[sdiy] Duh. Major sequencer tuning, realization. :O

[Rykhaard D.A.M.I.A.N.]

On 1/7/06, Dave Kendall <davekendall at ntlworld.com> wrote:
>
> Hi
>
> >I'm just now, trying to figure out how to get the entire tuning system
> built,
> >so that I have +1 and +2 octave switches available, for each of the steps
> in
> >the sequencer, as well.
>
> I might have missed the point, but do you really need the top C?
> Why not have the 12 position rotary go from say C to the B above it, and
> use
> octave switches to flip the range up or down.
> I think a 13 pos. switch is going to be quite hard to find.....
>
> Dave


Sorry about that Dave. :O  I tend to speak in riddles and disconnection, too
often. :O :(  Trying to fix that. :)

Before I had realized my error - winding the resistors around the 12
position rotary switch, I thought I could be happy - with C1 to C2, as that
would give me an octave, there.  I could then tune the oscillator to the
required pitch basis and continue on happily. ;)

Now that the error has been realized though ....... :)

Yes - as you'd typed, is the current plan, mostly.  The toggle switches for
Octave will be listed either:

+1 octave / Off
+2 octaves / Off

or

+1 octave / Off / -1 octave

It depends on how many of which type of toggle switches, that I have in
stock at the moment. :)  (I'll require 4 sets.  1 set for each of the 4
steps.)

Hopefully - I'll be able to convert 1 of my 3 pole 4 position or 4 pole 3
position switches, to a 1 pole 12 position switch, for overall
transposition. :)

I forgot to add a portamento function to my PC board as well.  I'm going to
see if I can fudge one of those in today as well, rather than building a
daughter PCB for the panel. :)

Off to experimenting and figuring out, what I'd been doing wrong. :O

I'm still trying to figure out why, with a standard ring of 12 x 121 ohm 1%
resistors around a 12 position rotary, my tuning on it goes:

1 - C
2 - C#
3 - D
4 - D#
5 - E
6 - F
7 - G (instead of F#)
8 - A (instead of G)
9 - C (instead of G#)
10 - unmeasured
11 - unmeasured
12 - unmeasured

...... notice the exponential rise in pitch, around the resistor string??
:( :(  I can't figure THAT out. :(  I'm going to move to the next rotary
switch step, thinking that the rotary that I've rebuilt for proper tuning,
may have a bad connection on 1 of the steps, decreasing the resistance, or
something. :(

Once these bugs are worked out - I'll finally be posting the schematic for
the thing, as it then exists.  :)

--
Take care,
Warmth and Peace,
Ryk

http://deathlehem.bravehost.com/damian.html - D.A.M.I.A.N.;s webpage - Jan.
0406 update
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