Made a analog style sequencer using an Apple II.

It’s equipped with a Mountain Computer ADC / DAC board.

The board can read in 16 channels of voltages.

It can also output 16 channels  of voltages.

Voltage ranges are -5 volts to +5 volts. 

Resolution is 8 bit whether reading or writing.

Using a blank piece of aluminum panel here, 16 NOS Moog 100K linear pots and some new Cosmo (Moog) knobs, I built a crude 16 stage sequencer within 2 hours.

I also included 16 capacitors that cured a small problem with channel to channel interactivity.

I then programmed a traveling bar graph displaying notes as vertical bars of varying height.

The top of each bar would flash as that particular note played.

All software is written in Applesoft BASIC. 

The code was very short.

Making a change such as the choice between V-trig and S-trig outs was one line of code.

Using one of the game paddle inputs, I added a pot for use as tempo.

I also added a gate output jack, along with both a positive CV out channel as well as an inverted CV output jack. 

Again, inversion was as easy as adding one line of code.

The sequencer can be run forwards or backwards.

It could be a single channel 16 stage analog sequencer.

Or an 8 stage with variable duration per stage via the second row of 8 pots.

The Apple’s stock cassette jacks could also be programmed to allow syncing the sequencer either to or from an external source, change the direction of the sequence, etc.

In hardware, I plan on adding some opamps to offset the CV out(s) to 0 – 10v instead of -5 to +5 and additional drive capability.

I may also add a gate LED and driver. 

In software, I plan on adding variable stage length, duration (as an 8 stage) and a quantizer.

Also a preference page allowing choice of colors for the display and other settings.

A method of changing direction on the fly would be desirable also.

One problem: The bar graph display does not update the note heights until the next cycle of the sequencer. Therefore, changing stages while playing does not show the changes graphically without a considerable delay.

This is me testing out a quickly built 16 stage sequencer using an Apple //e computer.

It only took about 3 hrs to build the panel and write the (pretty crude) software.

LOTS of possibilities to explore in the future though.

The Apple has a Mountain Computer 16 chan ADC / 16 chan DAC.

Everything written in Applesoft BASIC.

The synth is a Moog 55A that’s here for service. 

Nothing serious going on here.

Building the sequencer and taking the video were just for fun. 

Short story: http://www.youtube.com/watch?v=mRFRFnrNni0

Long story:

I (very quickly) hacked together an analog style sequencer using an Apple II computer equipped with an old Mountain Computer ADC / DAC board.

This board can read in or output 16 channels of analog voltages.

Voltage ranges are -5 volts to +5 volts (though I can change this.)

Resolution is 8 bit, but it’s still fairly accurate hitting note CVs closely.

I made the panel from a piece of scrap aluminum I found here

Used 16 100K linear pots (NOS Moog) and some new Cosmo (Moog style) knobs.

Built and wired it up along with some vinyl lettering in around 2 hrs. 

For software, I programmed a traveling bar graph that displays notes as vertical bars of varying height.

The top of each bar would flash as that particular note plays.

One CV out jack is the “normal” mono out. 

A 2nd CV out jack is right now programmed as being the same notes, but inverted.

The gate out jack can be whatever- V-trig, S-trig, pulse. 

In the video it’s making S-trigs for the Moog 911 envelope generator.

Software is written in Applesoft BASIC. 

(Comes built-in on the Apple.)

The code was incredibly short. I couldn’t believe how little it takes to write something like this.

Making any change such as adding a quantizer, variable note durations or sequence length takes about 1 or 2 lines of code.

Right now it’s programmed as a single channel 16 stage analog sequencer with mono CV out.

But I might make it be an 8 stage with the second row of 8 pots changing the duration of the first 8 stages.

A 30+ year old computer driving a 30+ year old synth can still be a lot of fun.

This critter could also be programmed to allow syncing it to or from an external source.

You could even make it go backwards or write a “performance” to disk without too much work.

File date: 12/21/2010

File date: 11/26/2004

Why the white Arp Odyssey is not always “the better Odyssey”

1. White Odys have more trimmer adjustments and are more difficult to calibrate.

2. White Odys used a three buss keyboard using silver plated spring contacts.
Later units used a two buss action with gold plated J-wires.
Therefore, black Odys have less contacts necessary, better conductivity, less or no tarnish, self-wiping contacts and are easier to adjust and repair.

3. It’s painted thinly. The board standoffs cause front panel paint cracking.
Black Odys are painted more thickly.

4. White Odys are older and thus their sliders and switches are more worn and have had more time to accumulate dust.
Capacitors, resistors, trimmers, rubber keyboard standoffs and bushings are older too.
Older synths on average have also seen more service, more wear and vibration.

5. It’s white. This was changed to black later because it was too annoying on brightly lit stages.

6. White Odys have their power switch mounted to a PCB.
Removal of that PCB is more difficult than in a black Ody.

7. White Odys have fewer interface jacks.

8. White Odys actually sound *less* Moogy than black ones because their filters are -12db, instead of -24db like Moogs.
It should also be noted that Moog never sued Arp over the filter design.

9. White Odys have a transistor noise source, while later black Odys used a zener diode.
Zeners make a more consistent noise with less spikes that can damage speakers.

10. White Odys have slide switches which have a bracket in front of the contacts, making them harder to clean than black Odys.

11. The keyboard connector on Black Odys is one piece.
White Odys have the same connector, plus an extra wire attached to the extra buss of their three buss keyboard.

