MOTM

OK Folks, talk is cheap.

After noodling around with designs for a couple of years, I've 
decided (with Paul's blessing) to offer an MOTM sequencer for public 
consumption. Now I know that nothing stirs up a hornet's nest faster 
than asking for input on a sequencer design, but that's what I'm 
doing. Just read my initial thoughts on the project's direction, and 
suggest accordingly. If you ask for something completely outside of 
the scope of the design, I'll feel free to ignore it!

Here are my initial thoughts on the project, in random order:

1. It will be full MOTM format, with regular sized knobs, etc.
2. It will NOT be modular like SuperMoe. Yes, I'm still going to do 
SuperMoe if only for myself, but call this one "MiniMoe". I'd like 
for it to be affordable enough that I can sell at least 30 or so. So 
it has to fit on a single panel.
3. The clock will be external. Real estate is precious, LFOs are 
cheap, and I'd rather put sequencer features there instead.
4. It will most probably be PIC driven, but none of the CV outputs 
will pass through a DAC - they will remain in the analog domain.
5. It will exist as either a full kit or as a partial kit. I'm 
leaning toward the latter right now - a Stooge front panel, pcbs and 
preprogrammed PIC, you supply the rest. I'm open to feedback on this.
6. This is a step sequencer, not a pattern sequencer. Don't ask for 
the ability to store sequences and chain them together in playback.
7. I don't plan on offering an internal quantizer either. Buy a 
MiniWave instead.

Format - there are a couple possibilities here. 

A minimal module might be 5U wide, with a 4x4 pot grid. It would be 
the least expensive, and would do basic 8x2 or 16x1 step sequencing. 
There would not be room to supply the full complement of inputs and 
outputs for every stage.

A more deluxe version might be 8U wide. It would probably have room 
to do something along the lines of the Moog 960. Lots of pots, jacks, 
and switches to buy and wire.

So, is there any interest in this thing? Fire away.

Moe (ducking)

The idea of a partial kit "a la Tony Allgood" I think is the best way 
of encouraging people to afford big projects that may include a very 
large number of parts. In this sense, in my opinion, the super moe 
project would be welcome by lots of folks and the big and several 
pcbs would all be easily probably purchased. It would take much more 
time before people would finish building the super moe but lots of 
them would start  buying the PCBs, if this is correct I don't see why 
not thinking seriously about starting producing the Super Moe instead 
of a dramatically simplified version?
Enrico Italy



--- In motm@y..., "mate_stubb" <mate_stubb@y...> wrote:
> OK Folks, talk is cheap.
> 
> After noodling around with designs for a couple of years, I've 
> decided (with Paul's blessing) to offer an MOTM sequencer for 
public 
> consumption. Now I know that nothing stirs up a hornet's nest 
faster 
> than asking for input on a sequencer design, but that's what I'm 
> doing. Just read my initial thoughts on the project's direction, 
and 
> suggest accordingly. If you ask for something completely outside of 
> the scope of the design, I'll feel free to ignore it!
> 
> Here are my initial thoughts on the project, in random order:
> 
> 1. It will be full MOTM format, with regular sized knobs, etc.
> 2. It will NOT be modular like SuperMoe. Yes, I'm still going to do 
> SuperMoe if only for myself, but call this one "MiniMoe". I'd like 
> for it to be affordable enough that I can sell at least 30 or so. 
So 
> it has to fit on a single panel.
> 3. The clock will be external. Real estate is precious, LFOs are 
> cheap, and I'd rather put sequencer features there instead.
> 4. It will most probably be PIC driven, but none of the CV outputs 
> will pass through a DAC - they will remain in the analog domain.
> 5. It will exist as either a full kit or as a partial kit. I'm 
> leaning toward the latter right now - a Stooge front panel, pcbs 
and 
> preprogrammed PIC, you supply the rest. I'm open to feedback on 
this.
> 6. This is a step sequencer, not a pattern sequencer. Don't ask for 
> the ability to store sequences and chain them together in playback.
> 7. I don't plan on offering an internal quantizer either. Buy a 
> MiniWave instead.
> 
> Format - there are a couple possibilities here. 
> 
> A minimal module might be 5U wide, with a 4x4 pot grid. It would be 
> the least expensive, and would do basic 8x2 or 16x1 step 
sequencing. 
> There would not be room to supply the full complement of inputs and 
> outputs for every stage.
> 
> A more deluxe version might be 8U wide. It would probably have room 
> to do something along the lines of the Moog 960. Lots of pots, 
jacks, 

