[sdiy] The Okita Vocoder & others: which to make??? Quite a quandry...

[anthony]

This project looks very awesome (and familiar - I think I've seen something 
like it in a big collection of Japanese synth & guitar schematics, but not 
in the context of a magazine article like this...).

My 1st question is: What about that "optional stereo chorus board" that is 
shown in the drawing of the layout of the chassis innards, but does not seem 
to have a schematic or PCB diagram accompanying it elsewhere in the 
document. Wonder if it's similar to the one that the Korg VC-10 Vocoder has 
that uses two MN3004's?

My 2nd question is: If you one wanted to make these PC boards using 
something like Press-n-Peel Blue, wouldn't they need to reverse the image? I 
notice that the writing on the boards was legible the normal way, which is 
usually not the case for boards set up to use the relatively newer way of 
using PnP toner transfers. I didn't make a note of it, but this project may 
have been around when positive photoetching was in vogue and you had to 
either soak the schematic in oil or make a transparency of it before you 
could put it in your little UV light chamber to expose the photoresist, etc. 
etc...

One final comment: from all of the vocoder projects I have seen, it looks 
like they all have their merits: some being less complicated and great for a 
relative beginner to tackle and others, far more sophisticated have their 
merits too: like more options in the way the vocoder effects the sound. I 
think the first vocoder I make may either be this one - Okitasan's - 
although I am not at all jazzed about buying that many NE570's (or even 
using them in a circuit for that matter, but I think they're better suited 
in circuits like this here than in compander systems in BBD delay units...), 
or the Korg VC-10. The VC-10 is the only piece of gear I've ever wanted to 
make just exactly the way they did at the factory, right down to the 
balanced microphone jack and the gooseneck mic and the analog VU meter. I 
thought about making it sans keyboard, but then thought better of it. I'll 
have to use other BBD's than MN3004's, whether it be 2 strings of MN3006's 
or 2 MN3007's instead I haven't decided. The 2nd vocoder I make will more 
than likely be the Elektor one, but it will have to be redesigned to use 
LM13600's (NTE870's) because I don't feel like buying all of those CA3080's. 
I like the way you can patch it up in different ways like a synth module.

But all three I've spoken of here have their merits. Then there's the EMI (I 
think that's the name) vocoder. It looks like a worthwhile project too. I 
can't remember why I initially liked it and then panned it, but I'm sure it 
will come back to me. I reckon as the years pass, I will have made 4 or 5 
different vocoders. (More if people want to buy them from me... But that 
would be one of my own design, probably largely inspired by the Korg VC-10 
and using BL3207's if I make them in numbers to sell...)

Anyway, it is still possible that I may make the Okita Vocoder first. So 
that means I should plan on maybe setting up some sort of barter with 
someone who has a shitload of NE570's they want to get rid of. I have some 
vacuum tubes and other parts I could barter.

Cheers,
Anthony
----- Original Message ----- 
From: "HOSHUYAMA" <houshu at muj.biglobe.ne.jp>
To: "Andre Majorel" <aym-htnys at teaser.fr>
Cc: <synth-diy at dropmix.xs4all.nl>
Sent: Friday, June 20, 2008 11:34 PM
Subject: Re: Re: [sdiy] looking for diy vocoder options


> Hello Andre,
>
> Andre Majorel wrote:
>> I see there's a photo of an SVC-350 in the Okita Vocoder article.
>> Anyone knows enough Japanese to tell us what's the connection ?
>>
>>   http://rubidium.dyndns.org/cag/pdf/okita.pdf
>
> In the article, Okita says that he studied functionality of SVC-350,
> schematics of Roland VP-330, and user's manual of Moog Vocoder.
> Then, he realized the functionality using quite different components
> by his own design.
>
> Regards,
> Sam HOSHUYAMA
> Saitama, JAPAN
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