Hackaday.io Hackaday.io
Projects
Recently Updated Most Likes Newest Project Lists
Discover Contests Courses Stack
More
Courses Tutorials Events Hackerspaces Profiles Hackaday.com Tindie Marketplace
Sign up Log in
Close
0%
0%

Transistorless Sound Synthesizer

A home brew mini-synth idea using no transistors with the Patrick Oscillator

Dr. CockroachDr. Cockroach
Following Follow project
Liked Like project

Become a Hackaday.io member

Not a member? You should Sign up.

Already have an account? Log in.

Sign up with Github
Sign up with Twitter
OR
Forgot your password?

Just one more thing

To make the experience fit your profile, pick a username and tell us what interests you.

Pick an awesome username
hackaday.io/
Your profile's URL: hackaday.io/username. Max 25 alphanumeric characters.
Pick a few interests
Projects that share your interests
People that share your interests

We found and based on your interests.

Choose more interests.

OK, I'm done! Skip
Join this project
Similar projects worth following
2.1k views
16 comments
22 followers
20 likes
  • Description
  • Details
  • Files 0
  • Components 0
  • Logs 9
    • View all
  • Instructions 0
  • Discussion 16
View Gallery
2.1k
16
22
20

Team (1)

  • Dr. CockroachDr. Cockroach

Join this project's team
hardware
ongoing project
light logic led CdS photo resistor synthesizer sound MUSIC Mark nesselhaus patrick flett monophonic passive Synth

This project was created on 10/11/2020 and last updated 3 years ago.

Description

Thanks to a circuit by Patrick Flett, I have a idea to develop his Patrick Oscillator into a mini synthesizer. This circuit uses the same Led/Cds photo resistor pairs that I use for Light Logic and Patrick shared his circuit with me in late September 2020 when we met on You Tube.

As of now, this synth is Monophonic just to keep the circuit as simple as possible.

As with my more recent projects, this one does not use any transistors but it does perform quite well as it is. It even drives my headphones to a comfortable level so no extra amp is needed.

Goal is to make a patch panel along with switches and variable pots to make use of all possible subtle sound output combinations as well as make or modify a basic piano style keyboard of one or two octaves.

Project Logs
Collapse

  • Let the circuit bending/blending begin

    Dr. Cockroach • 11/23/2020 at 15:48 • 0 comments

    I have decided to begin blending the Patrick oscillator and other circuits to the keyboard. The circuits are mounted and just need the interconnects added.

  • Where is this heading????

    Dr. Cockroach • 10/28/2020 at 21:20 • 0 comments

    October 28, 2020 -  I am at a bit of a crossroads with this project. I will continue to explore just how much I can expand the range of sounds with this oscillator but now I also want to build a multi voice drone similar to what Sam from Look Mum No Computer fame has made at https://www.lookmumnocomputer.com/

    If you have a moment then check out his projects. All are Mad Good but I really love the Drone of his and I think I can make at least a 5 to 10 voice example. Check out his Megadrone https://www.lookmumnocomputer.com/projects#/1000-oscillator-megadrone

    And if I make a batch of oscillators then I could have a basic and messy polyphonic system in its beginning stages.


  • Testing the Theremin effect and a LFO

    Dr. Cockroach • 10/25/2020 at 13:01 • 0 comments

    October 25, 2020 - Video of current tests of the LFO and perhaps make a Passive Optical Theremin

  • First test scale

    Dr. Cockroach • 10/14/2020 at 22:09 • 5 comments

    October 14, 2020 - First test scale using the very basic keyboard. I still need to add the sharp/flat keys but this taking shape.

  • Tuning and Keyboard Module

    Dr. Cockroach • 10/14/2020 at 15:22 • 0 comments

    October 14, 2020 -  Starting the layout of the tuning pots and keyboard switches.

  • The Basic Circuit

    Dr. Cockroach • 10/14/2020 at 10:53 • 0 comments

    Here is the basic circuit I am using. Pardon my poor sketch ;-)

  • Switches for the keyboard

    Dr. Cockroach • 10/13/2020 at 21:07 • 0 comments

    October 13, 2020 - I found some very small switches in my junk box that will do for a small push button keyboard. Not ideal but good enough for testing. These were from a printer/copier that my landlord gave to me so why not make use of some of those parts. This will be a single octave from C2 through to C3 plus a extra key on the left for a knob controlled tone. Right now the oscillator has a hard time reaching C4 so going with the lower octave. Besides I love the deep rich sound this circuit has down there :-)

  • The perfect multi-turn pot ???

    Dr. Cockroach • 10/13/2020 at 12:44 • 3 comments

    October 13, 2020 -  I have had this old TV tuner board in my junk box for about thirty years and I think these 20K pots will be of great use in the tuning of the keyboard part of this project. These pots take about 100 turns for full range. Very fine tuning indeed ;-)

  • How it sounds in the raw so far

    Dr. Cockroach • 10/11/2020 at 18:53 • 0 comments

    October 11, 2020

    This is just a sample of the deep low sound from the Patrick Oscillator. Very low frequencies and sounds great.

