[sdiy] Re: [AH] cloning a PPG EVU / Wave?

[Tom Wiltshire]

Todd,

Building an 8-voice polyphonic synth of any type is a major task.  
That said, the PPG Wave has to be a reasonable target.

As you mention, the resolution and memory requirements are low, so  
that makes life easier. I'd have thought that you could use the  
oscillator design from Paul Maddox's Monowave or design something  
similar.

For an SSM filter, you're probably looking at SSM2044's, which are  
the only ones that seem to still be available in any quantity. This  
chip has a good pedigree for digital/analog hybrid instruments,  
having been used in the Emu Emulator. For a one-off, you might be  
able to find a few of something else.

For VCAs, I'd have thought you've got a wider choice. Personally I  
doubt there is much audible difference between VCAs once they reach a  
certain level of quality. Obviously some designs have faults that  
have become distinctive features, but I doubt CEMs are in that category.

So in summary; difficult, but possible.

Tom


On 10 Aug 2007, at 18:40, Todd Sines wrote:

> if the software was re-written to allow for CC control from the OS  
> level -- [apparently later versions had updated MIDI and were  
> responsive enough to be controlled via MIDI]
>
> a software based editor would need to be sending CC's and not just  
> sysex manipulation [usually slower, or aliased I thought]
>
> wavetable aliasing is good, but VCF aliasing is not so good.
>
> would it make sense to build upon the Motorola 6809 processor?
>
> I think the characteristics that people enjoy about the PPGs are
> early D/As with 8-12 bit wavetables versus cleaner 16-bit wavetables
> SSM VCFs
> CEM VCAs
>
> so either using the exact parts or rebuilds of them are probably  
> required to make it still sound the same..
>
> From what I gather the Monowave wouldn't be quite the same [doesn't  
> mean I don't want one though]
>
>
> +odd
> --
> On Aug 10, 2007, at 1:30 PM, Werner Schönenberger wrote:
>
>> Hi Todd,
>>
>> just some comments,
>> - the EVU only makes sense in combination with a Wave/WaveTerm  
>> since the controlling via MIDI-CC is very limited
>> - the EVU technically more or less is the same as a Wave 2.3  
>> without the user interface but with the difference that at the EVU  
>> each voice can be placed in the stereo position and has its own  
>> volume pot.
>> - The Monowave is a monophonic synthesizer and due to its  
>> different technical development it might sound different (but very  
>> well as far as I heard)
>>
>> Cheers,
>> Werner
>>
>> Am 10.08.2007 um 16:50 schrieb Todd Sines:
>>
>>> Juergen, at all..
>>>
>>> Has anyone attempted this?
>>>
>>> I just lost out on a fierce bidding war on eBay for Tom M's PPG  
>>> EVU [it went for $2858] and am thinking there are other ways  
>>> around this..
>>>
>>> I'm more interested in editing on the rack vs. software / MIDI  
>>> controllers but either way would work..
>>> The racked PPG Wave is what I'm after.. but the 8 voice aspect of  
>>> the EVU could be cool.
>>>
>>> http://www.seib.synth.net/images/fischbach2.jpg
>>> http://www.seib.synth.net/ppg/mods.htm
>>>
>>> http://www.ppg.synth.net/
>>> http://www.antarcticamedia.com/ppg/evu.htm
>>> http://www.synthmuseum.com/ppg/ppgevu01.html
>>> http://www.waveterm.com/
>>>
>>> I know some people in NYC to get started on this with, but I have  
>>> a feeling this could [may need to] be a group project.
>>>
>>> or.. does a Monowave [in kit form or otherwise] really match up  
>>> to the PPG's sound?
>>>
>>>
>>>
>>> +odd
>>>
>>
>>
>>
>
>
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