Author Topic: Wouldnt this be a better IC to base a sequencer on?  (Read 3047 times)

nelson

Wouldnt this be a better IC to base a sequencer on?
« on: February 10, 2006, 09:47:14 PM »
http://www.semiconductors.philips.com/acrobat_download/datasheets/74HC_HCT164_3.pdf


Wouldnt it be possible to get a stepped, psuedo random, bounce +, pattern sequencer from one of these chips?

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R.G.

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #1 on: February 10, 2006, 10:13:04 PM »
Better than which?

The
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

nelson

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #2 on: February 10, 2006, 10:55:15 PM »
Nevermind......

shouldn't have used the word better...

 :icon_lol:

I don't want to criticise anyones design, the main reason is, I couldn't do any better.

I am just thinking looking at the vanishing point(+2) and your circuit on geofex there must be a relatively simple way to get atleast 8 stages and all the options stated in the thread opener.

Perhaps not with this IC.

I am looking to build an analog sequenced/random, note generator/arpegiator

Ideas on any section would be helpful.
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Winner of Mar 2009 FX-X

R.G.

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #3 on: February 11, 2006, 12:01:11 AM »
There was no offense taken, I assure you.

The problem you're facing is that the functions you want are all not contained in the same simple ICs, as the simple ICs were intended to do specific, straightforward logic functions. We're actually semi-perverting them to get them to do the sequencer stuff at all.

The real answer is a chip that you can tell "Do this..." and it's complex enough inside to do it. A microcontroller.

Doing a microcontroller program is a big step to get over, but once you do, there's a kind of freedom to make it do whatever you want. For instance, one $2.00 chip in this application would:
- read a speed pot directly
- read a selector switch for what kind of operation you wanted - stepped, random, bounce, etc.
- do the selected operation.

The details of how random the random is, what kind of bounce, which direction to sequence, etc. are limited only by your ability to tell it "check the pot reading; turn that into a timer tick rate; now go do the next step; put that out on the output pins; go back and read the pot; etc."  My favorite setup is to program the uC in BASIC to to the stuff. It's fast, and relatively simple. I debug the apps by running them in simulation until they work mostly, then put them into a breadboard/plugboard to wring out. Mostly they work the first time.

Or, if we're being completely honest, mostly they work by the fifth or fifteenth time - so I'm not the best programmer.

Any implementations with hard logic like the 74xxx or CD4xxx series is going to be a compromise in functions, limited by what the chips were intended to do, and by how much that can be perverted.

There is an ideal chip - it's a PIC or its ilk.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

nelson

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #4 on: February 11, 2006, 12:22:19 AM »
I am not ready to take that step, I would rather become more competent in analog design before I venture into the digital realm.
Besides, digital is far less accessible.
The pattern and bounce functions arent really necessary for my idea.

a VP2 should be fine, I guess I cant have my cake and eat it too with analog.

I think I will etch a VP2 board and breadboard some interesting oscillator circuits, see what I can come up with. 

« Last Edit: February 11, 2006, 12:26:31 AM by nelson »
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Paul Perry (Frostwave)

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #5 on: February 11, 2006, 01:53:56 AM »
Wouldn't the LM3914 be better, if you are microprocessor adverse?
Just run the 10 outputs via pots to a summing amp, and feed a LFO to the input.
Triangle in gives bounce, saw gives foward repeat, sample and hold of noise gives random.
I'm sure I saw this somewhere.. havn't built it myself though.
« Last Edit: February 11, 2006, 02:18:34 AM by Paul Perry (Frostwave) »

The Tone God

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #6 on: February 11, 2006, 02:47:27 AM »
Wouldnt it be possible to get a stepped, psuedo random, bounce +, pattern sequencer from one of these chips?

Stepped: Yes, but you are going to have to clear the data on start up and clock one bit in hi. Tricky to do.

Random: Yes but once again it will require some logic to keep things working properly.

Bounce: No. There is no directional change control. You would need to do some nasty clock/data manipulation.

Pattern: Yes but once again it will require some logic to keep things working properly.

Also that IC will need to have it's power supply regulated if you plan on using a 9v. Its really intended to be used at 5v.

a VP2 should be fine, I guess I cant have my cake and eat it too with analog.

I think I will etch a VP2 board and breadboard some interesting oscillator circuits, see what I can come up with.

You can but you have to do alot of baking. ;) Playing with the oscillator won't do much except maybe reduce clock noise. The oscillator just drives the 4017. You could use just about an clock circuit.

I was going to do some tweaks to the random function to maybe get rid of the opto but I haven't got around to that. I also have another board laid out using the 40106 instead of the 4093 that has the add feature of a seperate clock LED whos which brightness is not governed but the pots. I had a few other things too but I can't remember right now.

