how to calculate maths in a guitar amp schematic.

[robo-cop]

Hello.

I have a guitar amp schematic and was just curious on a theoretical question.

Every part in the schematic "obeys" into certain mathematical equation(s), right?

I mean, the whole circuit is a (complex) mathematical equation, right?

So, for instance, if I simulate the circuit into a software circuit simulation, the sim applies certain mathematical equations to get the output signal from an input signal, yes?

So, I was wondering whether there is a software out there that does such a job.

You "feed" into it a schematic and derives the maths of it.

Is there such a thing or am I tottaly on the wrong track?

Thanx.

 

[_3iMaJ]

Thats why complicated circuits are simulated (and approximated) because the mathematics that would be used to describe the system are far far too difficult to work with by hand. In the absolute BEST situation you might have a linear circuit, however in the case of guitar amplifier that is certainly not the case. Which increases the difficulty of the mathematics by several orders of magnitude.

 

[Russlk]

There are many circuit simulators around. Many of them are based on SPICE, a program developed at the University of California (Berkley) many years ago. There is another system that I am familiar with that was developed at the University of South Florida.

A free simulator that is quite good is SwitcherCad III from Linear Technology.

 

[audioguru]

Thats why complicated circuits are simulated (and approximated) because the mathematics that would be used to describe the system are far far too difficult to work with by hand.

Not true! Complicated circuits have been broken down into simple circuits and calculated by hand for many years. I've designed and built many complicated circuits and most work perfectly from the 1st time they are turned on, without ever looking at a simulator.

 

[_3iMaJ]

A few op amps sure, but not something like a guitar amplifier. Its designed in modular fashion as you describe, but as for the direct input/output relationship that is not derived in most cases.

 

[ljcox]

A few op amps sure, but not something like a guitar amplifier. Its designed in modular fashion as you describe, but as for the direct input/output relationship that is not derived in most cases.

Not true. When I was a student we did not even have calculators. We did it all with a slide rule, maths tables and aids such as spirules for S plane calculations.

 

[Optikon]

There are many circuit simulators around. Many of them are based on SPICE, a program developed at the University of California (Berkley) many years ago. There is another system that I am familiar with that was developed at the University of South Florida.

A free simulator that is quite good is SwitcherCad III from Linear Technology.

Just out of curiosity, which one(s) are not Spice based?

 

[chemelec]

Guitar Amps have been around since I was a kid in the 1950's and even before that.
Spice Didn't even Exist, Neither did Computers.

But even than I was able to Calculate the math in amplifiers.
Guitar Amps Included and also all of the special effects circuits, used in them. (such as Fuzz and Reverb)

Each Sub circuit has a Mathmatical Equation, But you can also put all these sub circuit equations together to give an Overall Equation.

 

[robo-cop]

Guitar Amps have been around since I was a kid in the 1950's and even before that.
Spice Didn't even Exist, Neither did Computers.

But even than I was able to Calculate the math in amplifiers.
Guitar Amps Included and also all of the special effects circuits, used in them. (such as Fuzz and Reverb)

Each Sub circuit has a Mathmatical Equation, But you can also put all these sub circuit equations together to give an Overall Equation.

I want to make an algorithm of a simple tube guitar amp.

A simple tube amp has-pretty much the following knobs:

Gain, Bass, Treble, Volume, Master Out.

So,in there they are a couple of tubes (preamp,amp section);

while these tubes are inside VCA sections.

Apart from the tube there might be some capacitors and "grid resistors"...But that's all.

So, my question:

Is there a software utility that can have the schematic as an input and derive the algorithm of the circuit as an output?

And if no, any references on where to find those mathematical descriptions of the subcircuits you mention?

Thank you for the help.

 

[audioguru]

Computers weren't invented when tube amps were used.
I don't think tube circuits are taught in electronics classes anymore.
I don't think a computer can read about and understand how tube amps work.

You might be lucky to find an old tube amp engineer who can teach you their tricks. Maybe you can find info on the 'net. Then you can teach a computer geek who can write you a program if you pay him a fortune. :roll:

 

[Nigel Goodwin]

Computers weren't invented when tube amps were used.

