Skip navigation

Category Archives: sequencers




here is a little jam to test the possibilities of my recently finished step sequencer…this little gadget is so much fun, and opens up my head of possibilities…i have to write a proper post with circuit and instructions on how to build it i will just say for now that is made with a single 4017 that can trigger 4 different channels on each of the 10 possible steps.

here comes the sound…

…on the video I’m playing the sequencer and the SP-404 sampler trying to match tempo…and the sp404 is also filtering the sequenced sounds at times…and the drum pattern at others….the step sequencer is triggering the sounds of a toy circuit which i modified adding also pitch and distortion controls….plus the jacks connect the 4 channels of the sequencer to the desired sound bank on the toy…


this are some images of the process of building the 4017 step sequencer and a little circuit diagram…the construction was not difficult but  tedious….

9volts 2009


let’s start with a video:

(thanx again for the recording to LucySombra):

I made this project a year ago, using the mechanics of  (his master’s voice) old Victrola, found on the streets of Barcelona, by jan (thanx again man) and brought to me to salvage it’s still usable parts, the poor thing had ended it’s life as a record player on the trash, needle and arm missing, cone sound missing, etc… BUT the only one thing remaining, and the most important to me was the cranked  spring engine, with it’s old school system to keep speed regular…

seqenciador mechanico

The result is a very interesting cranked beat sequencer,  it has four radial channels, with 24 steps each, each step is one hole on the plate, where small plastic pieces (from “mastermind” game, also trashed out from bcn) can be placed to trigger a sound. Each channel is aligned with a momentary switch which when contacting one of the plastic pieces triggers the sound assigned to that channel.



There is two different circuits that can be used interactively with each other. On one side a simple drum toy with four drum sounds, some basic bending like pitch control (for all the sounds at the same time), and body contacts for distortion mode 1 and 2, and in the other side a simple pitch controllable oscillator circuit for each channel, (made with just one  4093).


it’s is an open sequencer because any source can be triggered by plugging it’s push button trigger poles  to one of the rca connectors on the back, that is how the drum toy circuit encased in the box is triggered. that also means than the sounds triggered by each channel can be easily swapped on the fly by others by just plugging the desired source on the desired channel.



on the other hand both circuit’s have independent volume control to be able to tune the mix levels, some times oscillators can be loud… the yellow buttons also trigger each channel for longer manually operated notes.




DRONE sounds SYNTH, cased inside an old router box. Chaotic but under control.


The circuit for this instrument is quite simple, four 555 in astable configuration gating and four oscillators made with just one 4093.


click to enlarge

The interface is arranged as four channels across,each one has three switches and two potentiometers, and LED showing it’s state:


So for each channel, the first pot (50k) controls the freq of pulse coming out from the pin3 of each 555; this signal can be routed to main out (resulting on a pulse beating oscillation) or to gate each of the 4 oscillators made with the nand gates of the 4093. the second pot (1M) controls the pitch of the gated oscillators on IC 4093. the switches allow for some tweaking on each channel, either pulse ore gated/osc mode,also the indispensable channel on/off, and finally the third switch connects the pins 5 of the 555 (voltage control?) to the main out resulting on some interesting broken rhythmic patterns…for some magic of electronic randomness…All switches positions can be use combined into several different modes,and like always (I’m not an engineer) the oscillators affect and modulate each other..sometimes beautiful harmonies occur inside the rhythmic pattern…drone2



The result is an instrument that is fun to play, because while it has it’s random magic sound remains totally controllable.

Here is a video of the DRONE in action performed by 9volts & ChairB and recorded by LucySombra.

video of PyR 2009 | PyRformance Alba G. Corral + Nikka

Nikka is owner and user of Drone Synth