Fun slide whistle synth toy


[Dino] recently sent us some info on his latest project, a 555 timer-based slider synthesizer. The synth was built to emulate the sound made by playing a slide whistle, and also as an entry into the 555 Design Contest, which is quickly coming to a close. If you’re not familiar with a slide whistle, just spend a few minutes on YouTube looking for clips of Sideshow Bob – it’s ok, we’ll wait.

The circuit is pretty simple, though the implementation is quite clever. While traditional slide whistles require the user to blow in one end, this electronic version operates using a LED and photo cell. When the main switch is closed, the 555 timer is activated, and a tone is produced. The pitch of the tone is controlled by the LED as it slides in and out of the tube. The more light that hits the photo cell, the higher the pitch, and vice versa.

Continue reading to see a quick demonstration of [Dino’s] slide synth, and be sure to check out his other 555 contest entry we featured a short while back.


  1. Hirudinea says:

    Worst trombone ever! ;)

  2. mess_maker says:

    lol @Hirudinea

  3. Alan says:

    Love it! Very simple but an awesome implementation. Plus a very funny video. Well done!

  4. strider_mt2k says:

    First you got points for sleeping kitty
    Then the project absolutely rocked
    THEN a double shot of the Star Trek theme?

    I like it!

    I like it a lot!

  5. Dino says:

    I thought this would be a great project for parents with kids interested in electronics to build together. :) …and as always, I had tons of fun making it!

  6. nwndarkness says:

    Did he say “100uF to take out the AC”??? I’m pretty sure caps take out DC…

  7. egasimus says:

    That’s cool (: One could add some sort of ADSR VCA or VCF triggered by the same switch (would have to be another kind of switch though, those micro-buttons are SPST) for a more realistic timbre. And mark the note positions on the stick so one could play in key :)

  8. echodelta says:

    Two telescoping tubes would give a limited but smooth range with fine control. The tape wrapped stem is sloppy and catches in hole.
    Don’t mark notes anywhere. Make it playable with smooth operation then play a lot with backing tone. You will pick it up. Listen!
    This is one real instrument that works with the 555, as it’s pitch stability is poor with keyed notes.

  9. Necromant says:

    Hm… nice cat…

  10. CG says:

    Love the light geiger idea.

    Cool demo. Eat your heart out Captain Kirk.


  11. petey twofinger says:

    cool lil project , great job !

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


Get every new post delivered to your Inbox.

Join 97,759 other followers