Casio DG-10 modified into a DG-20

So if you were a rich kid in the 80's you might have had a DG-10 or DG-20 a digital guitar made by Casio.  ($350 for the DG-10...I am guessing the DG-20 was $50 to $100 more)

I was not a rich kid in the 80's and I hadn't even heard of this until I saw one on the remake of the Take On Me video by Weezer.

So I did so looking around, figured out what the device was, then tried to by one.

I lucked out and picked up a DG-10 (like in the video)  that needed a bit of work but operated just fine...for dirt cheap...

So I got it running and played with it a bit, as I dug through the documents available I learned that I had the stripped down version, but there was also a DG-20 that had line out and MIDI out. (as well as some other sound and manual percussion switches).

Well I was jealous of the MIDI output...so I popped mine open to see how hard it would be to modify mine to add MIDI support.

I noticed that in the Service manual that the main parts seemed to be identical and even the circuits were almost identical except for some minor differences and some passive components.

I took pictures of the circuit boards top and bottom and happened to find a few pictures of a DG-20's guts.

I realized that those geniuses at Casio had built both keyboards with the same chips and almost identical circuit boards except for about 3 modified traces...depending on which version you got, some traces were whole and some were cut.

The circuit boards even had the drill holes...the only thing missing was labeling and some of the pads were coated and had to be cleaned.

So based on the schematic (they did not have board photos unlike most electronics service manuals) I basically reverse engineered the circuit boards and figured out where to add passives and jumpers, and where to remove them to convert the DG-10 into the DG-20.

(luckily mine is a DG-10 so no worries)

I can say that it was actually an easy mod...time consuming for the planning and reverse engineering, but the actual mod went pretty quickly with no problems, except for missing a jumper, and 4 passives for the line out circuit.

So the total number of parts required for the mod were:

1 slide switch
1 midi port
1  1/4" mono port
8 momentary pushbutton switches 
4 ferrite bead filters
9 diodes
3 ceramic capacitors
3 electrolytic capacitors
6 resistors

So depending on what you have on hand...$10 to $20 worth of parts...you know the Casio factory got them at bulk...so I am guessing the DG-20 cost at most $5 to $10 more to build...total cost. (some more rubber switches, two more circuit boards, and a completely different sound selector in the actual DG-10)

The result is other than how the switches and outputs look, my DG-10 is a DG-20.

I am sure nobody else is dumb enough to do this mod, but I include the photos I used and modified to show the original circuit and components and the ones requited to modify the DG-10.

I will say you don't really need the line out, but I thought bypassing the amp circuits might sound better?

Anywho the following are my modifications to the board photos I did.

 Lineout mod to schematics (not complete...just showing what I missed...

In all cases the pink (salmon?) colored lines are what needs to be added or modified, the red is the existing circuit topside components (to help me trace the circuits)

Amp circuit mods to get line out

Tone control and rhythm select panel...needed to be modified to add 4 tone switches.

If someone really gets a desire to do this mod, drop me a line and I will send all my photos and documents...

Gizmo Arpeggiator etc

I recently aquired a Yamaha DX7 that needed a tiny bit of maint to bring back to working order...It cost me $1 to fix.   I got really lucky with a really nice keyboard. (the backup battery powers all the ROMS...you can replace it with a holder and coin cell battery)

So I am fiddling around with voices (or patches or specifically Sysex files).   But I am not getting enough...

Randomly I see a YouTube video about Arpeggiators...and specifically DX7 Arpeggiators.

BTW, I am not a pro musician, and I do not understand the math behind this...

So I start searching for an Arpeggiator.  I stumble upon a device that tickles my hardware hacker cockles... Gizmo.

"Gizmo is the codename for an open source MIDI utility device which targets the Arduino Uno or Mega."

Gizmo was done (as far as I can tell) as a music theory thesis.   The documentation is the thesis, so it is a bit hard to wade through...but it is all there.

It is an Arduino, with some code and a MIDI hat on top.   The code utilizes the MIDI hat switches and rheostats to control the software.

The code seems correct..but it is very challenging to wade through, so I am only going to demo the Arpeggiator function.

(I am using a Mega and the MIDI hat)

The short version is the software utilizes the midi functions of the keyboard to manipulate other keys...giving a more complex sound than would normally be generated.

So in my case (DX7), the MIDI-OUT from the keyboard goes into the MIDI-IN on the MIDI shield, and likewise the MIDI-OUT from the shield, goes to the MIDI-IN of the keyboard. (it seems to be a Yamaha thing...my MIDI USB card is wired up the same way.)

I followed the instructions...but I kept having a compiling error...I fought it for days, then realized that I had two temp files that were fouling up the process.

(wire.cpp and wire.h)

Specifically, the instructions to run the code require two edits to standard  wires files.   My solution was to search for those two files on my computer and delete the ones that weren't  the primary files.  (It will make sense when you follow the instructions).

Anyway, this is the demo...not sure why the video was suddenly so dark...but at least the audio was ok...you will notice first I do the audio without the Arpeggiator running, then with it running.

You have to play a little bit....

I don't have an XBox 360 or a PS3...but I do like to relax with a bit of Guitar Hero or RockBand.

So when I am not mooching off friends...I get a bit of practice in at home...

For those doing the math on this, you may ask how?

On the side I have had a link for Frets On Fire, an open source GH replica. Within the forums you can find links to GH type song data.

There are also a ton of different mods to the basic software...and the original is so beta, some of the mods actually fix it.

My personal favorite mod is called Alarian (2.963 is the version I am using). It takes the basic FoF software, fixes, cleans, adds more visuals AND head to head with drums or base. (no vocals, and so far only head to head). Well now there are plenty of RB type song data out there so you have plenty to choose from...BTW you don't need to install anything else, this mod includes a well worked over version of FoF.

Of course now that you can play head to head with guitar against drums...how do you play the drums. I guess you could buy a set of RB drums...but at that point it might be easier just to get the XB360 and RB to have all the toys.

I happen to have a set of Roland electronic drums...that obviously are a billion times better than the RB or GHWT drums...but how can I use them?

That was my question ever since I first played RB at a friends house (I sucketh much on RB drums).

Of course some folks solved that problem...there are some hacked ways to use your real electronic drums with the Xbox/PS3 and RB...but I will be using my Rolands with my PC playing FoF.

This first thread looked like the answer...then I read a bit more and read this thread...which linked to this forum (Lord of the Rings online?) where some folks needed to use midi devices for something in the game...Well the Roland has MIDI out...and I had a standard USB to MIDI converter (mine is listed as E-MU XMidi 1X1).

So I downloaded the MIDI2Key linked in that last forum topic and unzipped it (v 0.9.0.4 so far). No installation required, but you do need to modify the MIDI2Key.ini file in the folder (if none then rename one of the others in the folder to that).

That is really the only hard point...I took one of the example files and simply assigned a different key to each entry, ran the software, opened up Notepad on top and started hitting the drum heads. From that I could tell which entry matched which drum head...I then put letters to match the key commands already assigned in the fretsonfire.ini file...for example...

;tom2 -blue
A1=
;HH -green
AS1=e
B1=
;tom1 -yellow
C2=t

player_2_key_drum1a = K_a
player_2_key_drum2a = K_e
player_2_key_drum3a = K_t
player_2_key_drum4a = K_u

It seems more complicated than it is.

But it works perfectly.

Obviously the FoF software is not a replacement for GH or RB...but the price is right.

There are screen shots available everywhere, and videos on Youtube.

N-Joi