[sdiy] Elektor Formant synth build

[Terje Winther]

Hi,
I have built the complete Formant modular ("standard 12 module  
combination") not too long ago (from some NOS boards and front panels  
I came across).
As some have said already: there are some parts that are difficult and/ 
or expensive to get hold of today. Some of them could easily be  
changed into newer parts, as I did; other parts are essential for the  
proper operation of a module, so you need to get hold of the correct  
part. I was able to get some old NOS parts, so I was able to build it  
mostly like it is described in the book.

As for building: for me it was much more work than modern modular DIY  
synths, because you need to select parts in a much more specific way  
then on modern modulars. For several of the modules I needed to build  
small test-circuits on veroboard so I could select correct  
transistors, diodes and ICs, and for some of the modules it is a  
fairly specific way of adjusting the trimmers or even finding the  
correct value of a resistor, involving desoldering parts, shorting out  
components and connections and the like. Quite doable, of course, and  
everything is very well explained in the book, so even though it is a  
little more work than on contemporary DIY modulars (which are easier  
to build and works pretty much straight away), it is mostly fairly  
easy to build these modules. The original PCBs are very spacious  
(probably because it was intended for old components that tended to be  
physically bigger thans parts today), so sometimes it feels that there  
is too much room between components. Makes it very easy to put in  
components and solder them.

Another interesting aspect is that the book recommends certain  
preconfigured connections on the rear of the modules (where the power  
is supported to the modules, making this modular a semi-modular (much  
in the same vein as the ARP 2600), and combined with the fact that  
much of the volume/amount pots are on the outputs of the modules (and  
not on inputs as is standard today), makes for some different  
approaches when using the modular.

Quite an interesting sound to it all, too. Sort of more mellow, more  
creamy and due to the fact that the sound always travels through two  
different filers and the resonant filters (unless you bypass by  
patching), it always sounds more "acoustic" than raw electronic. I  
used the recommended minijacks for the front panels, so it interfaces  
easily with other types of gear.

You do need a good measuring tool when building these modules, and you  
do need an oscilloscoop as well.

The books are a good read, and recommended for everyone into building  
synth modules, because of the was things are explained. The Formant  
modular is old, though, so as other have said: you might want to  
consider more contemporary DIY modulars. Quite a lot to choose from  
today.


Terje

Den 8. nov.. 2015 kl. 14.02 skrev josh wilkinson:

>
> Hello All,
>
> My name is Josh Wilkinson, i am part of a Hackerspace in Brisbane  
> Australia.
>
> Myself and a group of electronics enthusiasts (ranging form  
> electricians to programmers to mechatronics) are keen to build the  
> Elektor Formant synth.
> We have been reading book 1that was published with all the  
> schematics and notes in it.
> Has anyone had any experience building this synth?
>
> Our main priority obviously is generating a proper PCB file that we  
> can replicate for the modules. Has anyone already converted the PCB  
> schematics in the book to Gerber files?
> If anyone has and feels like sharing that would be incredibly helpful.
>
> Also any leads on tracking down the tricky Fairchild chips?
>
> Really any experience with this build would be appreciated.
>
> Cheers,
> Josh and HSBNE Crew.
> Sent from my iPhone
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
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Terje Winther
terje.winther at wintherstormer.no
http://wintherstormer.no/





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