View all 9 project logs

Enjoy this project?

Share

Discussions

Log In/Sign up to comment

Become a Hackaday.io Member

Create an account to leave a comment. Already have an account? Log In.

Sign up with Github
Sign up with Twitter
OR
Yann Guidon / YGDES wrote 10/27/2020 at 03:00 • point

I'd love to build a polyphonic one...

  Are you sure? yes | no

Dr. Cockroach wrote 10/27/2020 at 10:42 • point

Actually, I have already started on that. All I need for the single octave is one oscillator for each note. As long as I keep it simple XD

  Are you sure? yes | no

Ken Yap wrote 10/25/2020 at 05:12 • point

Cool! You should make a few and start an ensemble. As they say, many hands make light work. 🤣

  Are you sure? yes | no

Dr. Cockroach wrote 10/25/2020 at 09:43 • point

Now that would be cool :-)

  Are you sure? yes | no

Dr. Cockroach wrote 10/25/2020 at 09:44 • point

Light work.... Ooooooooo

  Are you sure? yes | no

Dr. Cockroach wrote 10/27/2020 at 10:42 • point

Light Work, I love it :-)

  Are you sure? yes | no

Yann Guidon / YGDES wrote 10/25/2020 at 00:50 • point

Doctor, you did it again !
https://hackaday.com/2020/10/24/a-transistor-less-sound-synthesizer/

  Are you sure? yes | no

Dr. Cockroach wrote 10/25/2020 at 09:43 • point

I guess so but in all fairness Patrick Flett invented the circuit, I just pounced on it as a possible passive synth sound machine :-)

  Are you sure? yes | no

Hari Wiguna wrote 10/24/2020 at 23:38 • point

Patrick Flett explains how it works in this video:
https://www.youtube.com/watch?v=fYMWZ75iO8g

  Are you sure? yes | no

Dr. Cockroach wrote 10/25/2020 at 09:38 • point

Yes, I am so glad that Patrick shared his circuit with me and now I am expanding on it to where it might actually be a very flexible synth.

  Are you sure? yes | no

Dan Maloney wrote 10/14/2020 at 18:37 • point

I'm struggling to understand how the oscillation happens. I thought it required amplification and a positive feedback loop. Going to have to dig into this one a bit more - thanks for the head-scratcher. Like the way it sounds, BTW.

  Are you sure? yes | no

Dr. Cockroach wrote 10/14/2020 at 21:01 • point

I am struggling with the concept myself. My led/CdS Logic is easy enough to follow but this circuit confounds me a bit ;-)

  Are you sure? yes | no

Ken KD5ZXG wrote 10/15/2020 at 19:33 • point

if not inverting, perhaps just a relaxation oscillator.

  Are you sure? yes | no

mh-nexus wrote 10/14/2020 at 17:48 • point

Hi, interesting project.

I assume you meant this Patrick Flett: https://www.youtube.com/channel/UCdY0rnioc1twUgD6JwpuXvg


Maybe saying a bit more than providing a schematic would help to better understand how you want to make a synthesizer. Or do you just aim at making some sine wave sounds?

  Are you sure? yes | no

Dr. Cockroach wrote 10/14/2020 at 21:00 • point

Yup, same person, he found my Light Logic videos and we have exchanged some ideas and he sent me his schematic. This is my first real attempt at a synthesizer of any kind and this is the start of a very interesting build if I can maintain the transistorless aspect of it. The very simple keyboard is now working and tuned. I will post as I learn more and develop this project

  Are you sure? yes | no

Dr. Cockroach wrote 10/14/2020 at 21:08 • point

I would like to add loops and feedback as well as filtering but that will still be a step by step adventure for me :-)

  Are you sure? yes | no

Similar Projects

Under this project I will document a process of converting cheap scientific calculator into cool programmable one :)
Project Owner Contributor

HACKACALC

SHAOSSHAOS

The 2018 Hackaday Prize
An artistic ecosystem of analog electronic sound generators
Project Owner Contributor

Hacking Nature’s Musicians

Kelly HeatonKelly Heaton

The 2015 Hackaday Prize
A chorded keyboard with a built in mouse
Project Owner Contributor

One Handed Keymouse

Patrick TaitPatrick Tait

A no-touch musical keyboard
Project Owner Contributor

CoViano

MaBe42MaBe42

Does this project spark your interest?

Become a member to follow this project and never miss any updates

Going up?

About Us Contact Hackaday.io Give Feedback Terms of Use Privacy Policy Hackaday API

© 2023 Hackaday

Yes, delete it Cancel

Report project as inappropriate

You are about to report the project "Transistorless Sound Synthesizer", please tell us the reason.

Send message

Your application has been submitted.

Remove Member

Are you sure you want to remove yourself as a member for this project?

Project owner will be notified upon removal.