Virus C question
 

Hey all!

I have a potential n00b question for you...

Spurred on by the other thread regarding that PPK sine wave w/delay, I decided that instead of just saying "thats an easy sound to program", I would actually give it a go.

Anyways, I started with an INIT patch, and noticed that the sound seems to oscillate/modulate by itself, but cant figure out why. I've looked at the DCO and there is no function to dial in the mod, I've also looked at the filter, and amp, and cant seem to figure out why the init patch is kinda self-oscillating. Is this normal???

It doesnt happen on my other synths (Yamaha CS-10 and Juno-60)

It's probably obvious, but I just cant suss it out...

Cheers!

Jase

Edit: OK, to be a bit more precise, it sounds like either the Amp is being Modulated by an LFO, or something like that, but the LFO's arent routed to any destination, and I've turned them off, and it is still oscillating

Isn't it modulation of the pulse width?


Drammy

I'll have to check that out! Cheers Drammy...

P.S is there any way to turn it off?

With the INIT patch, aren't both oscillators used?

They're each freely running (ie. not forced to sync' as standard), so you'll have slight phasing differences when they're mixed together.
They may also be emulating the unstable/varying pitches of their analogue predecessors. It's like they're very subtly detuned. This is the "modulation" you'll hear. I think there is an option somewhere to turn off this emulated instability of the oscillators.

Yeah - I think Timo's right. I don't think pulse width modulation is standard in the INIT patch...

Yeh - definately right there timo - two oscs - subtly detuned, so the modulation arises from phase cancellation.

It?s because osc 2 in the init patch has a detune value of 32 by defualt...

You guys are legends!!!!

Sheesh, makes me realise that I am still a novice as far as programming my Virus, and general knowledge of synthesis...

If only I had more time....

Jase

:)

Damn straight, Jase.

There are some seriously knowledgable peeps (people) on this board.

Thank you all for sharing your knowledge!

Just athougt, also check out the PHASE INIT that sets the starting point in the osc cycle, in case it is OFF, they will oscillate freely and will sound like their amp is slightly modulated