simple 8 step sequecer for SL

[Clack]

wow that is fantasic , i didnt expect the sound to be so clear. whats the toy ? ( and may i add what a sick toy it must be, some kind of bar fighting toy? )

[dnny]

yesh thanks for your kind words.
but i don´t know whats wrong whit it - it sounds great but to control it - its nothing i planed. maybe its the crappy toy chip that is adding chaos to this thing - maybe it works nicely whit SL we don´t know - i don´t have my SL ready yet so one of you needs to test this whit it

but yes I'm very pleased whit the results i like randomness and uncontrol very much. so I'm not going to fix this "first attempt" at all - lets just leave it like this. here is another sample for you who liked the first one

i will try to get a pic of the toy when i go and visit my sisters (and i will try to look for more abandoned noise-toys)

daniel

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[Pehr]

Is it hard to scale it down to a 4-step sequencer? With only one 74HC4016, right?

[Pehr]

Another question I have is why both b and e on the NPN-transistor is connected to ground? If I remeber right there have to be a voltage over b-e to open c-e, right?

[Clack]

[dnny]

[Clack]

hi sorry for a general electronics question , but why do the LEDs have to go to ground? its somthing I always wonder through my lack of reading books

[Macaba]

The IC gives out a positive voltage (whatever supply voltage you give it) to the LED, and the other side needs to go to 0v AKA ground. Like hooking it up to a PP3 battery. The + is regarded as 9v, and the - is 0v AKA ground.

[Pehr]

Could there be a pot just before CV out to pitch all the steps simultaneously?

[Pehr]

Could one timer be used for more than one of these sequencers at a time? like a multi-channel?

[dnny]

[mosc]

You probably should put a buffer amplifier on the output of this circuit because different valuses of loads will change the voltage.

To answer Pehr's question, it's not a great idea to just put a pot in series with the output of this devices because it will load the output and also, you can only attenuate the output. This will have the effect of changing the scale.

If you want a transpose, you should use a mixer.

I'd suggest using one opamps, for a mixer of the sequencer CV and a a buffer (from a pot of any other module) and one to invert and buffer the mixer. You will have to switch the connections of the step pots around because mixers invert, but that's no big deal.

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[Pehr]

Aha, I see. So the seq. CV and the transpose CV (from a keyboard CV?) is added together, right? resulting in a transpose of the sequence...

[mosc]

Yes. The transpose signal can be a keyboard, and osc, LFO, or even just a pot.

Add more 100K resistors on the left side of the drawing and you can add more things to mix in.

[Clack]

yeh i think if you plug the sequencer into both oscilators and adjust the osc pitch while sequencing you get crazy layerd results

[Macaba]

I'm going to draw up a PCB for this, i just need one thing confirmed:
I don't have any DIP switches around (AKA Piano switches) could somebody confirm that the pins on the bottom of this is arranged like a 16-pin DIL package?

[Uncle Krunkus]

I'm not sure what you mean by DIP switches Mac.

[Macaba]

Indeed, after checking, it seems they are called DIL switches which answers my question rather well. Seems getting "merry" at christmas hurt a few brain cells.

[Uncle Krunkus]

Ya Dil

[dnny]

[Macaba]

I have not breadboarded it yet, but it looks like I will then, and i'll test it out in every way I can to try spot bugs.

I've been trying to snatch minutes here and there to build a soundlab, and its my intention to add on the sequencer so when I get to that stage, expect the sequencer pcb. (Hell, i might get bored soon and do it tonight )



Mac

[Uncle Krunkus]

I've been playing around with this circuit and have noticed a couple of points which aren't obvious from the current schem.
1. The clock inhibit (pin13) needs to be held low otherwise it will float which may inhibit the sequence.
2. The reset on step switches do need to be a rotary so that the reset is held low except when you want it activated. Otherwise you'll get a floater which will repeatedly reset when you don't want it.

I'm about to add a second 4017 and a 4011 (4*2I-NAND) to cascade them for a 16 step.
Looks like I'll be doing a stripboard of this soon.

[Uncle Krunkus]

Well I went with a 4081 (4*2I-AND) though I'm sure you can get similar results with some nand gates.
Anyway, it's flashing through a 16 step sequence even as we speak, er,,..... type.
I'm gonna have another look at the schematic publisher to see if I can draw it for ya.

[Macaba]

Ok, go for it. I've pretty much drawn up the 8 step as a PCB, It could be nice to have the option of 16 steps on the same pcb (even though its alot more IC's!)

[Macaba]