Hardly, the first electronic computer was built in England during the second world war, and used to crack German codes - afterwards it was dismantled and the components used elsewhere, UNREAL!.

I don't think tube circuits are taught in electronics classes anymore.

We only got one lesson that mentioned valves, that was in 1972, and that was only because the teacher was away, and the temporary teacher taught us about valves.

I don't think a computer can read about and understand how tube amps work.

You might be lucky to find an old tube amp engineer who can teach you their tricks. Maybe you can find info on the 'net. Then you can teach a computer geek who can write you a program if you pay him a fortune. :roll:

Some simulators already include valve simulations, I've seen mention of them in one or two places (but you know what I think about simulators anyway!).

However, I can't see why you would want to anyway?, they are really very simple devices to use.

 

[Bradley D]

I know this is an old thread, really old... but if anyone cares, I found an application on the apple website that does this kind of thing. I don't know if it will suffice but you might as well check it out, it's free at the moment. It is called Solve Elec. It was under the math and science category in the downloads section.

 

[Hero999]

Why not post a link?

Nigel,
Heck the first computers used relays not valves and were even more unreliable and bulky.

Yes I know this is an old thread but who cares?

 

[Nigel Goodwin]

Nigel,
Heck the first computers used relays not valves and were even more unreliable and bulky.

I know, I never suggested it used valves.

 

[k7elp60]

I wouldn't be surprized if some of the first computers used tubes. I remember one of the first frequency counters that I used was built with tubes. The decade counters had 4 each dual triodes, like 12AU7's and used neon bulbs to indicate the count.

 

[Bradley D]

I don't know if it will work but still a cool program. Like I said I am really new to this stuff, trying to find out if I can build my own guitar amp so my journey begins. Here's the link, good idea Hero 999, I should of thought of that before, it was late is my excuse. lol


Apple - Downloads - Math & Science - Solve Elec


P.S. I only apologized for bringing life to an old thread because some guys ream you out for it and I never understand why. Who cares right?

 

[Netspin]

Reading through this thread how can one be less upset by the divergence of conclusions than impressed by any convergence of consensus?

Asking a question doesn't make its premise true. Or, that to ask a question assures it has an answer.

Assume that "...there is a software out there that ... you 'feed' into it a schematic and [it] derives the maths [sic] of it [the schematic]."

Why presume that "...a (complex) mathematical equation..." implies that (if it exists) it has a form that is readily solvable by hand (you know, with your eraserless pencil and scientific calculator)? Or otherwise, what then does one mean by a "complex equation"?

But then for one to "...just be curious on a theoretical question." should have been the clue that the questioner doesn't know the theory. As such, he is free to the limits of HIS imagination to create the impossible.

Therefore, before anyone attempts to ask, "How does the possession of the schematics "mathmatical equation" serve you?", I suggest that the questioner do a little more study on systems theory. [Hint: Google - LaPlace Transform; Bode Plots; Network Theory; Nyquist Plots. Their creators have long since passed on. Maybe you have a better idea.]

 

[Netspin]

21,492! Wow! How high can you go before you're the only one left?

Not true! Complicated circuits have been broken down into simple circuits and calculated by hand for many years. I've designed and built many complicated circuits and most work perfectly from the 1st time they are turned on, without ever looking at a simulator.

Nothing helps others in need more than some arrogant bystander talking about himself.

 

[grim]

Hardly, the first electronic computer was built in England during the second world war, and used to crack German codes - afterwards it was dismantled and the components used elsewhere, UNREAL!

Nigel,
Heck the first computers used relays not valves and were even more unreliable and bulky.

I know, I never suggested it used valves.

good old **broken link removed**

I was on a flight back from Malta once, and two 'old people' sat next to me. ohh dear, this will be fun. anyway had a quick hello, and he asked what I had been doing over there, and I mentioned the electronics company I been to. He said I used to be 'in' electronics, working on computers. I said he should Visit Bletchley Park, it's really interesting.



he leaned over, and whispered, conspiratorly, "I was at Bletchley Park"



as for simulation software, I will check what the guys I know use next time I visit.

 

[indulis]

Not only that, but audio amp's with tube output stages are making a comeback as are LP's... dust off those turntables.