simple 8 step sequecer for SL

[dnny]

so here is what i suggest:
*[this is the first version - scroll down to see resent versions]*

it uses
74HC4017 Johnson decade counter with 10 decoded outputs,
74HC4016 Quad bilateral switches.
and 555 timer

the value of the capacitor on 555 timer circuit is still unknown but i will try and breadboard this soon to see if it works, and then i will know the value of the capacitor.

there will also be option to add leds to every step and to reset on other than the last step

if you see any mistakes i made, please notify so we can make this work
hope this works
and if you want to ad something to the schematic. i can post the schematic in .sch-file (RJWsoft schematic publisher)

daniel

---

seq8.gif
Description:
Filesize:	18.79 KB
Viewed:	92282 Time(s)

---

[Macaba]

This is excellent! I've been wanting to make lots of simple sequencer's for my modular synth, and this is just the ticket! I've been thinking of how i could do it, but didn't have the knowledge to work it out, but having gone through your design, it makes perfect sense, and is very logical!

Its a shame that only the 555 chip is in my IC collection, i'll just have to put them in my next order.

Will be watching this thread closely, 'Notify me when a reply is posted' Check!

[v-un-v]

those diodes could be led's too?- as you are running 4016's off a 4017? :D

Or are they meant to be led's? :oops:

[dnny]

[Afro88]

Is there was a way you could chain 2 of these for a 16 step?

[v-un-v]

[dnny]

[v-un-v]

[dnny]

just had my proto board set up - and here it is
flash animation

so here is some comments:

on the first schematic there is a mistake - : connect the cathodes of the leds to ground.

the cap on 555 timer is 100uF.

there is a need for fine tuner for the clock circuit.
(the range is very wide)

if you want to "walk" the steps manually connect the point A to ground via momentary push button.

there is some problems resetting the steps (if you want to reset before it hits the last step)

i will draw new corrected schematic soon

daniel

[jksuperstar]

dnny- you could use a counter (like the HC163), that feeds 2x 3->8 decoders (HC138). Use the 4th output of the counter to select which decoder is used.

The benefit of this scheme, besides having 16 steps, is the fact that 4 switches into the counter can force it to be "presetable", so the counter *starts* at whatever number you choose. This means the length of the step sequencer is programmable This preset is loaded on reset. Use the "TC" output of the 163 to reset the counter itself. Since the 163 is synchronous reset, everything happens on a clock edge, an stays in beat.

[mosc]

Better yet, use the 74--193 chip. It has preset and also up/down.

That you are using the bilateral switches is very cool. Instead of just switching a voltage to the output posts, you can hook up 8 audio sources and switch between them.

[dnny]

thanks guys i took a look on the suggested ics data sheets - but im in the very beginning of this electronics world - that i need to ask fore more detailed answers -or maybe a schematic to illustrate how to connect the things - thanks

now i have made some improvements to the simple 8 step sequencer:

DIP switches:
- to gate on/off
- and to reset on step

manual step forward button

when all potentiometers are 100K then there is no need for fine tuning.

if you want to reset before it hits the last step just close one switch from the reset DIPswitches (but just one - if you close multiple switches it results as weird blinking - what can be of course used as an effect)

(should i remove the first schematic?)

mosc: i was thinking to ad some Schmitt trigger-based simple osc´s to the bilateral switches. so that on one step i might have two osc´s and on the other four or something... that might result something interesting...

i am so exited of all this things that i learn by experimenting and asking.

thanks for your patience i really appreciate the lessons i get here at EM-forum

daniel
[edit:added comment on the reset switches]

---

seq2.1.gif
Description:
Filesize:	20.62 KB
Viewed:	92127 Time(s)

---

[v-un-v]

Dnny, I don't want to state the obvious (I will) but shouldn't the reset switches just come from one single rotary? All those switches would be expensive and pointless. The gate switch idea on the other hand is excellent.

hmmmmm.....sequencer.........

Just need to do one thing at a time- get my friggin SL finished!

PS I don't recommend nicotine stick-on patches. These things have a far worse withdrawal than plain cigarettes. It's been two months now of smoking no tabs. Now I'm addicted to the patches!!

There howabout that for surrealism on a Saturday afternoon? I'm so spaced-out!

[blue hell]

[mosc]

No need to remove the first schematic. The forum is a good historical document. It's neat to see how things evolve over time.

As for the bilateral switches: you can use normalizing jacks. Without something plugged in, it will work exactly as you have now. Plug in a signal and it works as a multiplexer. I would run the jacks throught the same posts. Not hard at all. Imagine plugging 8 radios into this beast.

[Uncle Krunkus]

I did a bit of experimenting with cascading 4017's and you can create any number of steps you like, it involves using AND gates on the clk inhibit/enable pins so that the last (unused) step on the first chip inhibits it from stepping back to the start and simultaneously enables the stepping of the second chip. The first output of which is not used as this is where the second chip rests while the first steps. This principle should allow more chips to be added to the cascade, but as far as I remember it gets more complicated the further you go (multiple input AND gates etc) and you end up being better off using other chips.
Great idea circuit idea, especially for people who already have lots of 4017's hanging around doin nothing!! Like me! I've just got to get my soundlab built so I can start to experiment with all this stuff.

[dnny]

[Uncle Krunkus]

I realised this arvo that I have a collection of SPDT mini toggles that are centre off. When I have a go at this sequencer I'm going to use those so that each step has the choice of CVonly(centre), +Gate, and last step all on one switch. Combined with the cascaded 4017 idea to give 16 outputs this would result in a very cool and still simple sequencer. Next thing is to dial up different banks of flip flops with a rotary and we have almost built a Dr Rythm!!

[Uncle Krunkus]

Here's a link to a pdf data sheet that includes how to cascade 4017s.
It's near the end of the pdf.

[Macaba]

Maybe i'm blind but i can't see a link.

[Pehr]

What voltage is this sequencer running on? +/- 9V or +/- 12 V ?

It says that point B should go to point 2 on R2, but is it possible to make it work on the ext. gate in on the SL?

[Macaba]

I believe that the following figures are correct when researching:

The 4017 chip can run on 0, +3 - 15v
And the 4016 can run on 0, +0.5 - 11v

So its safe to say that +9v is ok, and +12 when used with a pair of voltage dividing resistors for the 4016 to reduce voltage to 9v.

[dnny]

[Pehr]

0k, great

Another question I have is how this sequencer is started/stopped? And how the manual step fw works

[Macaba]

Put a switch on the power to switch it on or off, or experiment with putting a switch on the clock.