The initial idea for the Event Timer came to me from a Reaktor module of the same basic function which I found to be extraordinarily useful.


Have you ever paced an event to begin AFTER another one begins? One way of doing this is using a pulse delay. This will work pretty well until the duration of the original event is modified. Because the delays can't track the original, eac modification will require a reconfiguration of the preset delay time Fine if you're working with single events - but if the event your delaying is time variable, you're in for some heady readjustments.

The Event Timer ends all this set-up with a single pot setting and will track its reference signal perfectly at any speed. The two are permanently linked and not time dependant -- this device senses and responds to the amplitude of it's input against a pot variable level threshold setting. Each of the three independent comparators have a manually adjustable trigger threshold. At this point, the delays you dial-up are locked to the original and will track it's host even if the duration of the original event is modified

There is a twist to this circuit however that even the Reaktor device didn't do - not only does each comparator have it's own Q and Q not outputs, but each can run independently as separate comparators OR be linked together serially (the threshold of comparator 2 is linked to that of comparator 1, the threshold of 3 is linked to that of 2).

In this mode, all combined comparators are linked to input 1. While comparator 1 will have a free range (can be set to any reference level), the threshold level of subsequent comparators down the line can't be adjusted lower than the the one preceding it as they use each others pot reference as their lower limit - much like a parametric EQ or fixed filter bank. In this way, you can extrapolate two or three different voltage levels from one signal --> one taking the lower) range, one taking the mid and one taking higher range of the same input.

Each comparator's link function is switch selectable. You can link 1 and 2 and keep number three fully independent with its own input it you care to

A unique feature to the Plan B M17 are two summed Q and Q not outputs which sum the logical outputs from all three comparators whether they are slaved together or run independently. To provide for a more useful summing function, all comparator 'true' (high) levels are converted to momentary 3ms pulses at these summed outputs.

In application, picture the attack phase of an envelope generator (see diagram 1 below). If you put that EGs output into this module and set it in combination (serial) mode, you could get a high out when it's halfway to full voltage (mid attack) and another when it reaches it's full amplitude (full attack). In this way, you could trigger other envelopes during the cycle of the first that would track regardless of the overall length of the envelope.

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Audio Sample 1 click here

This first audio sample gives a clear indication of the Event Timer's operation. It's three events that are timed together by the decay of the first sound. You'll hear how the track each other then the decay of the first eg is shortened. I'm using the Q NOT outputs on this patch. The audio path of this patch consists of a single Model 15 VCO through the lowpass out of the Model 12 Vactrol Filter.

Audio Sample 2 click here

This is a simple patch that's being mated through a VCA with a long attack envelope (call this EG 1). and have the linked two other ADSRs to EG 1 using the Event Timer that control pan and timbre. The first comparator is triggering an ADSR that opens a filter, the second comparator's ADSR pans the sound. The distinct difference between this and using a sequencer or gate delay it that all three ADSRs stay high as long as EG1 does, regarless of how fast the overall event lasts (notice that all three parameters (AMPLITUDE, TIMBRE and PAN) fade together at the end, yet are cascaded at the beginning. I'm using the Q outputs on this patch.

This configuration produces an interesting pan algorythim that's synced to the overall amplitude of the event itself. Notice the sound fades in on the LEFT channel initailly, then quickly pans to the RIGHT before coming to rest at the CENTER for a sustained period, then pans back to LEFT as the overall amplitude drops. Note that ths pattern stays intact even when the overall time of EG 1 is altered dramatically. A picture being worth a thousand words, the diagram below illustrates what's happening and how the Event Timer makes it happen. The numbers corrospond the M17's set threshold levels:

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New audio Samples - Rhythm King..

The following samples are an example of the many rhythmical patterns that can be generated with the Event Timer. What you're hearing is an all-Plan B patch, sans an Envelope Generator (thanks to the swell ringing of the Model 13, a pulse wave by itself can serve as a short decay-only EG!). Two Model 15's, both sine, the output of one used to FM the other, going into a Model 13 Dual Timbral gate, with it's frequency controlled by a random pattern set up on the Model 21 Milton Prototype and the envelopes set by the Model 17 from a RAMP WAVE received by a third Model 15 VCO...and there lies the 'trick'.

The Model 17 is receiving a low-frequency ramp wave as it's sole input. Set to SLAVE mode and coming out the A+B+C sum output, the ratio of the first and second pulses can be adjusted, resulting in some interesting syncopations. The sum output of the Model 17 is generating tow pulses, one when the ramp begins and the other delayed by the threshold setting of it's second comparator. Have a listen:

Sample 1 (second event set to a dotted 32nd note)
Sample 2 (second event set to a syncopated 8th)
Sample 3 (first event set to a 32nd note)
Sample 4 (first event set to 8th syncopation)
Sample 5 (both event s set to equal 8ths)

Note: the frequency of the LFO ramp is identical in all samples -only the comparator 2 setting has changed in each. This could be done by a standard Gate Delay..if the pace remained constant through the phrase. The difference - the Model 17 will stay in horizontal sync (rhythm intact) with accelerando (increase of pace) and retards (decrease in pacer) - this you can't do with a no Gate Delay!

Model 25/17 demos by Thighpaulsandra with Peter Forrest shot at Aeriel Studios