12. Later black Odys have a removable power cord and a hinged front panel making service easier. Instead of 14 screws to remove, there’s 4.

13. Later black Odys have PPC and can thus inject the LFO equally into both oscillators simultaneously while playing. Impossible on a white Ody.

14. White Odys use two additional digital CMOS chips in their oscillators, making them more unreliable and less analog than black ones.

15. White Odys used smaller rubber feet, which can shear off more easily than black Odys.

16. White Ody panels used no welds. Black Odys welded their keyboard mount pieces and corner seams.

All in all, black Odysseys are more reliable, more stable and cheaper to buy and maintain.
It’s only logical that Arp strived to *improve* the design over the years.

Original File Date: 1/24/1996
Original file appears below, with all typos intact.

—————————————————————————-
-SYNTH MASTERS-
—————————————————————————-
[*Serge.jpeg*WIDTH288HEIGHT216]
—————————————————————————-
Kevin Lightner is one of a rare breed. He has put together what must well be
some of the largest modular systems on the planet. Systems we mere mortals
could only dream of owning (or perhaps even just touching) have passed
through his hands. If the names Serge (66kjpeg), Aries (66kjpeg), or maybe
more familiar names like Moog (50kjpeg) and Emu make your heart race prepare
to meet the man who puts these monster modulars together, as Recoil coaxes a
short interview and photos out of Mr. Kevin Lightner “Synth Master”!
—————————————————————————-

THE INTERVIEW
—————————————————————————-

Recoil: What got you started as a vintage synth builder?
Kevin: I Built a Paia Gnome/OZ and 4700/s when I was 14.

Recoil: What was the first system you put together and where did it end up?
Kevin: The first REAL modular I built was the big Moog and Roland (83kgif)
system for Hans Zimmer. It is the WALLS of his studio and it took me two
years!)

Recoil: Have you kept any for yourself?
Kevin: None! I have very few synths myself, although I’ve been playing keys
about17 or so years.

Recoil: What would you consider your crowning acheivement as far as:
1. Aquiring a hard to find unit?
Kevin: I don’t acquire. I leave that up to the brokers and owners. I
restore, improve, repair, modify, assemble… but I don’t buy or sell. Keeps
me respectable!
2. Building the most massive systems?
Have you had many struggles to get them working?
Kevin: HAAAA!! Struggles? Ever TUNE a 58 vco synth? Actually, they all worked well
upon powering up, but there’s a lot done before that ever happens.

Recoil: How on earth do you source these units, I mean I’m sure most people
in the know have never even seen a live Buchla or Emu modular. Aren’t they
extremely rare and hard to find?
Kevin: Again, I don’t. And yes, they are hard to find. Harder every day…!

Recoil:What would you consider the most rare system and modules at the
moment?
Kevin:Rare doesn’t necessarily mean good or desired. The Ppg modules,
Projekt Elektronik, Wavemaker… all of these are pretty rare. As far as
rare and desired in a major way, the Bode frequency shifter seems to be
requested a lot.

Recoil: What would you consider the most unusual system/module?
Kevin: Buchlas and Serges are pretty unusual from a standard audio/cv
standpoint.There are fewer imposed limitations with those systems. I
personally love the Digisound VCDO as a strange module! The Blacett
frequency divider is another rare favorite.

Recoil: You have put together some massive systems, for Hans Zimmer and
others, do these guys actually use all these modules or are they just rich
collecters?
Kevin: Both. As far as Zimmer is concerned- He does have a lot of equipment-
no arguement there- but he is very talented and successful, even if he was
to just use it as inspiration, who’s to agrue with his means? It works for
him. It’s much like a painter- he may have 20 greens on the easel, uses only
2 for months, but when he wants the others they are there. As far as your
question- yes, Hans uses the Moog, Roland, Emu and Polyfusion as needed.

Recoil: Do you end up doing alot of maintenance for these people, and don’t
you have a hard time finding replacement parts?
Kevin: No, I do very little maintenance on the systems I’ve built. Generally
they don’t travel. Most systems get new linear power supplies, new trim
pots, new connectors, etc. They are actually very stable. As far as parts, I
have a wealth of suppliers for what I need. I can order Switchcraft jacks,
Moog knobs, semiconductors, pots, switches, just about everything is still
available. Special items like ribbon controller ribbons and custom things
like that are often difficult, though.

Recoil: What system if any are you working on now?
Kevin: I am doing a very elaborate custom synth for Hans now. I have a
repackaging of an Oberheim 4 voice/ mini seq with very complete MIDI for
Mark Isham.There is a very modified 2600 I’m finishing up, with MIDI and
lots of mods. I don’t modify Moogs and Arps and rare synths unless they are
ALREADY drilled up!
Recoil: that sounds like a rather wise decision… 🙂

Recoil: If you could put together any system you desired, which would it be?
Kevin: EEEEEKKKK!!!! I like ’em all for one reason or another. Polyfusions
and Sys-100’s are good later analog designs, though they are pretty tame
compared to a Serge as far as functionality.
Recoil: If you can, name your top 5 systems/modules and tell us why you
choose these?
Kevin: Moog 55- good compliment- good stability. Oberheim 8 voice- Good
sound- well made- Arp2600- well compromised “modular”- good sound, MiniMoog-
just a great sound- great glide- Serge NTO- Great oscillator. period,

Recoil: Thanks for your time Kevin, we hope visitors to this page don’t soil
your Synth jpegs too severly while their busy drooling! 🙂
—————————————————————————-

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