seller. )
http://www.made-in-china.com/showro...gital-Storage-Oscilloscope-USB-DSO-2090-.html
(Sorry for linking to a webshop, but I could't find a neutral site describing them. I do not mean to promote this shop or any other seller. )
While it is nice to have a lot of bandwidth, it costs a lot of money. 20MHz is perfectly adequate for the majority of audio applications and certainly eeg.
Digital scopes, whatever their faults, have 2 features which are absent from all but the most sophisticated analog scopes. These are storage and post-processing (e.g. fft). Digital scopes can also improve their resolution for repetitive signals by multi-sampling. You can download the trace to a PC, or in the case of the Picoscope types, it's already in there.
The Picoscope USB handheld types are highly portable and will run off a laptop (on battery). The probe is part of the unit. No question about which probes to buy... The Pico ones are only proof against low voltages though. That's not necessarily an impediment to looking at higher voltages, it just has to be remembered. Even a 2MHz scope such as these will tell you quite a lot about an audio signal.
You can always trade up if you find you are restricted by the scope's capability in the future.
w
Digital scopes, whatever their faults, have 2 features which are absent from all but the most sophisticated analog scopes. These are storage and post-processing (e.g. fft). Digital scopes can also improve their resolution for repetitive signals by multi-sampling. You can download the trace to a PC, or in the case of the Picoscope types, it's already in there.
The Picoscope USB handheld types are highly portable and will run off a laptop (on battery). The probe is part of the unit. No question about which probes to buy... The Pico ones are only proof against low voltages though. That's not necessarily an impediment to looking at higher voltages, it just has to be remembered. Even a 2MHz scope such as these will tell you quite a lot about an audio signal.
You can always trade up if you find you are restricted by the scope's capability in the future.
w
john curl said:
I suppose that has become even more important with modern hight Ft output devices too. I still have a 30 year old 15 MHz scope, but I have started to look around for something better. Unfortunately most nice used scopes are on your side of the pond, which make shipping and stuff a bit more of a problem for us eureopeans.
Otherwise, since many DIYers probably, just like me, are sitting with farily slow scopes, I have been toying with the idea that maybe one could make some simple DIY sampling device (in the sense of old fashioned analog sampling scopes). It wouldn't even have to be that good if mostly using it to look for oscillations and such things, where detection is more important than exact level and waveform. I suppose it might be a bit difficult, though, to develop such a thing without already having a fast scope.
Thank you for all the information!
If I understand correctly the preferable specs would be:
An osciloscope with an analog display (> 10kV), with a bandwidth of at least 50-100 MHz and a real time sampling rate of 1Gs/s. Preferably the sensitivity of a division should be 1mV.
A bonus would be the digital processing allowing for FFT, other math functions, and a USB connection to a PC.
Also it would be desirable to have the real time (or from storage) zoom feature.
Did I forget anything important?
A slightly cheaper solution would be to use a PC scope but then we are bound to laptop/PC.
Would these specs be advanced enough?
Regards, Alexandru
If I understand correctly the preferable specs would be:
An osciloscope with an analog display (> 10kV), with a bandwidth of at least 50-100 MHz and a real time sampling rate of 1Gs/s. Preferably the sensitivity of a division should be 1mV.
A bonus would be the digital processing allowing for FFT, other math functions, and a USB connection to a PC.
Also it would be desirable to have the real time (or from storage) zoom feature.
Did I forget anything important?
A slightly cheaper solution would be to use a PC scope but then we are bound to laptop/PC.
Would these specs be advanced enough?
Regards, Alexandru
Confusing isn't it. The high voltage I mention is the internal voltage that the tube (CRT) runs on. Higher the better as it gives a brighter sharper trace. I built my first 'scope and that used only 800 volts on a 3 inch radar tube and had the rather magnificent bandwidth of 6 Mhz And you know what -- it was fine for most things, but thats a long time ago now. Bandwidth costs money, big time, and a 30 Mhz scope will show signals beyond it's maximum spec, it's just that the amplitude falls away, in just the same way as an audio amp does.
Dare I say consider both ! if you have the cash but if it's to be just one definitely analogue.
Dual trace is a must have. A dual time base is nice and let's you do this (see pic) to expand and look at in detail ANY part of the display.
Edit -- If John is reading this, I nearly posted this picture in the "Output inductor thread" as a reality check on slew rates I thought better of it though
It shows a 1Khz squarewave as reproduced by a CD player with the trace expanded to show the ringing caused by the reconstructive filtering.
And you know what -- it was fine for most things, but thats a long time ago now. Bandwidth costs money, big time, and a 30 Mhz scope will show signals beyond it's maximum spec, it's just that the amplitude falls away, in just the same way as an audio amp does. Dare I say consider both ! if you have the cash but if it's to be just one definitely analogue.
Dual trace is a must have. A dual time base is nice and let's you do this (see pic) to expand and look at in detail ANY part of the display.
Edit -- If John is reading this, I nearly posted this picture in the "Output inductor thread" as a reality check on slew rates
I thought better of it though It shows a 1Khz squarewave as reproduced by a CD player with the trace expanded to show the ringing caused by the reconstructive filtering.
Attachments
Mooly said:...had the rather magnificent bandwidth of 6 Mhz
Believe me - audio signals have not grown more bandwidth in the last 50 years.
If you buy a 100MHz scope you will pay 10x the money for features you will use less than 1% of the time, if at all. It will almost certainly be harder to drive. Like a ....Ferrari.
In some ways, this is not a good place to ask this question, as many audiophiles are crazy, and have no sense of proportion.
Buy a sensible student-level digital scope, get some experience so you can make a judgement of your own and sell it on ebay if you outgow it.
w
For an amateur diy'er I would suggest the Velleman PCS500 PC-scope
http://www.vellemanusa.com/us/enu/product/view/?id=351379
and the PCG10 function generator
http://www.vellemanusa.com/us/enu/product/view/?id=351381
They offer very interesting features (dual channel 50MHz scope bandwidth, programmable waveform, FFT analysis and bode plot), and reasonable performances for the price. I have purchased both on ebay for less than 300 USD and I am quite satisfied. I am also thinking to purchase a HPS40 portable scope.
Best regards.
Paul
http://www.vellemanusa.com/us/enu/product/view/?id=351379
and the PCG10 function generator
http://www.vellemanusa.com/us/enu/product/view/?id=351381
They offer very interesting features (dual channel 50MHz scope bandwidth, programmable waveform, FFT analysis and bode plot), and reasonable performances for the price. I have purchased both on ebay for less than 300 USD and I am quite satisfied. I am also thinking to purchase a HPS40 portable scope.
Best regards.
Paul
Oh, in the audio realm, scope probes are the one exception where spending large amounts of money on wires is concerned, instruments being more sensitive than ears.
Buy a set of probes that match the quality of your oscilloscope. Follow the manufacturers recommendation. Better is a waste of money. Worse is a waste of money.
w
Buy a set of probes that match the quality of your oscilloscope. Follow the manufacturers recommendation. Better is a waste of money. Worse is a waste of money.
w
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