[sdiy] Craig Anderton's Multiple Identity Filter

[Andrew Simper]

Ahh, thanks Brian, that makes much more sense! I haven't run across
the Matrix-12, only the Xpander, the later of which is presumably half
a Matrix-12 seeing as though it has 3 zones and 6 voices and the
Matrix-12 has 6 zones and 12 voices.

Cheers,

Andy

On 27 October 2016 at 13:36,  <rsdio at audiobanshee.com> wrote:
> Hi Andrew,
>
> You gotta say which "Matrix" you're talking about. The Oberheim Matrix-12 is two Xpander voice boards in a keyboard. The Matrix-12 has the exact same filter features as the Xpander because the whole voice architecture is the same. The only difference is that the Matrix-12 has twice as many voices, and twice as many Zones.
>
> (Strangely, the Xpander only has 3 Zones, making it a little more difficult to do multi-timbral analog from a MIDI guitar, whereas the Matrix-12 has 6 Zones. Then again, I think you can still assign one string to each voice.)
>
> You're probably thinking of the Oberheim Matrix 6 keyboard and Matrix 1000 rack, which are very crippled compared to the Matrix-12 and Xpander.
>
> Brian
>
>
> On Oct 26, 2016, at 6:57 PM, Andrew Simper <andy at cytomic.com> wrote:
>>
>> Hi David,
>>
>> As far as I remember the Oberheim Matrix only had a fixed 4 pole
>> cascade type low pass filter, did you mean the Oberheim Xpander? If so
>> then yes this is the easier way to generate different responses by
>> taking weighted sums of the output of each stage, but you don't get
>> the "correct" responeses, you get sags above the cutoff in the band
>> pass and high pass modes, and amplitude attenuation below cutoff with
>> changing resonance in all modes, which kind of sounds like changing
>> the cutoff upwards with increasing resonance in band pass and high
>> pass modes, but the resonant peak stays put.
>>
>> Cheers,
>>
>> Andrew
>>
>> On 27 October 2016 at 03:23, David G Dixon <dixon at mail.ubc.ca> wrote:
>>> I've got a filter design called the "Polaris" that gives nearly 30 different
>>> useful filter modes in a much simpler say than the MIF, and doesn't need a
>>> Curtis chip to do it.  Intellijel sells it for $229.  If you want to check
>>> it out, go here: https://intellijel.com/eurorack-modules/polaris/  It's
>>> based on a Roland-esque cascaded-stage four-pole filter, and takes
>>> inspiration from Grant Richter's old Oberheim Matrix multimode filter
>>> design, but it goes a fair bit further than that.  The mode switching is
>>> done with a microcontroller generating a 17-bit code which controls five
>>> analog switches, which I still don't know how to do, so I don't have a
>>> handmade version of it yet.
>>>
>>>> -----Original Message-----
>>>> From: Synth-diy [mailto:synth-diy-bounces at dropmix.xs4all.nl]
>>>> On Behalf Of KA4HJH
>>>> Sent: Wednesday, October 26, 2016 8:55 AM
>>>> To: sdiy
>>>> Subject: Re: [sdiy] Craig Anderton's Multiple Identity Filter
>>>>
>>>>> On Oct 26, 2016, at 4:37 AM, Andrew Simper <andy at cytomic.com> wrote:
>>>>>
>>>>> From what I can see with Craig Anderton's filter it won't actually
>>>>> give the "correct" responses for all the different filter types unless
>>>>> there is a way to switch the polarity of the resonance, and also where
>>>>> the resonance is added. Am I missing something? Sorry if I've posted
>>>>> all this stuff before.
>>>>
>>>> This is one of the reasons I reposted the link. I remember
>>>> some discussion about this and wondered how Craig's design compared.
>>>>
>>>>
>>>>> On Oct 26, 2016, at 12:30 AM, Doug Terrebonne
>>>> <dougt55 at yahoo.com> wrote:
>>>>>
>>>>> The MIF article has been on synthdiy.com for a long time -
>>>>> http://www.synthdiy.com/files/2002/MIF.pdf
>>>>
>>>> I didn't even know it was there.
>>>>
>>>>
>>>>> On Oct 26, 2016, at 5:43 AM, Roman Sowa <modular at go2.pl> wrote:
>>>>>
>>>>> Why use predatory file hosting sites while there are sites
>>>> like synthdiy.com or synth.net, which AFAIK are managed by
>>>> this list members.
>>>>
>>>> I completely forgot they existed but then this is the first
>>>> time I've received a complaint about Mediafire.
>>>>
>>>>
>>>>> On Oct 26, 2016, at 5:43 AM, Roman Sowa <modular at go2.pl> wrote:
>>>>>
>>>>> Why use predatory file hosting sites while there are sites
>>>> like synthdiy.com or synth.net, which AFAIK are managed by
>>>> this list members.
>>>>>
>>>>> If anyone's interested I can also host any doc files (no
>>>> audio/video/warez or any pirated stuff) at regular downolad
>>>> links, no ads, no download buttons or popups.
>>>>
>>>>
>>>> Good to know. I may take you up on it.
>>>>
>>>>
>>>> Terry Bowman, KA4HJH
>>>> "The Mac Doctor"
>>