It’s Paul from Paul’s Engineering space, and I’m adding another project to the variety I am working on. As you can tell from the title I am recreating a project from Electronics Australia 1981 October through 1982 January issues. Alot of this work has involved finding modern equivalents of the chips used in the project, I have been able to either find modern versions, or in the sense of the tone generator, I have recreated it as an oscillator board, as the original chip is no longer made, and the purpose of this project is to recreate it using currently available hardware.
Departing from the original piano’s design, I have designed a mainboard, utilising PCI-e connectors, so various parts of the piano can be on daughterboards, I’m only using PCI-e connectors as they are readily available and cheap! But will also permit changes to design in a way that once I have fully completed the initial project and have defined the projects standard. The purpose of going down this path, it will give other individuals, the opprtunity to make there own wave shaping boards, and get different sounds out of the piano.
This project has been a huge undertaking and is just as big as my extruder project.
So feel free to discuss with me my efforts so far, I’ll have video published once I have finished designing the new mainboard.
You might need to make sure that they are still “readily available” downstream a bit and the “cheap” bit mostly does not pay dividends if there are many hands handling them. Mostly they would be plug in and forget. The number of guaranteed insertions might surprise you.
If it were me and I had any trouble in the future the “cheap” bits would be the first place I would look.
Just Googled those connectors and there seem to be lots of different ones around so you should be OK there. Just that I am not familiar with PCI-e terminology but the ones in the pictures look familiar. Probably knew them as something else when I was working (25 yrs ago). A lot of connector terminology seems to have changed over the years and I am the first to admit I have not kept up. Have had no reason to unfortunately.
Cheers Bob
PCI-e Connectors are PCI-Express slots as found in a modern motherboard, so they will be available for a while! And the reason I chose them as they are used for expansion cards, just in this sense not being used in a computer.
I have not found any details of the project so not sure if this is relevant. Some time ago now I developed a program to make an ATMEGA328P performs like a MK50242 or equivalent Top Octave Generator IC driven by a 2MHz clock. It generated simultaneous frequencies C#8 4434Hz thru C9 8368Hz on 12 pins. At the time I didn’t know much about note accuracy so reproduced what the MK50242 did. However, there was room for improvement which was not undertaken as nobody seemed interested. This included improving the note accuracy (if accepting a few nanosecond jitter on the square waves), changing the scale on the fly, and by implication being able to shift all frequencies up and down by a small margin (bending or vibrato). This was done with the standard 16MHz clock crystal so even more could be done with a variable clock.
Probably too late as it sounds like you have done most of the work already.
I’ll have a website up in the coming days, this will list relevant links to my GitHub, and a copy of the original project from archive.org as it can be hard to find copies of periodicals from 40+ years ago.
Good Idea with the ATMEGA, but the main purpose of the recreation project, is to first recreate the original keyboard, and move forward from there, by all means, your more than welcome to create a tone source board from the project, once I have made the standard layout available, your free to design a daughter board to work with the keyboard. That’s the purpose of this project, bring to life a 40 year project, and continue to expand it.
There are PDF schematics available if people don’t have KiCAD to open the KiCAD project. The Piano Card is still a work in progress (No PDF file yet), already have close to 1500 components on the board design may have to be split it over two boards. Also due to the level circuitry on the board, I’ll have to make the design decision to use a smaller SMD component size from 1206 to potentially either 0805 or 0603, these sizes, would also be the smallest I’d feel comfortable working with.
Also due to the nature of the design, I’ll be able to design a MIDI interface card for the piano once I complete the initial project.
Actually its 73 note, in the current work in progress piano card, is where the individual notes get generated, the tone generator card, only generates the base 12 notes which are used to create the individual 73 notes, through a mixing array using diodes and a a binary ripple counter, producing a square wave at the required frequency with a mark space ratio of 25%. This then goes through the voicing and envelope filters to produce the piano output.
And yes you found the original article, I have had to do a lot of transposing of the design, the majority of it is largely unchanged, except for about 10% of it, as some specific packages are no longer manufactured, and I have had to redesign these sections with modern equivalents, mainly in the voicing board. Plus I’ve also made changes so it can be expanded unlike the original project. Also like I said getting alot of discussion on the element14 forums as well.
I’ve been going down the youtube rabbit hole on projects like these and they’re super fascinating. Maybe you’ll find some inspiration from this channel as well!
Sorry I have not posted any updates, or had continued progress, I’m currently dealing with some mental health issues at present, but once I am feeling better I’ll have another update on the project
If projects don’t fit into the self-care, they can wait @Celcius1 - take care of yourself
we appreciate ya, and hope things are going a little smoother soon.
Your dedication to this project, as well as your extruder project, certainly speaks volumes about your passion for engineering and innovation. I am looking forward to seeing the new mainboard design and hearing about the progress you make.
@Michael thanks for the vote of confidence, I’ve had a lot of things catch up with me, and caused me to loose my recently acquired job I got at Prominent Hill. I have autism, and been in the midst’s of an autistic burnout. Plus other stresses, including how to figure out how to pay off a the Sony Camera I got, but I had the decent job at the time.
I was only recently diagnosed with ADHD, and it’s as if there’s no end to realising all the issues that come as a result of it…
What would be nice, is if there were some workplaces for spectrum-only peeps… just imagine. Although I guess if you were lucky enough to find a job that’s close to your hobbies, it would be largely self-selecting that way…
@Kimmo hey mate thanks for the support, I’ll have some more content out soon, once I can stay focused to edit the needed videos. I just need to see if I get support from people sharing my content so the YouTube algorithm will promote my videos
This is a great project that you’re diving into and I will keep a close eye on it. I like to see Pix has already found his way here sharing that article. How I wish new pianos were still around $2000. I’d like to do something similar someday as I am massive fan of Ben Bloomberg’s harmonizer.
I’m glad I’ve jumped in to have a read this and to echo all the supportive comments so far, you come first. I am looking forward to further delving into some of your other creations soon.
@Jack thanks for the vote of support, I just finished recording a video today which I’m currently editing, I go over the upcoming videos, and then I talk in length about what happened to me in 2023. And also go over other things relating to my autism.
The tone generator board looks like there are twelve oscillators each of which would need tuning. The ATmega328/P solution I mentioned before could provide those outputs locked to one oscillator. I am a programmer, not a hardware designer (although I have dabbled) but it looks like one ATmega328/P could replace all those oscillators and all the associated components. Would the 0-5V output drive a 4069?
As it is written, it generates C#8 4434Hz thru C9 8368Hz from a 16MHz crystal (the default on the Arduino Nano board). Changing to a different crystal could lower this, or (and I haven’t looked at this in detail) the program may be rewritten to produce the lower frequencies from the default crystal.
@Alan73922 this is a good idea, but I would use it to recreate the original AY-1-1012 chip and not the full set of tones, as the tones are generated from circuitry on the instrument board. So I would use to just generate the base tones that the original chip generated.
I’m excited to see more updates!