> and switches to buy and wire.
> 
> So, is there any interest in this thing? Fire away.
> 
> Moe (ducking)

hello all,

i like the mini-moe idea - and since i have little experience in sequencer
modules, would welcome it in almost whatever form it arrived. i think the
panel / pcb / pic only combo would be best for a kit, it saves hassle on
moe's part, and keeps the erm percieved cost down for the rest of us
i'd err on the side of the larger format - and i'd prefer not know how much
the switches / pots / jacks etc add up to until it's too late...

and maybe, as enrico touched on - if this is a success, then next stop
super-moe kits..?! (sotm)

cheers
paul b
sheffield

In a message dated 2/17/02 12:46:56 PM Pacific Standard Time, endiendi@... 
writes:


> the super moe 
> project would be welcome by lots of folks and the big and several 
> pcbs would all be easily probably purchased. It would take much more 
> time before people would finish building the super moe but lots of 
> them would start  buying the PCBs


I agree with this. I really like the idea behind the Super Moe (modularize 
all the internal functions of a sequencer to make the most powerful version 
of a sequencer) but I agree if this idea were ever to be taken on by either 
Paul or Moe, it would be a while before they sold enough of these "sub" 
modules to see a profit. It would also be a daunting outlay of cash before 
any user would have anything like a sequencer.

In that regard, I favor Moe's idea of having a more basic sequencer available 
-- besides, a lot of interesting things can happen with multiple sequencers 
running at one time.

Assuming a larger MOTM analog sequencer will eventually become available, 
what about reducing the size even smaller to a 3U 8 X 1 (maybe a 4 X 2) with 
all the basic features (clock in, hold, up/down, reset, etc.) and an 
additional chain out to link several of these together to make longer (or 
polyphonic) sequences.

What is the projected cost of the finished project to the user? And what kind 
of op amps will you be specifying -- low drift expensive ones perhaps?

JB

A partial kit with no quantizer that requires an external clock is 
perfect. I'd prefer to see a full complement of inputs and outputs 
for each stage. This would make it much more useful to interface with 
other gear down the road (like a SuperMoe or MOAS). Rather than an 8U 
wide module that does 8x2 or 16x1, how about a 4U MiniMoe that does 
8x1 and allows expansion to more MiniMoes? Then two modules could 
provide 8x2 or 16x1, and three could provide 8x3 or 24x1 (or even 
16x1 plus 8x1).

In-Reply-To: <001501c1b7fa$009423a0$411ca6c3@pavilion>
> hello all,
> 
> i like the mini-moe idea - and since i have little experience in sequencer
> modules, would welcome it in almost whatever form it arrived. i think the
> panel / pcb / pic only combo would be best for a kit, it saves hassle on
> moe's part, and keeps the erm percieved cost down for the rest of us
> i'd err on the side of the larger format - and i'd prefer not know how much
> the switches / pots / jacks etc add up to until it's too late...
> 
> and maybe, as enrico touched on - if this is a success, then next stop
> super-moe kits..?! (sotm)
> 
> cheers
> paul b
> sheffield



All of the above,

cheers

(lazy)Keith

http://home.freeuk.net/lowpass

Well let me start off by saying emphatically: I would be interested in *ANY*
kind of MOTM sequencer.  This is terrible news for my bank account.

My very humble thoughts follow...

> --MOE--
> 2. It will NOT be modular like SuperMoe. Yes, I'm still going to do
> SuperMoe if only for myself, but call this one "MiniMoe". I'd like
> for it to be affordable enough that I can sell at least 30 or so. So
> it has to fit on a single panel.
> -------
That makes sense - but for a different reason for me: As I do not have much
experience with analog sequencers, it would be nice to start out with
something integrated rather than separate modules.  Then later, armed with
knowledge, go the separate module route.

> --MOE--
> 3. The clock will be external. Real estate is precious, LFOs are
> cheap, and I'd rather put sequencer features there instead.
> -------
Excuse my ignorance - does requiring a LFO as an external clock source give
up any funcionality over having an internal clock?  If not, I agree with
this.

> --MOE--
> 4. It will most probably be PIC driven, but none of the CV outputs
> will pass through a DAC - they will remain in the analog domain.
> -------
Excellent.

