[sdiy] Newbie alert :-)

[Scott Gravenhorst]

Nicolai Czempin <nicolai.czempin at alcatel.de> wrote:
>Grumble... I had written a long account of my recent minmal success, and 
>managed to kill it. I guess I'm just not cut out for all that hi-tech 
>stuff ;-)
>
>Rather than typing it all up, here's the short version:
>1) I managed to complete a simple 741-based oscillator (non-VC), and, 
>yes, an oscilloscope is essential. It also helps to remember how to 
>connect -V on the 741...
>2) I'll spare you with details of my (current and future) experiences on 
>the ML, but I'll put such things in my weblog.
>3) What do you people use to generate e. g. gifs of schematics to put up 
>on webpages?

Believe it or not, I use PaintBrush.  I have a file that serves as a template
for symbols such as transistors, diodes, resistors, gates, opamps, etc.  I
copy and paste those into a blank document.

>4) I'll first build a non-modular synth, but a simple one with just a 
>keyboard (so you do need the VCO), with filter and envelope using simple 
>knobs rather than being voltage-controlled.

Had you considered a kit?  Such as the FatMan?  There are others as well. 
More FatMan info at:

http://home1.gte.net/res0658s/fatman/index.htm


>5) What do people use for a keyboard? I'll get a MIDI/CV interface 
>eventually (I have a P-60 and a PSR-290) but I'd like to hack some cheap 
>plastic toy to get started. 3 octaves, or even just 1, would be 
>sufficient for the moment. The cheapest thing I've found so far (without 
>really looking) is some instrument that has a tube you blow into and you 
>can play on the keyboard. Costs 20 Euros. Anything cheaper?
>6) For some strange irrational reason the site http://home.swipnet.se/ 
>is blocked by the company firewall ("rated as pornography"), so I have 
>to wait until I finally get my ADSL connection at home before taking a look.
>7) Those schematics mentioned look very interesting, but I'm looking for 
>something even simpler than that, possibly at the cost of lower quality. 
>If only for being able to have some kind of baseline. If I start with 
>the "good stuff", I won't know in what respect it's better than the 
>"baseline". So, here's a challenge: Design the simplest VCO that could 
>possibly work! At the moment I'm planning my next step to be one with 
>two op-amps, 3 resistors, 1 capacitor and a diode.

I think that René Schmitz's VCO (4069), at the URL I posted is about as
simple as it gets.  But don't be fooled by it's simplicity, it's quite
musically useful and not a "crap" circuit.  I got 9 octaves from it, others
have gotten more.

>mfg Nicolai
>

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-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
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