Sign in to follow this  
Followers 0
Mr. Otto

Complete Newb Question about life, the universe, impedance and everything else

10 posts in this topic

This is my first post, I've been hangin' around Midibox for a while now, already started learning electronics and all but it is my first post anyway...

I think I read something about posting rules or something but I couldn't find it again, so please excuse me for some mistakes, and english mistakes too, I'm from Brazil...

First of all I'd like to thank you all for the forum, althou I always thought this is way bigger than a forum, it is a whole community working together for the future of technology spreading...

ok then, first question :

What about impedance? I know MidiBox system works, it works very well, and I know it won't burn my computer if I try to drive Ableton Live with a Midibox64.  But I tried to understand how it really works and I couldn't find more info about impedance, I mean, I know what it is, but I really don't know what to do with it...  Is it something you needed to worry about when designing the pcb's? if so how do you know your computer's impedance? Do you have to match midibox and computer's impedance? or the voltages on a midi signals so low that it really doesn't matter?

It is probably very stupid, but at the same time you could build a simple midibox without ever making yourself that same question since all the design is done, but hey, why not ask?

That's it!

Thank you guys, keep the amazing work...

Mr. Otto

Share this post


Link to post
Share on other sites

The short answer is: MIDI is a digital signal transmitted on a current loop, so you do not really have to worry about impedance. The physical layer of that interface is standardized - follow that standard and you are fine (all MIDIbox devices you can find around here are adhering to that standard!).

The long answer is far more complex, you best start looking for Electrical Impedance in Wikipedia.

Best regards, ilmenator

Share this post


Link to post
Share on other sites

Thank you for the reply !

The short answer will be a nice guideline

Share this post


Link to post
Share on other sites
bout life, the universe, impedance and everything else

fourtytwo

Share this post


Link to post
Share on other sites

How many roads must a man walk down?

fourtytwo

Share this post


Link to post
Share on other sites

fourtytwo

We're all so glad you got the reference ;)

Share this post


Link to post
Share on other sites

Apparently it was a very good topic name to get attention.

I will definitely try more of those on better questions, or hopefully, in a few months, news, photos, anyway, proof that I'm on to something, not just asking and never starting s**t...

Well, 3 weeks ago I didn't know what a resistor was, and now I have my own precious soldering iron and a weird noise gen. from musicfromouterspace.com  prototyped on a breadboard! That's fun, my folks think I'm getting crazy though. Too much solder smoke.

Anyway, I think I got what the MIDI standard means. It is supposed to have a opto-isolator on it, so that's why your midibox won't burn your computer or vice-versa...

Thanks.

Share this post


Link to post
Share on other sites

a weird noise gen. from musicfromouterspace.com

Is that the WSG? I did one of those a while back to practice soldering. Pretty fun to play around with, aren't they?

Share this post


Link to post
Share on other sites

That's the one, great first project...

Now I'm trying out some bending, it gets weirder every time.

Share this post


Link to post
Share on other sites

Another short answer for you:

As Ilmenator pointed out, MIDI is a digital standard. You do not need to worry about impedance here.

You WILL, however, need to consider impedance on any AUDIO output/input circuitry, such as when you match AUDIO SIGNALS together, or attach them to speakers/headphones.

MBSID is one example of where impedance becomes important. Thankfully, its all there in the circuit diagrams for you. No need to worry.  8)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0