emusonacid! legacy

Hi guys,

i have been spending a while trying to get familiar with and understanding the CORDS on the Emu Ultra 4. And i have been reading thru the manual and also some of the posts here in The Lab. It seems a vast topic but is very intersting and something i would like to try and learn about.

What i was trying to work out was how to have the LFO (which i would assign to the Modulation Wheel on my keyboard) controlling the WIDTH of a PULSE WAVE ?? So what you would call Pulse Width Modulatuion (PWM). Therefore i would be able to switch the PWM on/off (or control the AMOUNT) via the Mod Wheel on my keyboard ??

Thanks a lot if anyone can help ...............

Paul

Somewhere I described how to make PWM.
You need two cycles of a square waveform where the second cycle is inverted and the loop just covers one cycle.
With the cords you have to modulate the start position of the loop (SLOOP).

There is a trick to exactly move from one cycle to the other.

Thanks Rob,

i am not sure i will be able to work out how to set everything but i will try over the weekend thanks.

i could not find anything on PWM in the manual (unless its called something else). i see there are 4 x variants of a Pulse Wave, but you are saying to use 2 x cycles of a SQUARE wav (one Inverted) ??

On Page 276 in the manual (chapter on Cords/Mod Processors), it discusses the pathway of Pink Noise (Source) to Filter Cutoff (Destination) via a Lag Processor. However, it does not show the Cords screen for this example (though it does for all the other examples) and so i am not sure i have configured it correctly :-

Cord 1 = Pink Noise to Lag Processor

Cord 2 = Lag Processor to Filter Cutoff

It does not state what the Values for each of the parameters should be set to (and therefore i don't really have any reference as to what to overall effect should sound like !!).

And finally, there are TWO types of icon for the Lag Processor and so i am not at all sure what these should be set to in this configuration :-

Lag 1

Lag 1-in

Lag 0

Lag 0 -in

Why not try a clock to modulate filter cutoff.

I can't see why you would use a pink/white noise generator to modulate the filter.
These sources are best used to add a slight randomness to a destination.
I use them to turn a short burst of sampled and looped white noise into a subtly changing random sound to keep the sample from sounding looped by assigning the pink/white noise source to the pitch of the white noise sample.

Lag Definitions
Lag in = destination
Eg. Midi Clock division - Lag in

Lag = source.
eg. lag - filter cutoff

Consider the Lag processor as something to knock of sharp edges from a source
eg. it progressively curves a square wave as you increase the lag rate.

The Lag processor will have no effect until you change the rate of lag above 00 in the LFO page.

In the LFO page you are able to round of the square shape of the midi clock by adjusting the lag rate.
This is useful to turn a square clock division into a smooth tempo locked sinoid LFO type modulation.

These tempo synced LFO type cords are great for modulating ...
Amp vol
Pan
Pitch
Resonance
And filter cutoff

The results are very musical when set up correctly and used in combination with one another they can produce some great tempo synced effects.

I use them to turn a short burst of sampled and looped white noise into a subtly changing random sound to keep the sample from sounding looped by assigning the pink/white noise source to the pitch of the white noise sample.
You mean so it constantly sounds like the sound is changing ?

It adds a random variation to the pitch and therefor the frequency, this stops the short looped sample of white noise (which is made up of random frequency content) from sounding like a loop.
If the loop is short and no variation occurs your brain will detect the loop within a few cycles.
So this method reduces the need for a long loop cycle on a white noise sample.

Consider the Lag processor as something to knock of sharp edges from a source
eg. it progressively curves a square wave as you increase the lag rate.
You mean it rounds off the effect of the source to make its effect (on the Desitination) more subtle ?

Not really more subtle.
Think of it as behaving as a pot/slider would alter a sound rather than the on/off switch behaviour of the unmodified input.

Consider the square LFO waveform or a clock input as the switch being modified.
It takes the stepped values of this input waveform and progressively turns it into a sine so the value sweeps from max to min instead of jumping max to min.

If the lag value is set too low/high the effect will not be correct, this value has to be set by ear in the LFO/lag page.