Sequencer mods

[tomtom]

I try to wire something from the Geo random LFO article one years ago, I think. It was a simple circuit with a CD4051 as a eight poles switch and a CD4060 as a binary counter.
 It works great after some messing with pots and voltage values and  it drive my phaser nicely.

 I was wondering if I could change the number of sequence from 8 now to 4 or even 2 (LFO simulation)?
 Does the counter (4060) able to reset the 4051 or does the 4051 need something to be wire to its reset pîn ?

 I look to some datasheet but logic seems to be a nightmare for me !


 Moreover, I found another sequencer (geo too !) with random capabilities (nice !) but I don't know how to choose R and C for the 74c14 (oscillators and speed control).

 Here is the link: http://www.geofex.com/Article_Folders/LFOs/psuedorandom.htm

 If you have any idea...
 
 Tom.

[Maneco]

the 4060 counter drives the a,b and c select inputs of the 4051 ( pins 9,10 and eleven,i don't have the datasheet right now)..so to make it count to four,just add a switch that connects the c line to positive or to the 4060,and the 4051 will cicle only the last four outputs...the same with counting up to two,just wire two of the 4051 inputs (b and c to positive,and the 4051 will select just the two last outputs)

BEST!!!
Maneco

[tomtom]

Yeah! That's quick !

Is it possible for the 4051 to circle three or six steps?

Thanks.
Tom

[Maneco]

Hi,
well,tha easiest way to add any number count is to add anothe 4051 with the same addres lines connected,then the common input (pin 3 )tied to positive,and the outputs connected to a selector switch,the common pin of the selector switch connected through a 1n4148 diode to the reset pin of the 4060,that pin should be pulled down through a 100k resistor to ground.
i'd ALSO USE THE outputs of this  4051 to drive leds,through  2k2 resistors...makes sense?

Best!!!!
Maneco

[tomtom]

It make sense, thank you.

 I think my 4060 reset pin (12) is wired to ground without any resistor...

 If you mean I need to adress V+ to the 4060 reset pin, should I choose to send output 7 of the second 4051 to this pin for a six steps motion?

 If the input of the "main" 4051 is already wired to the V+, why not connecting in this case the seventh output to the 4060 reset pin via the diode?

 Best regards.
 Tom

[Maneco]

if the main 4051 has the common connected to positive,you don't need another one,just disconnect the reset pin of the 4060 from ground and put a pull down resistor from pin 12 to earth,and add the diode from output 7 of the 4051,or the step selector switch

Best
maneco

[tomtom]

I found this because of the random option :

 http://www.geofex.com/Article_Folders/udrand.htm


 Do you know if it's possible to have such randomness with the 4060 and if it's not possible, how I may choose Rc for the oscillators? (74c14)

 Best !
 Tom

[moosapotamus]

'Scuse me for buttin' in...
Cool thread, and I'm thinking of a couple questions, too...

Would it be possible to string a couple of 4051s together to get a 16 step sequencer? How?

Could two 4051s be synced to run in parallel? Would you just connect pins 9, 10, and 11 from one 4051 to the other, and connect to either a 40193 or 4060 in the same way?
(Might sound cool to modulate LFO speed and wah frequency simultaneously, for example.)

How would LEDs be added to indicate which step is active?

What about putting toggle switches in for each step, allowing you to insert "rests" by switching off some of the pots?

Thanks!
~ Charlie

[Maneco]

Hi,
yes and yes :lol:

you can run two 4051 in parallel,just wiring together the 9,10 and eleven pins.
For 16 steps,it`s easier with the 4067,but some time ago i cascaded two 4051 using the chip enable pin ,and an inverter from the fourth output of the 4060...
to drive leds,just connect the pin 3 of the 4051 to positive,and the outputs to 8 leds and eight 2k2 resistors,the other pin of the led just goes to ground

best!!!!
Maneco

[moosapotamus]

Thanks!
~ Charlie

[Maneco]

Hi,Charlie,
the toggle switches idea reminds me of a pattern tremelo i built in 1989,cool days,i was 20....also added three rows of switches driving analog bass drum,snare and cymbal...sad,my ex wife throw some of my inventions away when cleaning  :cry:

Best!!!!
Maneco

[moosapotamus]

Too sad! That must have been a fun little gizmo to play with!

~ Charlie