DIYDSP !!!

[Jason Stout]

This sounds great!!!  

[mikeb]

Peter

I'd be very interested in this on two levels:

firstly, and most importantly, as a means of being able to play around and share stuff with others. The coding side of it looks not to bad at all, and being a software engineer by 'official' profession I (and many others, no doubt) would be able to dive into it without too much fear

secondly, as a grass-roots commercial enterprise (I know you may well likely preclude this, just thought I would mention it) where $$$ changes hands to purchase the hardware (DSP device in pedal or rack form with connecting PC interface for updating), but the sofware models would be free for download. I'd venture to say this would fit well within the currently commonsound structure and arrangement

Either way, I'd be willing to contribute my time to develop a PC-based block programming and design interface for people (speciifically those who don't want to or can't dabble directly in code), as well as creating something that has a 'program' library, graphical display / config of parameters, and so on, as long as this - too - was open-source. There's nothing like the possibility that someone else will see your code that will motivate you to do a good job.

Mike

[travissk]

If I remember right, Peter put this project on the back-burner for a little while, for a few reasons, most notably needing to raise some capital for the project (development boards, etc are expensive ) as well as his recent move (hope that went well!)

That said, I'd also be available to write a user interface or code editor. I'm not sure how visual the interface can get, but even something with menus or intellisense for auto-completion of the built-ins could help abstract away some of the assembly for those who just want to mess with a simpler scripting language.

[troubledtom]

very coool !!!!!!!!!!!!!!!!
   - tom :twisted:

[donald stringer]

This would pretty much answer a lot of diyer wet dreams. To be able to reproduce a sound [as much as possible anyway] that you here without spending hours chaining boxes and eqs and switching amps. But speaking for those that are computer challenged as long there was some kind paint by no.instructions available for the begginner to get at least started this would be a pretty cool and worthwhile learning curve to invest in. Both financialy and hour wise. Would this be doable on a win98 ?

[Peter Snowberg]

Hey Chumpito,

Thanks for bumping this thread. your timing is perfect because I was starting to think of this stuff again only two days ago after a long pause for financial and time reasons.

I never really stopped thinking about it, I just slowed waaaaaaaaay down.

You asked for a status report so here it is.

There are two designs, Lotus and Soma.

Lotus consists of a pair of Wavefront AL3201B SCRs, dual 24 bit A/D, dual 24 bit D/A, a mux system that allows the SCRs to be configured in several ways including using both chips as a single long delay of 1.3 seconds. You can't get the long delay without the mux, but you could get two short delays in series. The two chips provide 250 DSP instructions per sample. The input buffers and filters are pretty basic NE5532 stuff. Same for the output filters and buffers. The microcontroller is accessed via a hacked USB/Serial converter with optoisolators to keep the computer ground and any amp ground as different animals. The user interface is not 100% specified yet, but I'm leaning toward somthing simple like a two line by 16 char LCD and maybe six buttons plus a stompswitch.

The Soma is similar, but instead of the hardware mux system, a third DSP (this time a Wavefront AL3102 "1K") emulates the mux and also adds fantastic filtering capabilities with 1024 additional DSP instructions available per sample. Soma also allows for a 4 A/D + 4 D/A configuration, or stereo A/D/A + stereo optical I/O in addition to being able to increase the number of SCRs via a small expansion board that replaces two jumpers. The user interface here has a couple more buttons and a larger or better LCD and maybe an encoder wheel too. The USB host interface is the same as the Lotus. Soma will probably also have MIDI I/O capability. MIDI costs only a few of dollars in parts and some programming.

Either design could be used with a PC or laptop to develop and modify algorithms as you listen but they are designed to be primarily stand-alone. Each also contains flash ROM for algorithm storage and E2PROM for parameter settings. Once a program has been downloaded and a set of parameters for that program has been saved, these pedals become as easy to operate as a piece of Digitiech gear. Program up - program down - preset up - preset down.

The main differences are case size, connectors, more E2PROM, more Flash, and 250 DSP instuctions per sample vs. 1270 DSP instructions per sample. Oh yea, both use Atmel AVR series chips to manage the programs and parameters behind the scenes. Atmel has their design environment available for free download too. Nice chips!

Lotus fits within 1.6" x 2.5" (4cm x 6.35cm) on a double sided board with SMDs and film caps. Soma may be a little larger. It will probably make lots of sense to make the PCBs larger for digital noise reasons.

I'm still just thinking about it and don't have any money to get boards but that may change here soon. Only time will tell.

How's that?

Peter

I'd be very interested in this on two levels:

firstly, and most importantly, as a means of being able to play around and share stuff with others. The coding side of it looks not to bad at all, and being a software engineer by 'official' profession I (and many others, no doubt) would be able to dive into it without too much fear

secondly, as a grass-roots commercial enterprise (I know you may well likely preclude this, just thought I would mention it) where $$$ changes hands to purchase the hardware (DSP device in pedal or rack form with connecting PC interface for updating), but the sofware models would be free for download. I'd venture to say this would fit well within the currently commonsound structure and arrangement

Either way, I'd be willing to contribute my time to develop a PC-based block programming and design interface for people (speciifically those who don't want to or can't dabble directly in code), as well as creating something that has a 'program' library, graphical display / config of parameters, and so on, as long as this - too - was open-source. There's nothing like the possibility that someone else will see your code that will motivate you to do a good job.

Mike

:shock:  :oops:  :mrgreen:  

That's quite a compliment Mike. Thank you.


