switching systems

[niftydog]

Lots of cool switching/bypass systems out there, a lot of them have the whole Dr Jeckyl and Mr Hyde thing going on though.  :shock:

I'm nearing the end of my studies, and I'm in need of a final project to design and build. One idea I'm considering is to build a "routing switcher" system, specifically for guitar based audio signals and effects.

Is anyone aware of an existing system like this?  :?:

In case you're not sure, here's a quick synopsis of what a routing switcher does.

Think of a matrix with inputs in the rows and outputs in the columns. dial up row 3, column 8 and you have the input from row 3 going to the output at column 8. ie; crosspoint matrix.

Now, dial up row three, column 5. Now, assuming you don't kill off the previous patch, you have the input of row 3 going to both outputs at columns 5 and 8.

ad infinitum... almost.

So, setting up each of your effects as individual input and output device whithin the matrix, you can patch your effects in any order, series or parallel, (even routing through one effect multiple times!?!?  :twisted: ) simply by performing a software macro.

So, anyone aware of such a system in existence? I know plenty of people are probably thinking of it, or even working on it... but does it exist?!

[Mike Burgundy]

hmmm...If you want the hemn and sleeve of this, I'd say see if you can get pointers from both Bradshaw and Midas.
That said, it exists, so youre not doing anything new. My guess is it's not the point of a final project to clone something, and it's not all that hard.
Decide what you want to do - you did that
decide on functionality - you did that
explore different technologies and solutions. How can I? How does this? What needs to? What technoloygy/technique does what and why? What's my switching strategy/philosophy? How do I explain this to people?
Off the top off my head: old-style telephone operator switching boards. The ultimate simple  matrix. But, one can use MIDI control, switching by FET, MOSFET or relay, Heck, you could do everything digital and have the programming select the correct packets off of just ONE signal line.
Select and mix-match if needed, and make a first (less channels) simple prototype to verify it's working. Re-check if you're still catering for the original question., asses what you've got, go back if needed and then, build.
We're here to help (although we should not and will not give you your end thesis in a paper bag  :twisted:  )

[niftydog]

although we should not and will not give you your end thesis in a paper bag

dang! but.. but..

nah, I think I can handle it, sheesh, five years in electronics, four years studying..  if I can't swing this then there's something wrong!

My guess is it's not the point of a final project to clone something

true, but funny thing is, they'll probably still give it the go-ahead, despite that.

I have heard that the "letter of the law" states that the final project must be "a unique, patentable and marketable product". Although, they're not terribly strict on that from what I've seen. (one guy built a tube amp, another a digital delay!)

But, I do want to spend the time doing something that I will actually use... hence this idea.

I'm currently looking into some maxim ICs for audio switching, and it'll probably end up being either PIC or ATMEL controlled.

Thanks for your input, Mike!

[R.G.]

Actually I sketched out two systems like that a few years ago. One makes a crosspoint switch with manual rotary switches and allows a footswitch row to select one of the any-order set of effects, as well as manipulating the amp's internal channel switching, reverb, tremolo, etc. as part of the programs. See "A Programmable Footswitching System" at GEO, from 2000.

Later, I showed a uController version using CMOS multiplexers to implement the crosspoint switch in the ASMOP article at GEO in 2001, with a proposed user interface, even a PCB for the crosspoint based on the PIC series of controllers. Of course, the clever thing to do today is to use one of the video or AV router cross point chips and a microcontroller to interface the footswitches to the crosspoint. See the "ASMOP" series at GEO.

If the requirements are a "unique, patentable, marketable" device, I would worry. It's certainly marketable, as the several systems that do this on the market show. It's not unique or patentable, as it reduces to interfacing a microcontroller, a user interface display and a switch matrix chip. You're relying for your degree on someone on the committee not finding out about the prior art, which has been on the web in DIY form for at least four years. I would not like to pin my hopes on getting a diploma on the chance that no one would look.

On the other hand, if I could get something like that past a thesis committee, shoot, maybe I should go back and get some more wallpaper.  

[niftydog]

You're relying for your degree on someone on the committee not finding out about the prior art

It is a bit of a worry, but that quote is hearsay... and like I mentioned, previous projects have included some particularly non-unique devices! I'm still required to go through a vetting process before I begin, so in effect they approve the concept before I start designing.  Fingers and toes crossed!

On the other hand, if I could get something like that past a thesis committee, shoot, maybe I should go back and get some more wallpaper.

Hell, you should move to sunny Canberra! Not that a degree from the Canberra Institute of Technology is going to demand much acclaim!

Australian National University on the other hand might be a better place! I'm considering converting diploma to degree there next year.

I have read through the ASMOP stuff, that's kind of what inspired me actually! Thanks for the suggestions, any specific info on crosspoint chips? I'll go trolling the net later, but if you know of any already...

[niftydog]

dang... just checking out the maxim stuff, but it's kinda hard to breadboard surface mount chips.

anyone know of a source of "adapters" that I could solder SMDs to and have a DIP device to plug into a breadboard?

[Eric H]

dang... just checking out the maxim stuff, but it's kinda hard to breadboard surface mount chips.

anyone know of a source of "adapters" that I could solder SMDs to and have a DIP device to plug into a breadboard?

These look good --especially the price
http://cimarrontechnology.com/index.asp?PageAction=VIEWCATS&Category=1

-Eric

[Fernando Aguirre]

Hi,

A system like that actually exists, It is digital and it is called Switchblade.
The company that makes it is called soundsculpture. Here is a link to the product:
http://www.soundsculpture.com/products/switchblade.htm

It is VERY versatile, it is meant to control rack gear and pedals with the ability of switch between everything that is conected to it, in all the possible combinations.
A great feature is that you can save presets with the different combination, it is midi controllable and the effects are out of the chain when not used.
Sadly it is very expensive, almost twice of a what a bradshaw system cost, but the Bradshaw stuff is not that versatile.
hope it helps
Fer

[niftydog]

christ on a bike, that switchblade is what I would call "fully featured!" Very cool.

I'm not going that crazy, no midi, and no windoze interface on my project!

[niftydog]

Thanks Eric, even have an Australian distributor!  But alas, 28 pins is as high as they go! DOH!

[Athin]

Hi,
I think It's be rather impossible to route the signal through the same effect **twice** because of a feedback loop. I've been thinking of the same thing, bu then again, after you play a bit you find that there are 2,3 sets of effects you use and that you need an easy way to switch from preset 1 to 2 or 3 to 1 rather than a way of reconfiguring everything between songs. But that's just me [the guy who couldn't build it so he made up a theory why he doesnt need it  :wink: ]. Anyway - good luck on yer project.

[niftydog]

I think It's be rather impossible to route the signal through the same effect **twice** because of a feedback loop.

not impossible...  but not necessarily musical either!

[Athin]

now that I thought of it - you could do it.. say you'd put in two signals 44.1 each, and send them both, simultaneously @ 88.2... I wonder how'd a delay respond to all this :lol:  [but you understood me right, it is possible, but pointless]

[Paul Marossy]

I'm not sure if this is in the same category as what you are talking about, but maybe this will give you some ideas: http://www.thegigrig.com/
It seems to utilize some sort of matrix system from what I can tell, looking at all those DIP switches.