This is my Commodore 64 mod that I've been working on for the last few months. I built this machine to be used as a synthesizer which to run 8bit adventures MSSIAH from Sweden. I installed a sid2sid board with 2 new old stock sid 6581 chips that I got from Australia.

I repainted the machine black with the key bed white. I wanted to also repaint the keys, but I could not find a way other that stickers to get the letters back on, so I kept the keys original. I added the 4 pot mod as well as switches to deactivate the pots making ports 1 and 2 still usable for game pads. Basically the four pot mod is taking the y axis and x axis from the game ports and installing it into the machine. I also added indicator lights to the switches to let me know when they are activated. The other two pots on the left hand side is the feedback distortion loop mod, with switches and indicator lights as well.

Added 1/4 inch outputs and inputs, both with volume control. I added a custom 3.5 inch lcd screen with second input available via rca on the back. The screen is a back up monitor for a vehicle, I was able to get this lcd for only $30 including shipping from China. The screen though takes 12 volts of power, so I added a second input for a 12 volt 1 amp power supply on the back. This way the mods get there power with out tapping the c64s power. I also added a dimmer switch to the led's so that I can control the voltage they receive thus dimming the lights.

As you can see from my blog, this is not my first attempt at bending my Vl-tone. The first time through was OK, but glitchy. For my top panel I used a piece of stainless steel that unfortunately conducted the current from my potentiometers dropping the pitch. Also at the time, the only wire I had was too thick and stiff to work with. So I decided to rip it all apart and start over. This is what I did.

So here are the mods. I used a little help from Casper electronics, he has a mod sheet that gives you a few patch points and three pots. I ended up only using four of the patch points and all three of his pot mods. I also added three extra pots by externally replacing the VLs internal pots. Then I tested and tested and found twelve other patch points that I liked. So that is from the left all the pots and the black RCA jacks.

As for the white RCA jacks, they function as a switch bay triggered by the switches to the right. The smart observer will notice there are nine switches in the array. One turns the bay into a multiple, the top row (on-off-on) engages the bay or sends it to the switches below. Those switches a attached to capacitors and diodes to further change the sound. The pots about the switch array are part of a home made low pass filter with frequency and resonance. Then there is a volume and reset button.

Casio Drum Machine
This is the Casio RZ-1 Plus version. The kits are acoustic, electric and Latin. The number one best feature about this Casio version is that its has four banks of sample memory giving you the ability of sampling 16 sounds.

I painted this one white, redid the text, added wood panels, and upgraded the materials used. This mod took two months and about $100 more than my previous version.

Has a 30 point RCA patch bay that short circuits three of the eprom chips for a total of around 480 possible patches (if I did my math right). You can patch with in the chips and chip to chip. To add some more fun I've tried patching my two rz-1's together to get all sorts of crazy sounds! In addition to the patch bay there are five input / output on/off switch section with toggle switches and momentary buttons. Each toggle switch also has an LED indicator.

I also added a switch to bypass the RZ-1s main timing crystals with two getlofi LTC1799 precision oscillators to allow for some great pitch control. These also have LED indicators.

I've added 10k pots on the top to easier access the samples tone control. Also, I replaced the internal permanent soldered battery with a replaceable one.

Casio Drum Machine
Has a 24 point RCA patch bay that short circuits three of the four eprom chips. The different chips are for certain samples, so some patches effect only certain sounds. You can patch with in the chips and chip to chip. In addition to the patch bay there are four input / output on/off switch section with toggle switches and momentary buttons.
There is now a switch to bypass the RZ-1s main timing crystals with two getlofi 1799 precision oscillators to allow for some great pitch control. I still have a little bit of tweaking to do with some different pots and resistors.
I've added 10k pots on the top to easier access the samples tone control. Also, I replaced the internal permanent soldered battery with a replaceable one.

This is a home made diy synthesizer built from two getlofi.com 555 timer kits. This two oscillator synth has a square wave output and a very weak triangle wave output, both waves are switch able. Osc 2 can be synced with osc 1 or ran independently. Both oscillators have a pitch control and a volume control. There is a setting which allows you to control the pitch through two photo resistors, with one of them being tilted to allow for variation.

There are four outputs on this machine, two RCA and two 1/4", one of each is for osc 1 and 2. There is a 9 volt battery inside the enclosure, but is switch able to a 9 volt power adapter.

On the side is a semi lfo mode. I basically added an extra 500k resistance to lower the pitch. But at these low frequency the triangle wave can can be heard and the square wave will function as a controlled voltage on / off. Added sync, triangle square switch, volume, photo resister, RCA and 1/4"outputs, and some what of a lfo mode.

This is a simple little device I made to patch MIDI information. Even though the MIDI signal is routed through a 5 pin DIN connector, it transmits only through 3 of the pins. So by converting those 3 pins over to a TRS connector you can run your MIDI information into a TRS patch bay and re patch your MIDI, which is what I did. So I have all my synth's MIDI in / out cables going into the patch bay as well as to my controllers and to my computer. So at any patch I can quickly reroute where my MIDI goes. For this I made special cables, but I also made this little box to accept regular MIDI cables and TRS cable to interface into my patch bay.