MOTM

Hi Gozer,

Welcome and congrats on your MOTM-650 purchase!

1 - I'm pretty sure there isn't a transpose feature in the MOTM-650,
although I haven't looked for one so I may have missed it. My MIDI keyboard
is 6 octaves and has an octave switch so I haven't needed it really,
although partial octave transposition might be nice. 

2 - No, the MOTM-650 is probably putting out the correct voltages and you'll
need to calibrate your oscillators to it. I purchased all of my MOTM-300 and
MOTM-310 oscillators used and they were all calibrated a little differently
so I had to spend some quality time with them to get them calibrated the
same. I think I may need to go back again and tweak them a ghost-hair more
but they stay reasonably in tune together over a 6 octave range so I'm not
really concerned! ;-)  I'm sure someone on the Synthesizers.com list will
know how to calibrate the Q106.

Just yesterday my used Fluke 8840A multi-meter arrived in the mail so I
thought it would be good to try it out on the MOTM-650 to see what kind of
readings I would get. This meter has 5 1/2 digit precision so it can display
very tiny variations in voltage etc.  I had my MOTM-650 in "Poly 2 ST" mode
so I checked voltages at each octave for each channel:

Voltage Readings:
Channel 1	Channel 2	Channel 3	Channel 4
0.0027	0.0030	0.0030	0.0047
1.0032	1.0036	1.0033	1.0047
2.0036	2.0041	2.0036	2.0047
3.0043	3.0048	3.0040	3.0049
4.0051	4.0056	4.0045	4.0051
5.0058	5.0064	5.0050	5.0052
6.0070	6.0075	6.0057	6.0054

Voltage Difference Between First And Last Octaves:
Channel 1	Channel 2	Channel 3	Channel 4
0.0043	0.0045	0.0027	0.0007

Largest Average Variances (averaging readings per channel and then taking
the difference of the lowest and highest values):
Channel 1	Channel 2	Channel 3	Channel 4
-0.0018	-0.0020	-0.0011	-0.0003
+0.0025	+0.0025	+0.0016	+0.0004

So while there is some variance (although channel 4 is almost perfect!) we
are talking about mere THOUSANDTHS of volts which I would think in almost
all cases would be inaudible when listening to your oscillators. If you
divide 1 volt by 12 it's about 0.8333 volts (0.8333 volts per half step).
So, dividing a single half step by my 'worst' amount of variance between 7
octaves (channel 2 at 0.0045 volts) you'd have over 18 different micro tonal
'notes' within each half step! ((1 / 12) / 0.0045) = 18.5185   That's about
216 notes per octave!!!! I doubt I could tell any difference in a shift that
tiny!  

And it should be noted that the MOTM-650 I have here was purchased from Neil
Bradley who was involved in writing the original program code so I'm
assuming that this is either one of the first off the assembly line or
possibly a late beta so there may have been minor tweaks and improvements
since then.


Best of luck!

John L Rice

PS - you will absolutely LOVE your MOTM-300 and MOTM-440!!!! :-)


-----Original Message-----
From: motm@yahoogroups.com [mailto:motm@yahoogroups.com] On Behalf Of Gozer
le Gozerien
Sent: Saturday, June 20, 2009 10:52 AM
To: motm@yahoogroups.com
Subject: [motm] new 650 user

hi all :)

just got my 650 and i have little "easy" questions coming in.
 
1 - is there a way to transpose (octaves and 1/2 tones) with the 650 or do
you have to do it with the midi keyboard only ? can't find that feature in
the 650 or in pdf.

2 - is there a way to tune/scale the 650 on the VCO you'r using ? you know,
you tune a low note then you play a high note and set the MIDI to CV so both
notes are in tune. For the moment the dotcom Q106 i have sound out of tune
after 2 octaves :P.

650 rocks ..fantastic panel. it's my first motm and i can't wait for the 440
& 300 i ordered :P !
thx all . sure i'll come back for more questions ;)








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