[sdiy] Prophet 08 sub oscillator mod?

[cheater cheater]

Wow, synth porn.
At least you know how your enemy looks from the inside... or something.

Tim:
>Adding the hardware to create sub-octaves: big job
What are you basing this on? Is there a schematic you are following?
What would be involved?
>Reverse engineering and reprogramming the operating system and adding the
>hardware to allow control of the suboctaves: HUGE job.
Oh yes, definitely.
But on the other hand, we're talking about a simple uC program here.
This isn't a supercomputer. People have reverse engineered bigger
things; the problem is that ASM isn't as popular nowadays, so if you
run into trouble, you might be hard pressed to find someone who knows
what to do :)

Cheers
D.

On Sat, Jan 3, 2009 at 11:47 AM, Tom Wiltshire <tom at electricdruid.net> wrote:
> Here's some internal photos of the Prophet if you want to know what you're
> up against.
>
> http://prophet08.com/prophet08/
>
> T.
>
>
> On 2 Jan 2009, at 23:46, cheater cheater wrote:
>
>> yes that's a big caveat that you can't controll it from the uC.
>> but microcontrollers can be reprogrammed right? :))
>>
>> On Fri, Jan 2, 2009 at 9:39 PM, Scott Nordlund <gsn10 at hotmail.com> wrote:
>>>
>>> It's probably doable if you don't mind surface mount soldering and
>>> finding some place to mount an extra little board.  Assuming the Prophet 08
>>> works more or less like any other analog-ish synth (in that the individual
>>> oscillator signals are accessible somewhere), it's just a matter of adding a
>>> flip flop for each oscillator.  You could easily cascade these for more
>>> sub-octaves, and use enable or reset pins to switch it on and off.  You've
>>> also got to work out the signal levels, buffering, mixing, etc.  Since no
>>> one (to my knowledge) has done any Prophet 08 modifications or posted
>>> schematics, you'll just have to go at it with an oscilloscope and figure it
>>> out yourself (shouldn't be too difficult).  It will take a fair amount of
>>> hardware though (8 dual flip flops and 4 quad op amps?) since you're dealing
>>> with 16 oscillators.
>>>
>>> There's a disadvantage, though, in that the sub oscillator won't be
>>> programmable at all from the Prophet 08 interface, it will be on/off only
>>> and independent of the main oscillator level (unless you want to add a bunch
>>> of VCAs), and it won't be tied at all to any other features (modulation,
>>> etc.)
>>>
>>> ----------------------------------------
>>>>
>>>> Date: Fri, 2 Jan 2009 18:53:02 +0000
>>>> From: cheater00 at gmail.com
>>>> To: synth-diy at dropmix.xs4all.nl
>>>> Subject: [sdiy] Prophet 08 sub oscillator mod?
>>>>
>>>> Hi guys
>>>> Since the Mopho has the two sub-oscillators, and the Prophet 08
>>>> doesn't, I bet more people than me have wished it did! So, has anyone
>>>> considered such a mod? Even if it wouldn't be stored in the patch etc.
>>>>
>>>> Is anyone familiar with the new prophet's guts, and if so - would that
>>>> be a difficult task to add a Mopho style sub?
>>>>
>>>> I don't even know if the insides are canned or if they're moddable.
>>>> Has anyone got pics of the insides? I tried googling, but came up with
>>>> nothing :)
>>>>
>>>> Cheers
>>>> D.
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