[sdiy] Starting Point?
Roman Sowa
modular at go2.pl
Sun Oct 11 11:43:58 CEST 2020
Yes, really.
Signal amplitude of interest is well covered. You don't need 500V/div in
a scope. Analog front end is adequate to the scope bandwidth which go up
to some 30MHz in those toys. Maybe missing those 1mV/div settings in
some models, but who needs that for entry level DIY? The old analog
scopes were usually 5-20MHz and bandwidth was not the weakest pont
anyway. First 100MHz analog scope I saw was big heavy and noisy Russian
machine in mid 90's.
Aliasing in digital scopes is a thing and anybody using it is aware of
that. It's mentioned everytime someone says "oscilloscope". I think a
newbie first learns about aliasing before knowing what an oscilloscope
is. It's like saying you can't work with high voltage because it can
shock you. There is no scope that prevents aliasing, no such thing as
antialias filtering in any scope, including top range of top brands,
because it's limiting and useless. Just like there's no scope with a
button "show me what's wrong with this signal". A scope is a tool for
thinking human.
A violin will not play by itself either and if you don't know how to
play, it will only make terrible noises, even if it's $1M Stradivari.
Roman
W dniu 2020-10-10 o 11:01, sleepy_dog at gmx.de pisze:
>
> > small toy scopes for below $100. And frankly they are better than
> big 50kg scopes I had in school
>
> Really? Including the analog front end, signal amplitude it can take,
> coupling options etc?
> And those old clunky analog scopes in school certainly did not fool
> you with aliasing due to improper filtering esp. when sample rate
> drops on long time base with ridiculously low k(!)points memory depth
> (like also "cheaper" *cough* Tek DSOs just a couple years ago), making
> you see things that aren't there.
> Those below 100 bucks scopes also usually have a very low sampling
> rate to start with, right?
> (don't "need" so high frequencies in synth DIY? Well, the *intended*
> frequencies that your DIY circuits *intentionally oscillate* at may
> perhaps not need that... :D)
> Sure, he can watch a video like below and then know about that one thing.
> It seems to me when entering a subject with a million questionmarks,
> adding more confusing stuff one has to be aware of might be disorienting.
>
> https://www.youtube.com/watch?v=uWADu0aKk0w
>
>
> - Steve
>
>
> Roman Sowa wrote:
>>
>> Totally agree.
>>
>> What may not seem so obvious, there's a catch - when you can afford
>> all the fancy tools you dream of, then suddenly your creativity drops
>> down the floor. With crappy tools you have to be more creative and
>> think, imagine, explore, experiment. For example soldering - you have
>> to learn how to solder anyhow, and cheap soldering iron is not
>> forgiving, so it will force you to think what you're doing and be
>> totally aware of what to do in certain situations. I have bought my
>> first temperature controlled station about 20 years after I started
>> soldering. Only because of that I could appreciate it. In case you
>> wonder, yest it's possible to succesfully solder SMD with transformer
>> soldering gun.
>>
>> The scope is essential, I think even more than multimeter, but today
>> you can buy small toy scopes for below $100. And frankly they are
>> better than big 50kg scopes I had in school. I have quite a few of
>> those toy scopes, this is my small addiction, so if you want to ask
>> about specific model, I probably have that. Don't buy "best scope you
>> can afford", or "scope planned for the future". Those times are over.
>> Now there's new scope coming every year, cheaper and better than
>> others. After 2-3 years you'll know what to look for, and it will be
>> more GAS hitting than real measurement needs.
>>
>> It is very unpopular point of view here, but I think modern digital
>> scopes are much better that vintage analog Tek.
>>
>> Roman
>>
>> W dniu 2020-10-10 o 01:49, Peter Pearson pisze:
>>> While I agree that spending $1k will definitely get you set up, we
>>> aren't all so lucky. Especially when we're spending money made
>>> mowing lawns or working minimum wage as a youngster. What I meant
>>> was that a quality iron will really make the biggest improvement.
>>> That plus an "it works fine" multimeter and a working 20MHz
>>> oscilloscope used is almost all you need (less parts but that's
>>> subjective) to do some damage. Take the price point down from $1k
>>> to something more like $200-$300 or less and that's attainable for a
>>> lot of people.
>>>
>>> Something like this:
>>>
>>> https://www.youtube.com/watch?v=HicV3Z6XLFA
>>> <https://www.youtube.com/watch?v=HicV3Z6XLFA>
>>>
>>> BUY USED!
>>>
>>> You can work up to a $10k oscilloscope or whatever once you _need_ one.
>>>
>>> On Fri, Oct 9, 2020 at 7:36 PM Benjamin Tremblay via Synth-diy
>>> <synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>> wrote:
>>>
>>> I learned this stuff as a kid through trial, error, burned
>>> fingers, and Radio Shack. I never had more than ten or so
>>> dollars on hand, so no voltmeter, no breadboard, no spools of
>>> wire. I remember building the basic 556 “Atari punk console”
>>> circuit and just thinking it made horrible noises nobody would
>>> ever want to hear.
>>> After building light-controlled oscillators for a year, I
>>> started checking out books at Colorado State University. The
>>> ancient books were the best: Musique Concrète and this book
>>> written in Spanish from the 1940s showing how a film loop
>>> generating optical pulses going into a modulator circuit could
>>> be what we call a drum machine. My mother told me about the
>>> Telharmonium in Worcester MA she read about in Yankee Magazine.
>>> I built a Theremin using an oscillator and an AM radio, and
>>> realized it would be easier to master the violin than to get a
>>> melody out of a Theremin. Then I found the 1970s books from UCLA
>>> on what we now call West Coast Synthesis. When I got to the log
>>> tables in the middle of the book I knew I couldn’t follow it; if
>>> music was math, music was not for me.
>>> It took a couple of years of futility to realize I had to try again.
>>> Paia was so inspirational, yet at the same time I felt the kits
>>> were full of design compromises that left me in the dark about
>>> best practices. (I remember testing the Gnome after my brother
>>> put it together and we both thought it was broken; but it was
>>> just the T filter doing its crappy T filter thing.)
>>> Then I was gifted a broken Paia Proteus when I was a junior in
>>> high school. Fixing that beautiful machine gave me a new
>>> appreciation for Paia.
>>>
>>> Paia turned me onto Don Lancaster and Craig Anderton (as editor
>>> of Electronic Musician).
>>> After I got my hands on the books by Bryce Ward and Barry Klein,
>>> I really wanted to do this stuff, but I had no way to earn a
>>> living, and neither the math nor the music.
>>>
>>> How long does one have to live before you just start doing what
>>> you love?
>>>
>>> Benjamin Tremblay
>>>
>>> > On Oct 9, 2020, at 6:53 PM, Benjamin Tremblay via Synth-diy
>>> <Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>> wrote:
>>> >
>>> >
>>>
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