Music sequencer

Thread Starter


Joined Jul 7, 2019

instead of spamming the forum with yet another n00b question, i'll post it here as it involves the 555.

i'm trying to build some kind of square wave/noise sequencer (for music-making)..

this is the sequencer. it uses a 4017 decade counter to sequentially open the gates of a 4066 switch. i'm using the 4066 so i can sequence anything.


this is my trigger/clock. there is no good reason for why i didn't use the 555 timer for this. i might go for that because that seems to be what everyone else is doing... i dunno. this works very well so i might just keep it...


i think it would be nice to have the option of delaying each step (signal) out of the 4017, so (i thought) i found the way by using a 555, but i am not sure anymore after breadboarding.
it does work.. by the pot i can tune the lenght of the delay, from 0s to 2 or 3s (didn't measure exactly). i tested by using a LED on the delayed_out signal.

it seemed promising. my idea was to run every step (signal) out from the 4017 through the 555 in order to delay a high signal,,,

but i don't how or if that is even the remotely right way to go about this!

Thread Starter


Joined Jul 7, 2019
never mind that, i figured it out just by using AND gates..

R1 set as a pot (500k) and C1 as 10uF,,,,,

brings about new problems as i want the C1 to discharge quicker....


Thread Starter


Joined Jul 7, 2019
CORRECTION: Place a small signal diode (1N914, 1N4148, etc.) in parallel with R1, cathode to the input.

you mean like this? i drew it in parallel with the resistance, cathode to the input of the incoming signal. now i think you meant cathode to one of the inputs of the AND gate....
4081 signal delay.png

i think i get what is going on...

the AND gate only lets out 1 when both it's inputs are 1 and one of them doesn't get it until the capacitor is charged?

the diode is there to make sure that the capacitor only discharges instantly, current is still passed through to resistor to charge the cap.. right?

I created a thread of your very own from LEDs, 555s, Flashers, and Light Chasers . You probably noticed I like to teach. Anytime you want my attention just put @Wendy in the post and I will be flagged to read it. Works for other members too.

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thanks... makes sense.... :)

Audioguru again

Joined Oct 21, 2019
The Toy Piano project uses the squarewave from a 555 oscillator driving an 8 ohm speaker through a capacitor with a low value of 10uF. Then the capacitor cuts frequencies below 2000Hz and it produces only squeaking buzz sounds.


Joined Mar 24, 2008
I've always heard a square wave sounds like bagpipes, a triangle wave or sawtooth is probably more melodic IMO.