> --MOE--
> 5. It will exist as either a full kit or as a partial kit. I'm
> leaning toward the latter right now - a Stooge front panel, pcbs and
> preprogrammed PIC, you supply the rest. I'm open to feedback on this.
> -------
I would prefer a partial kit, so long as the parts are not too hard to
obtain.

> --MOE--
> 6. This is a step sequencer, not a pattern sequencer. Don't ask for
> the ability to store sequences and chain them together in playback.
> -------
No arguement here.

> --MOE--
> 7. I don't plan on offering an internal quantizer either. Buy a
> MiniWave instead.
> -------
Another ignorant question - would using a single miniwave for quantizing
provide the same level of functionality as a built in quantizer? If so, this
makes sense.

A comment on format: I agree with JB that an even smaller 2x4/1x8 format
that offered full functionality and that could be chained to addl. modules
would be preferable over a larger format with fewer features.  It would also
mean you would sell more of them. :)

A question: will this sequencer require an additional power source of +5V?

Thanks Moe for asking for our input (and for enduring my comments).  This
process really enhances the MOTM experence.
George

PS: Don't forget plenty of blinky lights!

On Sunday, February 17, 2002, at 05:03 PM, Scott Juskiw wrote:

> A partial kit with no quantizer that requires an external clock is
> perfect. I'd prefer to see a full complement of inputs and outputs
> for each stage. This would make it much more useful to interface with
> other gear down the road (like a SuperMoe or MOAS). Rather than an 8U
> wide module that does 8x2 or 16x1, how about a 4U MiniMoe that does
> 8x1 and allows expansion to more MiniMoes? Then two modules could
> provide 8x2 or 16x1, and three could provide 8x3 or 24x1 (or even
> 16x1 plus 8x1).

I like this idea. Many times I need just a hand full off stages (3 or 5),
and would rather have several small sequencers that I could use
independently. If I need a monster sequence I can still chain them
together. You may even be able to get an 8x1 into a 3U width. That
would keep them cheaper and I could buy more of them :-). I'd
even buy a 4x1.

Tomy

Although a quantizer is not in the offing for the MiniMoe, I would like
to see a dedicated quantizer module available, as I think this use for a
MiniWave is to great a loss to other functionality of the module.

Scott

"It is better to cherish virtue and humanity, leaving much to free
will ... than to attempt to make men machines and instruments of
political benevolence.  The world as a whole will gain by a liberty
without which virtue cannot exist."
Edmund Burke
------------------------------------------------------
mate_stubb wrote:

> 
> 7. I don't plan on offering an internal quantizer either. Buy a
> MiniWave instead.
>

Another thing I worry about (thought I don't have a miniwave) is the 
relative low resolution of the 8-bit setup in the miniwave... is 255 
levels enough to quanitize accurately, in a chromatic way?  Or is it 
just better for octave-octave-octave stuff?  Just curious what your 
experiences are, and, of course, if there are any "official" plans 
for a quantizer.  I agree that using a MV just for quantizing is 
probably a waste.

--- In motm@y..., "Scott Evans, Gen Mgr" <esresource@e...> wrote:
> Although a quantizer is not in the offing for the MiniMoe, I would 
like
> to see a dedicated quantizer module available, as I think this use 
for a

> MiniWave is to great a loss to other functionality of the module.
> 
> Scott
> 
> "It is better to cherish virtue and humanity, leaving much to free
> will ... than to attempt to make men machines and instruments of
> political benevolence.  The world as a whole will gain by a liberty
> without which virtue cannot exist."
> Edmund Burke
> ------------------------------------------------------
> mate_stubb wrote:
> > 
> > 7. I don't plan on offering an internal quantizer either. Buy a
> > MiniWave instead.
> >

Short answer, no.
 
Long answer:
The miniwave uses a DAC0800LCN.  Full scale error is +-1 Least
Significant Bit and nonlinearity is 0.19%.  Just looking at the
nonlinearity, 0.19% of 10 volts, or the full scale Miniwave output, is
19 millivolts.  1 volt = 1 octave, 1 semitone = 1/12 = 83 millivolts,
and 1 cent = 83mV/100 = .83 mV.  19mV/.83mV = 22.9 cents.  So that's the
accuracy you can expect from the Miniwave.  You may get better results,
but that's not guaranteed.
 
