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I don't need to anymore: the Sims and Calculators do that for me.

I do like Maths; I just don't like the approach of having to do re-derivations of something that has been done before - I prefer a more pragmatic and practical approach. So I'll happily pass over the re-derivations of Sedra-Smith and hone in on the various parameters that can be optimised in some way.

I want what the final equations mean, and what the results of the final equations say. It's not like I am avoiding all Maths but these software do make things a lot easier - the calcs, the measurements, the graphing, etc...

As for sims and final implementations, so far for me, the sim is an 'indicator' as it is imperfect and the one I use doesn't take into account all parameters of a physical implementation.
I get that. But to me, is not about the derivation or re-doing what has already been done before. For me is about understanding where it came from, and I am not talking about the algebra steps, but rather the physical meaning of where this or that equation came from the circuit analysis. Just knowing the formula does nothing for me.

Calculators and sims only work on numerical values, they tell you nothing about the circuit if you do not input numerical values. That is why it is important to know how to derivate the results analytically from the circuit rather than numerically. Anecdotally, during the pandemic, I gave my students circuits without any values in them, they had to tell me how the circuits worked and/or the expected voltages/currents in terms of the input voltage/current as expressions rather than numbers; many failed. I had noticed earlier that many had been cheating by simulating the circuits and just reading the voltages/currents with a probe.

As for the sims, I agree that they are not equal to the real deal, but almost. It also depends on the Sim and the circuit/part models you are using. If you use simple and rough models, you won't get accurate results. I've regularly used really high-end sims like ADS, which make use of full wave simulators using the Method of Moments (MoM), you can draw the PCB with the parts in it and it analyses the EM fields in it, and it is almost the same thing as the lab. Granted, those simulators are used for high-frequency circuits mostly and are highly specialized. But I've also experienced that when I simulate low-frequency circuits (like audio circuits), using good and accurate circuit/part models, I experimentally get 99.9% the same of what I simulated. These days, if you are designing something at low frequencies, if your simulation results are not almost the same as the real deal, you are doing it wrong.

I don't know which simulator are you using, but even the free simulators as LTSpice or TiNA are amazing. It depends of course on the models you use, if your transistor or op-amp model are just 10 lines of SPICE code, it is most likely that you won't achieve good results.

Most people who complain about simulators, in my experience, are not very experienced with simulators. The days of Bob Pease throwing away his PC from the rooftop of National Semiconductor because the thing "lied to him" are long gone. There is no commercial circuit done today that hasn't gone through countless hours of simulation.

A colleague of mine based his entire PhD on high-power high-frequency transistor modelling, he used extremely complicated models and neural networks to achieve the same behavior as the real thing. Models these days are amazing, albeit not perfect, but close.
 
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Thanks for all the good advice! Because i am older now i don't go over one night ice. For some years now i am collecting this stuff. It is hard to just collecting it and not play with it. Now is the time to release it all. This is what i collected so far. Don't mind the mess. It is always like that at my place. The plant l;ooks dead and maybe it is. But i don't give up on it after i left it outside in freezing temperatures. IMGP4725.JPGIMGP4726.JPGIMGP4727.JPGIMGP4728.JPGIMGP4729.JPGIMGP4730.JPGIMGP4731.JPGIMGP4732.JPGIMGP4733.JPGIMGP4734.JPG
 
Thanks for all the good advice! Because i am older now i don't go over one night ice. For some years now i am collecting this stuff
You have way more than you let on! And we haven't even seen all the drawers' contents.

Will be keeping an eye for how to proceed. Let us know.
 
Untill now it was only collecting stuff here and there. I had to be patient because i know if i dive into to this too soon it will fail. But now is the time i am confident enough to open up a tube radio. The cabinets are as i got them. The story is very cool. I got them from a very old man who closed his store in 2004 due to the concurrention of internet. Now at age, he decided to sell what he has left. The store was founded in 1905. He showed me pictures and newspaper articles what took us a few hours to go trough. I liked it very much. There is much more. Many many tubes and a very nice tube tester dated back at 1940. 1 year warranty from 1940. If you like we can open up more drawers of that cabinet. I did not look at it all myself because if you open up a drawer a cloud of dust is hitting my already bad lungs.
 
Looks like there are labels on each side of the drawers but they might be faded and it's more interesting to have a look inside anyway. Maybe opening them with a vacuum pump taking in the dust is worthy.
 
I get that. But to me, ...
You do you, and I'll still do it my way.

You started from not understanding why one versed in computing would rather pass over the Maths nowadays to erecting additional strawmen.

Pease's reaction in days old: irrelevant so why mention it? ADS: irrelevant to most hobbyists and DIYers.

Anyone worth his salt would not only know his tools well, but would also know the limitations thereof instead of relying on them as panacea.

The days of proving what I know are well in my past, so now I can have fun. Long posts willing to argue just for the sake of arguing is 'passé' to me too.
 
You do you, and I'll still do it my way.

You started from not understanding why one versed in computing would rather pass over the Maths nowadays to erecting additional strawmen.

Pease's reaction in days old: irrelevant so why mention it? ADS: irrelevant to most hobbyists and DIYers.

Anyone worth his salt would not only know his tools well, but would also know the limitations thereof instead of relying on them as panacea.

The days of proving what I know are well in my past, so now I can have fun. Long posts willing to argue just for the sake of arguing is 'passé' to me too.
I'm not trying to convince you of anything. I'm just saying, that just looking at the formulas and skipping where it all comes from is a recipe for ignorance. And that simulators (including LTSpice and TiNA) are very precise and available for every hobbyist and DIYer. This was meant as a complement to the advice you gave to Rattakat rather than a plea to change your ways.
 
IMHO both (TINA and solder iron) are important for education. Developing an analog circuit starts with scetching the basic idea, put it into TINA and start simulation. If it is crap, throw it away. If it works, solder the hardware and test it against the circuit voltages/currents TINA found. Sometimes a little tuning work may arise..
 
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