Overdrive distortion progress.

Still working on my Overdrive distortion and it is not easy as i was thinking.
Here are the spec i planned for this circuit.

- Soft Clipping (on op amp feedback) and hard clipping (after opamp) selectable
- Hard clipping with Led (to add some blinking stuff)
- not adding too much noize
- true bypass with 4066
- unipolar supply using mc-09 supply
- get a multi purpose distortion PCB (modify diodes, modify gain with trimmers, etc)


You can find a lot of great distortion on the net .. but almost all are guitar distortion, meaning the input signal is not the same, in my case input signal is about 1 to 2 Vpp which i much more that a guitar signal.
This couldn't be a problem but i can't set a high gain on the op amp because the op amp will clip (due to the limited headroom using a 9V single supply) ans the op amp clipping doesn't sounds good.
The good thing about that is the limited gain is also limited noise, but limited gain is limited distortion.
Soft clipping is done by adding diodes (1n4148 for ex.)  in the feedback path of the 1st opamp.

And for the Hard clipping. i planned to use LEDs, so they will blink when distortion happen, but a Typical Vf of a Led is 2V so after the first soft clipping op amp the signal peak is not very high (due to soft clipping) and the Hard clipping effect of the Leds is not very efficient.







You can see here the a soft clippping but peak voltage is 2 volt so the hard clipping after that will not work well..

Adding the Led after for Hard Clipping we get these results  (in RED) :

 as you see, the hard clipping is not very effective. .
So the solution i was thinking is to add a second opamp and do hard clipping after this second op amp.
(also added Led with a higher Vf to stop hard clipping when gain is  low at the second op amp)


 With R4 and R8 will be potentiometers to control the amount of soft and hard clipping ..
see the results here


need to test it in a real situation, because the mc-09 signal is not a perfect sin wave (of course) and adding accent will boost the signal and add clipping on opamp.

Roland Mc-09 Service Manual

Finally i found it ... the Roland Mc-09 Service manual.

you can download it here : http://elektrotanya.com/?q=showresult&what=roland%20mc-09&kategoria=&kat2=all

SammichSid finished

Just finished, with Ashtom , his SammichSid.
If you like great chipmusic, don't forget to listen some Ashtom tracks  here : Game video Addiktz


Great kit, well documented, thanks to Jason Williams.
Worked fine just after the finishing soldering. (and firmware upload).
If you build any kit and getting prob to upload firmware via sysex message, try to use another Midi adapter, it seems that sysex firmware upload fail with some midi adapter (and it is not related only to midibox project, i've saw a lot of other DIY project getting prob to upload firmware or data via sysex).

By the way, this sammichSid box Rocks !! what a great sound .. like it ..

Still working on the Mc-09 Overdrive

I'm still working on it but not satisfied yet with the overdrive results.
If you know a good overdrive circuit, please let me know ...

BTW, the connection point I've found to insert the overdrive inside the Mc-09 are working fine ..

Arduino midi Speak and Spell code release.

Finally i released the code.
It is a very basic version but a working one. You can find schematics and code at : http://code.google.com/p/noizeinabox/

I've also a few PCB left if someone is interested, drop me a mail.

Midi Speak and Spell/Read recap

Time for a quick recap of the project.

This project was created to connect the speak and X to a midi device enabling control over midi of the speak and x.
The result id  not to be able to make it speak my own word, but more to create some bending like sounds, similar to the already existing highly liquid kit.

Why i wanted to recreate the wheel ? just because I've tried a highly liquid midi modified speak and spell and i wanted to add more midi controlled function to it, or be able to map on a midi keyboard all preferred sounds (without changing banks for ex.)
There is a second reason : because it's possible. As someone already achieved this, i should try myself and provide the infos to the DIY community.

Current project status : the autoshutdown problem as been resolved. now everything seems to be working fine,
will clean all debug crap in the code and release it ..

Quick test of ableton controling the speak and read. (noizy)

noizeinabox speak and read midi test with ableton by noizeInaBox

Arduino Speak and Sell midi interface pinout

Here is the pinout of the Arduino Speak and Sell midi interface Shield.

The code will be, as promised, provided, but i need before releasing it to solve this autoshutdown issue, which seems to be software based an not hardware.(after each midi note it should simulate a "erase button keypress to
reset the autoshutdown counter of the speak and spell)

I plan to sell few PCB or kit if someone is interested.