Feedback in FM synthesis

[Theo]

Thanks, intresting stuff.
Regards, Theo

----- Original Message ----- 
From: Don Tillman <don at till.com>
To: <t.hogers at home.nl>
Cc: <synth-diy at node12b53.a2000.nl>
Sent: Monday, August 07, 2000 4:52 PM
Subject: Re: Feedback in FM synthesis


>    From: "Theo" <t.hogers at home.nl>
>    Date: Mon, 7 Aug 2000 16:20:39 +0200
> 
>    From: Martin Czech <czech at Micronas.Com>
>    Sent: Monday, August 07, 2000 8:22 AM
>    > But: Yamaha operators do PM, this sounds different.
> 
>    Are you sure about this??
> 
> John Chowning's original patent is FM.  US patent 4,018,121:
> http://www.patents.ibm.com/details?pn=US04018121__
> 
> But the DX-7 patent is clearly PM.  US patent 4,554,857:
> http://www.patents.ibm.com/details?pn=US04554857__
> 
> I don't know why Yamaha choose to use PM instead of FM.  I would think
> that FM would generally sound warmer.
> 
>    When patching a VCO module as carrier the result is usually unlike
>    FM.  Not sure why this is, believe it is the inner working of the
>    VCO that makes it behave different.
> 
> For an analog VCO to sound like a DX-7 you would need very accurate
> tuning, linear frequency modulation, through-zero modulation, a sine
> output... and lots of aliasing and lookup table noise.  :-)
> 
>   -- Don
> 
> -- 
> Don Tillman
> Palo Alto, California, USA
> don at till.com
> http://www.till.com
>