[sdiy] 32 Stages of Vactrol Phase Shift

[scottnoanh at peoplepc.com]

Hi Pete,

I think the picture makes it look worse than it really is =0)  It's a lot of
repetition, mostly - identical stages one after the other.  A phase shifter
is nice because it's unity gain, and you can tap from any stage to get
whatever sound you want.  Because the stages are identical, the tap points
are identical, so you can hardly miss.

As far as breadboarding in general, if I'm working off of a schematic, I
make a copy of the schematic and methodically trace through every connection
with a highlighter as I make them (I do the same thing when building on
protoboard).  Does everything work when I'm done?  Not bloody often - but
it's usually really easy to spot the mistake once going through the process.
In the case of this circuit, once you've built four stages, building the
next four stages is exactly the same.  Then the next four, then the....well,
you get the picture. =-D

Usually, also, there's the divide and conquer approach - identify and break
the circuit up into subsections, and put those in one by one.  When done
with a section, stop and test it to see if it's working as expected, then
move on to the next section.  Hard to do in some cases, but usually quite
doable.

Another thing that helps is I *try* to color code the wire.  My main rule
is, for the power and ground connections, *always* use the same color of
wire (red) for +V, a different color of wire for -V (black), and another
color for ground (green) - and *never* deviate from that.  After that, I
play a little bit more loosely, but generally I'll use yellow for CV, white
for input, blue for output, sort of along those lines - it just helps
spotting things a little easier.  I often stray on those, but _never_ for
the supply lines.  If I need to make a ground connection and have to search
an hour for that bit of green wire (exaggeration) I'll take that hour.  I
have my reasons ;-)

Take care,
Scott


----- Original Message -----
From: "Pete" <23isgood at gmail.com>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Saturday, April 15, 2006 6:18 PM
Subject: Re: [sdiy] 32 Stages of Vactrol Phase Shift


OMG! How can you possibly keep track of all those wires? That looks so
complicated. Every time I breadboard something I get lost in the mess of
wires and stuff. Sometimes the circuits work, but mostly they don't work. I
spend too much time backtracking everything trying to find the problems, and
then eventually get it working only half assed. I have no idea how you can
get this thing working with all that complexity. I need to improve my
breadboard technique. By the way that hypertriangular wave sounds very
unique.

pete