Wouldn't the LM3914 be better, if you are microprocessor adverse?
Just run the 10 outputs via pots to a summing amp, and feed a LFO to the input.
Triangle in gives bounce, saw gives foward repeat, sample and hold of noise gives random.
I'm sure I saw this somewhere.. havn't built it myself though.

I actually did attempt something like this awhile back but dropped it. The LM391*s are current hogs and don't deliver "clean" outputs. The actually leak into each other to prevent staggering between outputs at transistional levels. Besides after you spend all your time with all those LFOs you could have done this with far less gate logic.

Andrew

nelson

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #7 on: February 11, 2006, 11:18:18 AM »
a VP2 should be fine, I guess I cant have my cake and eat it too with analog.

I think I will etch a VP2 board and breadboard some interesting oscillator circuits, see what I can come up with.

You can but you have to do alot of baking. ;) Playing with the oscillator won't do much except maybe reduce clock noise. The oscillator just drives the 4017. You could use just about an clock circuit.

I was going to do some tweaks to the random function to maybe get rid of the opto but I haven't got around to that. I also have another board laid out using the 40106 instead of the 4093 that has the add feature of a seperate clock LED whos which brightness is not governed but the pots. I had a few other things too but I can't remember right now.


Andrew

I actually meant play with oscillators as a note/noise making circuit. Leaving your circuit as is. I dont expect to get anymore out of the 4017 than you have managed to do.

I am thinking of a similar sound to a S+H with a frequency tweakable noise source. Effects loop for the tone/noise + mix between the generated noise/tones and straight guitar sound.  Perhaps using a 555 or a 4046, or maybe a simple VCO.

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Winner of Mar 2009 FX-X

christobean

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #8 on: February 11, 2006, 11:47:41 PM »

My favorite setup is to program the uC in BASIC to to the stuff. It's fast, and relatively simple. I debug the apps by running them in simulation until they work mostly, then put them into a breadboard/plugboard to wring out.
this may be a stupid question, but how do you go about getting the program onto the chip?

R.G.

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #9 on: February 12, 2006, 12:15:58 AM »
Quote
this may be a stupid question, but how do you go about getting the program onto the chip?
Not a stupid question. One of the pins on the chip sets it to accept writing into its memory when you raise the voltage higher than normal. There is a special set of voltages and timing to program the bits inside to do what you want.

I use a programmer circuit that I bought that plugs into an USB port and programs the chip. There are PIC programmers as simple as a few resistors and diodes connected to a parallel printer port, or more complicated and faster ones. I think my programmer cost $35.00.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

troubledtom

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #10 on: February 12, 2006, 11:16:29 AM »
Quote
this may be a stupid question, but how do you go about getting the program onto the chip?
Not a stupid question. One of the pins on the chip sets it to accept writing into its memory when you raise the voltage higher than normal. There is a special set of voltages and timing to program the bits inside to do what you want.

I use a programmer circuit that I bought that plugs into an USB port and programs the chip. There are PIC programmers as simple as a few resistors and diodes connected to a parallel printer port, or more complicated and faster ones. I think my programmer cost $35.00.

RG, would it be too much to ask, for the ABC"s of pic for fx . also , a basic idiot setup. then a few of us could get the same setup
and help each other out?
      that would be very kind of you.
                   peace.,
                      - tom

nelson

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #11 on: February 12, 2006, 01:03:13 PM »
Quote
this may be a stupid question, but how do you go about getting the program onto the chip?
Not a stupid question. One of the pins on the chip sets it to accept writing into its memory when you raise the voltage higher than normal. There is a special set of voltages and timing to program the bits inside to do what you want.

I use a programmer circuit that I bought that plugs into an USB port and programs the chip. There are PIC programmers as simple as a few resistors and diodes connected to a parallel printer port, or more complicated and faster ones. I think my programmer cost $35.00.

RG, would it be too much to ask, for the ABC"s of pic for fx . also , a basic idiot setup. then a few of us could get the same setup
and help each other out?
      that would be very kind of you.
                   peace.,
                      - tom

Great idea!
My project site
Winner of Mar 2009 FX-X

troubledtom

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #12 on: February 12, 2006, 01:13:32 PM »
dsp too!!!???!!!?? :icon_twisted:
        - tom

donald stringer

Re: Wouldnt this be a better IC to base a sequencer on?
« Reply #13 on: February 12, 2006, 01:36:02 PM »
At radio shack you can buy an basic progamming kit for 79.00 for everything including instruction book. I am thinking of buying it.All though it will take a while to absorb it. I am willing to absorb that learning curve.
troublerat