To have these produced for people via the commonsound collective would be just amazing! I think I understand it.... the designs are available for download but only for non-commercial use and the commercial use is via the collective? I guess I'm gonna have to do some reading.

It sounds really good to me.

The big trick to this project is to have a piece of code in the Atmel AVR that will read a pot, add a bias value, scale the result, and tuck it into the appropriate spot in the appropriate DSP chip as an instruction with the data value embedded in it. It's not too much of a trick really but it's more than I have time for right now.

Thinking about the hardware end only is a motivator.

I'll post some more stuff soon. I would love to talk more about this!

Take care,
-Peter

VIVA OPEN SOURCE

[cps]

I'm also very interested in this so add me to the list.

Cheers,

Chris Share

[Athin]

looks interesting. Count me in as a Linux beta-tester. The asm looks simple, so maybe I'll be able to help there too.

[JonC]

Count me in too.

Jon.

[Sic]

wow, thats a serious idea. I wish i could be of some help, but its quite a bit out of my league. Good luck everyone who takes on this adventure... keep us informed =D

[mikeb]

This is kind of a bump ....
http://www.soundart-hot.com/english/index.htm
... is the website for a DSP rack unit which can be reprogrammed for different functions (amp modeller, reverb, analog-stype monosynth, polysynth). It has programming buttons and controls, seemingly a strong developer community - just an indication of what is possible (after man years of development and some not insignificant $$$$ but still!).

Mike

[brrt]

count me in!

grt, Brrt

[Peter Snowberg]

This is kind of a bump ....
http://www.soundart-hot.com/english/index.htm
... is the website for a DSP rack unit which can be reprogrammed for different functions (amp modeller, reverb, analog-stype monosynth, polysynth). It has programming buttons and controls, seemingly a strong developer community - just an indication of what is possible (after man years of development and some not insignificant $$$$ but still!).

Mike

That's strikingly similar to a machine I designed about 8 years ago.

If I were to do the same design today, I would probably do it around the DSP56311. The Coldfire is a really good choice for a host CPU, it's just too bad thay didn't build in some better expandability and a larger display for the user interface (I had a 256x64 graphic display ).

The Lotus and Soma designs allow for lots of things that only hardware like that could do in the past, but at a fraction of the cost. The two downsides are the limitation on  delay memory (1.35 seconds standard, expandable to 4 seconds on the Soma), and the 28 bit accumulator width. For the cost, size, and power reduction this is a very good tradeoff though.

The 56K series is still my favorite DSP, but these Wavefront chips are pretty cool! Now if they would just make one with more memory and a wider accumulator.  

Take care,
-Peter

[travissk]

The Chameleon looks awesome, at least in theory. I've actually played with one a little bit - sadly it was just using some patches the owner had on there, and I was using a keyboard, but I think the synth and effects were coming out of the unit. Pretty impressive, but then again it was a while back, so I can't compare it to anything I've used since then.

The downside is that it's somewhat expensive. Not prohibitively so; the ex-demo [used] units cost something like $450, but it's just not something I think I'd use. The site says a follow-up unit is due out next year, but they say it will be targeted toward the pro market, and that means lots of money... people joke that that many people in that demographic won't even look at anything under $1000.

[RobB]

I did stumble on some new chips from Alesis-Semi that would make a nice addition to low power amps

I'm very interested in the idea of squeezing a high quality reverb into a small amp.  

An open source, multi purpose digital effects unit sounds almost too good to be true!  Very exciting stuff.  
I'll be eagerly watching this space.

[javacody]

Peter, I'd really like to contribute to this by writing a Java wrapper around your code. You might even consider doing the whole thing in Java. It's more cross platform that way. There is also a killer Java IDE that is Open Source called Eclipse that just rocks. You can also use it for C++, C#, COBOL, and PHP amongst other languages.

I would also recommend a central website/repository for sharing algorithms and code. Perhaps sourceforge?

[Hal]

i dont think using sourceforge would be nessecary, we could post about updates here...

Im in too, as long as I have the $$.  

I have some sort of programming background...not a compsci degree, but I've done some stuff.

[ncc]

Hello,
I was just looking at a similar topic recently. The info below might be
of interest to you. The POD and other Line 6 software originated from, I believe, something called amp farm and tube technology. Anyway, the people who worked on it have a patent on the idea of modeling tubes & effects with software. The patent number is 5,789,689 and you can access it on-line and read about their invention. You might need something like a tiff image viewer plug-in (like http://www.alternatiff.com/) but this is free.
Here is how to get the info:
-go to the us patent page @ http://www.uspto.gov/patft/
-click on quick search, enter 5789689 in term 1 box, click search

- the last item in the returned list is the one you want, click on it
- click on image to see the 28 pages patent description.

I found it to be interesting reading. Enjoy,
ncc

[maximee]

BUMP

how is the DIYDSP thing progressing?
i'd be also very interested.
there once was a DSP development toolkit called the "EZ Kit Lite". It was quite affordable and there where some very cool DIY approaches to it (hooking it up with a PalmV PDA to make a pretty cool synth called the "Synth of Death")..
Unfortunately like all good things it is discontinued...

[Peter Snowberg]

Maybe one day soon I will have enough money to get some boards made, until then the project is on hold.

Every week I think about the two DSP designs I arrived at. I have not forgotten them, but I am poor these days and it's almost a question of buying a car or using that money for effects building. :|