Re: [AH] totally insane!! system 700 sequencer

From James Husted
Sent Fri, Jul 11th 2008, 22:43

Another way is to use a clock that also provides a sawtooth and use a  
level detector/comparator circuit to compare against the knob row to  
make the gate as long as the value reached by the sawtooth wave =  
variable gate.
-James

On Jul 11, 2008, at 10:14 AM, David Moylan wrote:


> Sounds like you need a voltage controlled one-shot.  Probably easy  
> enough to build with a 555 timer.  Any manufacturers have such a  
> thing out there?
>
> Dave
>
> James Husted wrote:
>
>> What I would find more useful is to have a variable gate time for  
>> each step instead (or along with) the variable step time. To be  
>> able to adjust the step's note length within the step (and not  
>> changing the total sequence time) would be a very useful thing to me.
>> -James
>> On Jul 11, 2008, at 9:28 AM, alt-mode wrote:
>>
>>> Ah OK, that's what I thought you meant.  Of course, the main  
>>> feature of the
>>> System 700 sequencer in this respect is rotary switches that can  
>>> change the
>>> timing accurately on the fly.  A switch and a pulse divider might  
>>> be easier
>>> to work with.  This would also be true for the comparison to the  
>>> SAM-16
>>> sequencer that Gene mentioned; switching from 1/8th to 1/16th  
>>> quickly and
>>> accurately is tough with a continuous knob.
>>>
>>> I guess no single step sequencer will ever have all of the  
>>> features possible
>>> but it is cool that each seem to have their own quirks and  
>>> personality that
>>> make them unique!
>>>
>>>     Eric
>>>
>>> On 7/11/08 11:13 AM, "charles graef"  
>>> <redacted@example.com> wrote:
>>>
>>>
>>>> Yup -- sorry, I phrased it badly.  When you clock from an  
>>>> external VCLFO you
>>>> can modulate the frequency of said VCLFO with the CV out from  
>>>> one of the
>>>> sequencer rows and thus modulate the duration of any given  
>>>> step.  For
>>>> example, in theory if the CVs in the row were
>>>>
>>>> 0v | 1v | 1v | 0v | 1v | 1v | 0v | 1v | 1v | 0v | 1v | 1v
>>>>
>>>> the rhtymn of the output would be
>>>>
>>>> 1/4 | 1/8 | 1/8 | 1/4 | 1/8 | 1/8 | 1/4 | 1/8 | 1/8 | 1/4 | 1/8  
>>>> | 1/8.
>>>>
>>>> An octave is a doubling of frequency and you're working 1v/oct.   
>>>> If the
>>>> clock goes twice as fast, the duration of the step is 1/2 as  
>>>> long.  Etc.
>>>>
>>>> --Chuck
>>>>
>>>>
>>>> -----Original Message-----
>>>> From: alt-mode [mailto:ah@alt-mode.com]
>>>> Sent: Friday, July 11, 2008 10:11 AM
>>>> To: charles graef; 'analogue'
>>>> Subject: Re: [AH] totally insane!! system 700 sequencer
>>>>
>>>> On 7/11/08 9:39 AM, "charles graef"  
>>>> <redacted@example.com> wrote:
>>>>
>>>>
>>>>> The Doepfer sequencer allows the CV or audio input to  
>>>>> individual steps.
>>>>>
>>>> The
>>>>
>>>>> Analogue Systems sequencer has skip.  Would be nice if every  
>>>>> sequencer had
>>>>> everything.
>>>>>
>>>>>
>>>> Very true!
>>>>
>>>>
>>>>> Re the Roland, I should think it would be possible when using  
>>>>> an external
>>>>>
>>>> VC
>>>>
>>>>> clock with a row of sequencer CV and thereby halve a given step  
>>>>> duration
>>>>> with an octave increase in CV from that row, quarter the  
>>>>> duration with a
>>>>> 2-octave increase, etc.
>>>>>
>>>>
>>>> OK, I don't think I parsed that.  Are you saying that you can  
>>>> use the CVs
>>>> from a row to modulate the clock rate and thereby achieve the  
>>>> timing changes
>>>> that are possible with the per step switches?  Please elaborate.
>>>>
>>>>     Eric
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>
>