Are you assuming that a 1GS/S, 8 bit converter can only resolve 45dB of dynamic range at 100kHz???
If so, you really need to read up on delta/sigma converters, oversampling, and noise shaping.
You tell me. I just read 2 pdfs about noise in digital scopes written by Agilent. And it seems you can decrease noise by 30dB by oversampling, using bigger buffers, and averaging, but at least one of the methods will essentially remove the noise you are trying to measure so I fail to see how that will be useful.
It also seems like about 190 microvolts is the lowest noise in some good scopes. However that was at almost 300 mhz bandwidth. Not reduced.
And it appears like very good preams have about 1 microvolt of noise, if I understand the measurements correctly. A preamp with -127dBu of noise (3.46e-7 V or 0.000000346 V/ 0,35 microvolts), is not uncommon if you are building some kind of kit, I have seen schematics even better than that.
It looks like a good USB scope is more useful than stand alone one, since you have a real computer doing the calculations for you.
And if you can oversample, average and things like that in a stand alone scope you can surely do just the same with a USB scope to decrease the noise. It looks like a 16 bit scope is better for audio at least.
I think the 16 bit Picoscope looks good, it only takes 20 volts though on 1:1 and its only 5mhz. Maybe one of those special high voltage differential probes could be useful so you can measure mains voltage.
Maybe that and a good multimeter is a good start? Maybe one of those Benchmark interfaces too? Personally I would choose that over a single 500-1000mhz scope costing the same as all those things combined. It just seems more useful.
However (somewhat) good audio gear has been around for at least 50 years so I guess you can do it with only an analog crt scope, analog signal generator and an analog multimeter too if you know how to use them properly.
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I just set auto quantize on and roll my face on the keyboard to make music, it's awesome
Yeah you thought boutique mic preamps were expensive?
'Scope inputs have a preamp. They have to impart zero nada color on the signal while amplifying it by 60dB - all without any reactive loading on the test point. For digital scopes oversampling is the norm. Signal integrity is imperative on 'scopes.
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You tell me. I just read 2 pdfs about noise in digital scopes written by Agilent. And it seems you can decrease noise by 30dB by oversampling, using bigger buffers, and averaging, but at least one of the methods will essentially remove the noise you are trying to measure so I fail to see how that will be useful.
It also seems like about 190 microvolts is the lowest noise in some good scopes. However that was at almost 300 mhz bandwidth. Not reduced.
And it appears like very good preams have about 1 microvolt of noise, if I understand the measurements correctly. A preamp with -127dBu of noise (3.46e-7 V or 0.000000346 V/ 0,35 microvolts), is not uncommon if you are building some kind of kit, I have seen schematics even better than that....
Are you really concerned with the noise in the 1MHz band on your audio preamp? 10MHz? 100MHz?
It may also be worthwhile to calculate the thernal noise of a 20kHz bandwidth on a 200 or 600 ohm impedance...
Yeah I would never breadboard anything 1/3 that size. And it was a college lab project. I wouldn't let anyone NEAR that breadboard for fear of a "misplaced" wire.
They put the 'scope in XY mode and generated the voltages to display the elements of the game. Interesting.
They put the 'scope in XY mode and generated the voltages to display the elements of the game. Interesting.
Yes, is a tribute as videogames began. Tennis name, I think, near '60, on a oscilloscope, incidentally, not chance only to entertain visitors of any lab.
The only vintage (quad vintage) gear that I have it's my early'70 DIY Tennis kit for CRT screens. Controls made with Telefunken TV spare knobs & pots, into a kodak film case....yehaa I am little oldy
Was my first videogame, pure DIY, and was very inspired to me, to avoid analog electronics and take computer science degree .
I have long thought about DIY, but have wondered what tools do I need and when will I need them. I have a basic kit, cheap multimeter, soldering iron, wire strippers, screwdrivers, etc., enough to get me started with a MFOS Weird Sound Generator or something without transformers and external power supplies. However, I wonder if I am ready to move up to a DIY synth (modular, or MFOS, or a Xoxbox kit), will I need an oscilloscope?
I am not ready to purchase now, but if I see a good deal on Ebay, why not?
So, to rekindle the spirit of the original post, for DIY kits for the intermediate level (you know, for when I level up) what would be an entry level oscilloscope? (Spec wise, not necessarily brand/make/model). I am necessarily talking about inexpensive (less than $400) with a view to purchase in the next year and a half to two years.
Satisfaction of building a real synth out of a kit would be cool.
Get a used calibrated Tek scope from e-bay, shouldnt cost more than 300-400 dolars with a calibration certificate.
If you are doing this in a day to day basis, i would probably get an old analog Tek, and a newer digital one. The older ones in my opinion are just faster and serve better as a signal "window" than the new ones, but to each his own.
Talking about signal windows, if you only want to use it as a signal tracer to troubleshoot some circuits, then you dont even need a calibration certificate, i remember i bought an 80 dolar Tek 2335 scope on e-bay around 6 years ago and its still working perfectly.
Thanks for the response! I am definitely not looking for a day to day work tool, but hopefully I can use an oscilloscope as a tool to troubleshoot DIY at least once a year, and to analyze waveforms alongside synth programming more often.
I was able to get a calibrated Tek 465B for around $150 a number of years ago. A calibrated unit will run closer to $250 these days. If I were still doing FPGA design, I'd pick up a digital storage scope. However, the 465B is a workhorse and useful for basic analog troubleshooting and viewing of waveforms. Something like that would be plenty useful for the kind of things the OP is interested in.
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