Pitch discrimination varies on the context.  For monophonic lines you
may only be able to discern 3-8 cents of pitch resolution.  For chords,
where you can hear the beating of the harmonies, pitch discrimination
can be better than 1 cent, particularly if you're using a just tuning.
For equal temperament, 1-2 cent accuracy is adequate.
 
As a comparison, the MOTM-300 VCO published specs correlate to a pitch
accuracy of better than 1.4 cents from 50 Hz to 1600 Hz, and better than
4.4 cents from 25 Hz to 6400 Hz.
John Loffink
jloffink@... 

-----Original Message-----
From: sucrosemusic [mailto:sucrosemusic@...] 
Sent: Monday, February 18, 2002 7:59 PM
To: motm@yahoogroups.com
Subject: [motm] Quantizing
 
Another thing I worry about (thought I don't have a miniwave) is the 
relative low resolution of the 8-bit setup in the miniwave... is 255 
levels enough to quanitize accurately, in a chromatic way?  Or is it 
just better for octave-octave-octave stuff?  Just curious what your 
experiences are, and, of course, if there are any "official" plans 
for a quantizer.  I agree that using a MV just for quantizing is 
probably a waste.

You can try this, but it's much easier to buy a 12 to 16 bit D/A
converter.  Basically the problem you're trying to solve, D/A converter
accuracy, has already been perfected by IC designers over the last 20
years.
John Loffink
jloffink@... 

-----Original Message-----
From: J. Larry Hendry [mailto:jlarryh@...] 
Sent: Tuesday, February 19, 2002 10:45 PM
To: MOTM List
Subject: Re: [motm] Quantizing
 
I have l long been thinking about a quantizer.  My thought process was
that a very accurate circuit could be built in the 8 bit format IF one
used a ADC to get the digital quantities, but avoided the 8 bit DAC by
going completely analog on the output.  Then each of the 8 elements
could be trimmed accuracy so when you added the elements each together
you would have much greater than the accuracy expected from a 8 bit DAC.
I can see Paul shaking his head and sighing at me right now.  But, I
have been thinking seriously about a replacement for the 822 when those
PCBs are gone that uses pots instead of rotary switches.  So, trimmer
count would be considerable less.  Of course, then your basic circuit is
a quantizer.  I have done no development yet because of other projects,
my need to learn more, and the (cough, cough) significant stock of 822
PCBs I would like to make a dent in first. :)  And, I fully admit to
knowing almost nothing about it and being significantly under-qualified
for the job.  So, I'll probably play with it anyway.
 
On a related question, where would one normally expect the analog out to
track the input relative to step points.  To simplify the example, let's
assume 1 volt steps.  Would the output be desired to change from 1 to 2
volts at 1.5 or 1.9999 on the input?  I don't see that is really
matters.  But, I am still pretty ignorant on the subject.
 
Seems the 8 bit DAC might be fine for a mono synth and single
oscillator, but would never do where oscillators might beat together.  I
have a couple of the PAiA 8 bit MIDI 2 CV 8s that I use with stuff other
than my MOTM modular.  For my mono synths (like my Micromoog) that 8 bit
resolution seems to be OK.
 
Larry

That is a very good DAC. As a matter of fact, that's the same DAC I used in
the Expressionist.

(Hmmmm, a lot of people have been talking about quantizers lately)

Tony Karavidas
Encore Electronics

http://www.EncoreElectronics.com

Designers of "The best MIDI to CV converter on the planet." -Keyboard Oct.
1997

-----Original Message-----
From: Gur Milstein [mailto:gur_mil@...]
Sent: Wednesday, February 20, 2002 5:35 AM
To: John Loffink; 'J. Larry Hendry'; 'MOTM List'
Subject: Re: [motm] Quantizing


Hi.
I have just made a pcb for a 16bit quantizer.
it use the AD669BN very high accuracy DAC , it is a 45$ chip .
I powered it up yesterday and connect it to the MOTM300 and the result are
great.
it is a 4 channel quantizer with 3 bank of 8 scale each.
pictures are coming soon.

thanx
Gur Milstein

While I would agree with the value of 12/16bit D/A, especially in
applications where you are going to hear very accurate digitally derived
frequencies along with equal volume analog VCOs, the performance of 8
bit D/As is often better than you might expect. For example, after
calibrating the quantizing function of (VERY) many MWs, I can report the
following as pretty typical. This is one on the test bench today (Bank
and Wave 15):

0.9980V
1.9983
3.0049
4.0051
5.0009

The ideal voltages are 1, 2, 3, 4, and 5 Volts. The calibration point is
5V (off 0.9mV due to twitchy tech).

