Diagnosing and attempting to fix a Yamaha DX100 – Part 2

At the end of part 1, I've established that the basics all seem ok (PCB, interconnections, power) and that basic digital logic stuff is happening. I rounded off my write-up with the following ideas for what to investigate next: Get some proper triggering from the chip enables to check for valid data signals. Check out … Continue reading Diagnosing and attempting to fix a Yamaha DX100 – Part 2 →

CD Rack Format Zynthian – Part 2

I've recently updated my "CD Rack" box to a horizontal black box, still shaped for my "CD Rack" format modules. But as it is black, and I've a black TX816, I've rebuilt my CD Rack format Zynthian with a black, PCB front panel too. Original Design Notes: CD Rack Format Zynthian. Warning! I strongly recommend using … Continue reading CD Rack Format Zynthian – Part 2 →

Arduino Direct Digital (Additive) Synthesis

This is actually a collection of previous projects with the code tidied up a little and combined to show a single sketch that can be configured for either PWM, an R2R ladder or the MCP4725 I2C DAC. There isn't really anything here that hasn't been talked about before somewhere, but hopefully this can act as … Continue reading Arduino Direct Digital (Additive) Synthesis →

Raspberry Pi Pico Synth_Dexed? – Part 6

One last thing I definitely wanted for my PicoDexed was the option for PWM output. This post is by way of a short coda detailing how to do PWM on a Raspberry Pi Pico. Part 1: Building Synth_Dexed for the Pico. Part 2: Assessing the performance and analysis of the Pico audio library. Part 3: … Continue reading Raspberry Pi Pico Synth_Dexed? – Part 6 →

Raspberry Pi Pico Synth_Dexed? – Part 5

Ok, ignore my last comment about Part 4 being my last post on this topic. I thought I ought to pull together all the hardware notes on how to build one as I haven't really written that down anywhere. So this shows the connections required between the Pico, I2S DAC and MIDI IN. Part 1: … Continue reading Raspberry Pi Pico Synth_Dexed? – Part 5 →

Raspberry Pi Pico Synth_Dexed? – Part 4

I was going to leave things at Part 3 blog-wise, and just get on with filling in the gaps in code now, but I've come back to add a few more notes. But this is likely to be the final part now. Recall so far, I have: Part 1 where I work out how to … Continue reading Raspberry Pi Pico Synth_Dexed? – Part 4 →

Raspberry Pi Pico Synth_Dexed? – Part 3

The story so far... In Part 1 I work out how to build Synth_Dexed using the Pico SDK and get some sounds coming out. In Part 2 I take a detailed look at the performance with a diversion into the workings of the pico_audio library and floating point maths on the pico, on the way. … Continue reading Raspberry Pi Pico Synth_Dexed? – Part 3 →

Arduino EEPROM Reader PCB Build Guide

Here are the build notes for my Arduino EEPROM Reader PCB Design. Warning! I strongly recommend using old or second hand equipment for your experiments. I am not responsible for any damage to expensive instruments! If you are new to Arduino, see the Getting Started pages. Bill of Materials Arduino EEPROM Reader PCB (GitHub link below). 2x … Continue reading Arduino EEPROM Reader PCB Build Guide →

Arduino EEPROM Reader PCB Design

This is a PCB version of the Arduino EEPROM Reader/Writer as described here: https://github.com/beneater/eeprom-programmer but with slight adjustments to support reading of 27Cxxx style ROMs often found in vintage equipment. Build Guide here: Arduino EEPROM Reader PCB Build Guide. Update: Since developing this board, I've found a much more comprehensive DIY board here: https://github.com/TomNisbet/TommyPROM. The documentation … Continue reading Arduino EEPROM Reader PCB Design →

Building my Oskitone Poly555

This isn't really a post like my usual blog posts. This isn't a project of mine as such or a build guide or anything. It is simply a few comments and photos of my building my Oskitone Poly555. https://makertube.net/w/a8SsXP33nymrRqNxXnbbNA I've always liked the idea of the Oskitone. I've used it as the inspiration for some of my … Continue reading Building my Oskitone Poly555 →