[sdiy] Starting Point?
sleepy_dog at gmx.de
sleepy_dog at gmx.de
Sun Oct 11 15:05:52 CEST 2020
I've seen some of those < 100 $ scope things that had DC offsets,
lacking coupling options, total garbage trigger implementation and
problems like that that make it not exactly a joy to use, "entry level"
or not.
Haven't looked at them for years. If you have an extensive collection as
you say you are more likely to have come across ones that are decent -
but is that a neutral view of the average implementation you are most
likely to get, or undue bias from the ones you did like and use?
I guess one could make a list of "known usable" ones, but such a list
would become obsolete very quickly as things are today with all this no
name gear and endless copy of a copy of a product, with the goal of
further reducing the cost while being able to sell the appearance of a
known product for a better margin.
Sure, a old reputable-brand analog scope can be in bad shape, totally
decalibrated I guess - maybe in that regard it's also risky to buy one
as a beginner?
Although sometimes they throw those out for (almost) nothing :) If one
who got such a thing could get some friendly EE to look at it if it's
basically OK...
I'm not even saying specifically that alising thing really affects
anyone in reality, IDK, just wanted to thrown in a bunch of possible
examples of how one could add confusion or other aspects that might
deter a beginner.
Maybe you forgot how it can be as a total beginner because it's so long
ago for you. Stepping into a field with a lot of loose ends in the mind
and trying to make some connections and make abstract principles you
just read about become intuitive.
Gear doing funny things, it seemed to me, could disrupt that process.
(sure, at some point, observing unexpected things is important to learn
beyond the clear cut introductory textbook examples - but in the very
beginning?)
So the violin thing doesn't seem like a proper analogy.
You want people to learn violin - but standing on one toe instead of
sitting on a chair.
Bending a learning curve to your disadvantage is not virtuous. The thing
that is a virtue about putting in effort to learn something is not the
spending of the effort itself, or scrubbing the floor with a toothbrush
would be the most virtuous thing ever.
AGAIN - maybe my examples of problems with toy gear weren't good... but
I'm not sure they are the only possible problems with these wild east
products whose essence seems to be fluctuating all the time.
As you say, such gear are tools for thinkig humans - already the good
ones. Maybe bad gear is ramping up the difficulty level?
That's what I was trying to get at with maybe not the best examples.
OKAY, and perhaps I also just find it hard to believe that some < 100 $
thing of that class of instruments can be decent enough.
Just a couple years ago a 500 $ scope was looked at with suspicion, and
I bought one due to lack of options ;) (and it did have some issues)
And I don't think I'm quite the oldest fella on this list here - but it
still seems just like yesterday. Ok, maybe I'm starting to get old :D
Sorry for the long and perhaps boring text.
I just really do like to sort out how my perceptions came to be as they
are and them not aligning with the basic sentiment put forth by you.
I get it I'm only a lowly hobbyist, and worse, one that has roughly a
million other hobbies and just can't frickin stick to one :D
- Steve
Roman Sowa wrote:
>
> 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
>>>>
>>>> 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:
>>>> >
>>>> >
>>>>
>>>> _______________________________________________
>>>> Synth-diy mailing list
>>>> Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
>>>> http://synth-diy.org/mailman/listinfo/synth-diy
>>>>
>>>>
>>>> _______________________________________________
>>>> Synth-diy mailing list
>>>> Synth-diy at synth-diy.org
>>>> http://synth-diy.org/mailman/listinfo/synth-diy
>>>
>>>
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at synth-diy.org
>>> http://synth-diy.org/mailman/listinfo/synth-diy
>>
>>
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at synth-diy.org
>> http://synth-diy.org/mailman/listinfo/synth-diy
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20201011/5a6cdf76/attachment.htm>
More information about the Synth-diy
mailing list