The point is that for a lot of synthesizer uses, utter perfection is not
a requirement. But the limitations of any gear should be kept in mind to
avoid frustration.

With the quality converters available today, no new MIDI to CV design
should ever use an 8 bit converter.
___________________
John Blacet
Blacet Research
http://www.blacet.com

At 1:59 AM +0000 2002/02/19, sucrosemusic wrote:
>Another thing I worry about (thought I don't have a miniwave) is the
>relative low resolution of the 8-bit setup in the miniwave... is 255
>levels enough to quanitize accurately, in a chromatic way?  Or is it
>just better for octave-octave-octave stuff?  Just curious what your
>experiences are, and, of course, if there are any "official" plans
>for a quantizer.  I agree that using a MV just for quantizing is
>probably a waste.

In my experiences, the MW is more than adequate as a quantizer. I've 
been using a MW as a quantizer for almost a month now and despite the 
8 bit math saying otherwise, I haven't yet found an instance where 
the slight error was objectionable nor even noticeable. If you plan 
to use your MOTM as a digital accurate reference oscillator, then the 
quantizing error will be noticeable as a slow beating on some notes 
(some notes beat more than others). But in actual use as an analogue 
synth (with three oscillators tracking each other, LFOs plugged into 
the FM and PWM inputs, and a delay unit adding a final chorus), a few 
cents of quantizing error is irrelevant.

Hi .
I made some photo's of the new 16bit quantizer check the attach zip file.
it is 4 channel multiplex meaning you can connect 4 analog sequencers and
convert which one that you like by trigger the "next channel" banana input.
so a 64 note sequence can be accomplish easily by using 4 analog sequencers
of1x16 each.
the channel order can be change in real time by using the "ch1" and
"up/down" banana
input's.
there are also 4 transpose cv inputs which are basically a cv mixer that sum
the amount of cv1 and transpose1 dc that comes from  different analog
sequencers that run's at divide clock rate ,so for exemple for every 2 cycle
of the cv1 sequencer the transpose sequencer would advance to the next step
and transpose the sequence up or down.
there are also 3 bank of 8 scale while scale can be selected manually or by
gating the scale's banana jack's.
it is very nice when you change this scale's from a analog sequencer and the
LED's are corresponding to it .
but that is not all , infect the most important aspect of this quantizer is
its convert method.
three is NO internal clock at high frequency  inside to run the conversion
sequence ,instead three is a banana jack for triggering the conversion
sequence from any analog sequencer logic gates or other control modules.
this conversion method gives the quantizer its great groove musical feel
when converting  note after note by the analog clock which is the MOTM-300.
the total cv output error is max 250uV and the trimmers are cermet 100ppm/c
and the feedback resistors are 25ppm/c "HOLCO".


sorry for that long e-mail.
thanx
Gur Milstein

ANALOGIC-ACS







That is a very good DAC. As a matter of fact, that's the same DAC I used in
the Expressionist.

(Hmmmm, a lot of people have been talking about quantizers lately)

Tony Karavidas
Encore Electronics

http://www.EncoreElectronics.com

Designers of "The best MIDI to CV converter on the planet." -Keyboard Oct.
1997

-----Original Message-----
From: Gur Milstein [mailto:gur_mil@...]
Sent: Wednesday, February 20, 2002 5:35 AM
To: John Loffink; 'J. Larry Hendry'; 'MOTM List'
Subject: Re: [motm] Quantizing


Hi.
I have just made a pcb for a 16bit quantizer.
it use the AD669BN very high accuracy DAC , it is a 45$ chip .
I powered it up yesterday and connect it to the MOTM300 and the result are
great.
it is a 4 channel quantizer with 3 bank of 8 scale each.
pictures are coming soon.

thanx
Gur Milstein






Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

Gur,

Looks VERY nice - a quantizer sequencer!

A couple of questions - what gear are you interfacing it with that 
made you decide to use banana jacks, and how come you didn't order 
some nice custom matching Stooge panels for them<g>!

Moe