Minimoog Model D Replacement Contact Board

[Kevin Lightner]

I haven't been on this forum for a while, but have something exciting (at least for me) to share.
I hope you don't mind hearing from me on stuff like this.

For the past couple years I've been working on a project to cure one of the largest problems with the Minimoog model D: the keyboard contacts.
As any Mini owner knows, can they require cleaning and adjustment often.

While the entire keyboard could be replaced with the same action found in the Voyagers, a Fatar, it would require additional circuitry and would also change the look and feel of the classic model D.
Another method, one that retains the original keyboard, would need to be devised.

After several years of work on my own and finally with the added skills of a very talented engineer named Howard Davis, I'm proud to announce a new optical contact board for the Minimoog D.

In simple terms, one rips out their old contact board and buss bars and installs this in place.
No wiring or soldering.
It plugs directly into the original 6 pin keyboard connector provided on every model D.
Key presses are sensed by reflective optical (IR) sensors.

Here are some features:

16 bit control voltage accuracy.
Low note priority (just like stock)*
Extremely low power consumption
MIDI IN, OUT and Thru, including wireless MIDI option*
Optical sensor based. Sensors don't touch anything and there's nothing to wear out.
No contact cleaning.

*additional software is now being developed for other key modes (high, low, last), keyboard inversion (Zawinul mode), alternate scales, MIDI functions, arpeggiator, chromatic glissando, LFO, etc.)

Right now, the basic firmware is operational and emulates an original Mini keyboard action perfectly (mono, low note priority.)
The software is contained in non-volatile" flashable" memory.
The MIDI code, key priority and some other features have been completed, but not yet tested or loaded into the firmware.
I expect a few weeks more, but may happen sooner.

I have enough boards and parts now to make only a handful at the moment, but am taking preorders or deposits.
Delivery expected in 30-60 days.
Cost is $395 for the basic opto contact board replacement and $495 with the MIDI firmware and connectors.
(All the MIDI hardware is already included on every board.
Only a software upgrade needs to be installed.)

No need for a separate MIDI to CV converter.
It will even allow the Moog to be used as a sound module, while the keyboard is used as a MIDI keyboard. (local off supported.)

Additional features will be available either by sending in your MPU chip for reprogramming or purchase of an updated chip (they're socketed) for about $30-50 or so depending on new features provided.
Wireless (IR-Infrared or ghz microwave) MIDI is also being developed and will be offered later.
The board already supports this feature too, but the external box must be developed.
It'll just plug right in once it's available.

Others versions are also being developed for the Arp Odyssey and perhaps other synths.

Anyway, photos and video are worth a thousand words:

http://www.synthfool.com/optoboard.jpg

http://www.synthfool.com/optos.jpg

http://www.youtube.com/v/Ifa7yNkkNf8


PS: More Taurus T1 replacement contact boards have been produced and are available now.
(non-optical, but very reliable and durable)

A Taurus T2 contact board.. with MIDI... will also be made available soon.

I have no plans to make a T1 board with added MIDI- Buy a new T3 instead!

Thanks for reading!
Kevin Lightner / Synthfool

[museslave]

Kevin, I just watched your video on this very subject.
What a fantastic idea.
I'm an obnoxious purist when it comes to my Mini, and although I've always stated I would NEVER modify it in any way, I guess I was wrong. This is a product I will gladly invest in.
I also think your price is quite reasonable.
Well done!

[MC]

Kevin builds Good Stuff. I got one of his replacement contact boards for the T1 and it has held up great.

[dr_floyd]

Brilliant!

What is the preorder/deposit process?

How will the MIDI i/o jacks be mounted?
Will it still be possible to tap into the CV/gate directly from the keyboard concurrently with MIDI i/o?
Is Howard Davis the same engineer who did some of the Electro-Harmonix designs?

Thanks for you continued innovation.

[Kevin Lightner]

Thanks for the kind feedback.

I'm not into modding Minis unless there's a very good reason.
Few mods are done cleanly with future service in mind too.
They lower the value of the instrument while making service more costly.

These contact board solutions are different to me.
They take an otherwise good synth and improve one of their big weak spots.
Adding MIDI saves other Minis from having to be drilled up for other types of MIDI mods.
(The Kenton needed a *wood router* to install!)

I'm not certain how the financial particulars are being handled yet.
I'm pretty sure my wife will add something to our store soon.
(http://www.minimoogs.com/store)

The MIDI jacks can be mounted if so desired (drilled into the case or wood), but my recommendation would be to run the cables out the back- through the round hole in the back of the wood where the other wires go.
A wire tie inside could take care of strain relief and MIDI jacks are available in cable mount female types.
So that's the idea for now.
I can provide normal panel mount jacks as well, but would rather those not be the only option or people will drill up their Minis.

Yes, the MIDI and CV all peacefully coexist.
Even the low-note priority logic is applied to the incoming MIDI and both the keyboard and incoming MIDI are merged under normal conditions.
One could hook up their sequencer and play both the Mini live while sending out that MIDI, then hit play on the sequencer and have it play back... with the Mini still able to send out MIDI if a key is played (and none other are being played.)

I can also provide CV and Gate output jacks to control other devices, either via the Mini's keyboard or incoming MIDI.
The MIDI channel is now set by holding down a key note while turning the Mini on. (it remembers it via non-volatile ram.)
This might change or be overridden later as more features are added.
I foresee a "second page" of features accessible by holding down both the top and bottom keyboard notes simultaneously for about 2 seconds.
It could then allow other keys to change functions, parameters and whatnot.
There's even a small beeper speaker on the board that could provide audible feedback you've entered or exited 2nd page.
I could even program it to play some quick musical line on the Mini as feedback.
But wouldn't it be cool to say, hold down these 2 keys, then hit say an F# or whatever and suddenly the keyboard is inverted or in another scale?
An arpeggiator or sequencer is even possible.
The CPU is running at 10mhz. Plenty fast for stuff like this.

Another option: For about $100, I could even sell the programmer that programs these microprocessor chips.
Then I could upload new updates and owners could plug it in via USB for a firmware update at home.

One remaining issue is whether it will be sold as a user-installed device or will require an owner to send in their keyboard action for retrofitting.
I think some people would have no problem with the installation and adjustments necessary for success, but not sure everyone could do it right.
It requires patience and following directions: two things often found in short supply.

Finally, no I don't think it's the same Howard as EH's engineer.
But this Howard Davis is simply an amazing engineer and person in general.
He *donated* his time for this project because he thought it would be fun and believed in the idea.
Payed it forward.
Once some of these things sell, he's going to get some very nice presents regardless of his generosity.
But for now, I have lots of assembly to do and will need to sell a few in order to fund the parts in order to make more.

And thanks for the kudos, MC.
The 2nd rev of the Taurus boards are red and very slightly improved for assembly and installation.
The first customer was the bass player for the unsigned LA band "Red Cortez."
Seems fitting

[latigid on]

Wow, great upgrade Kevin! No Mini here, but I'm sure many will appreciate the work.

Is that a PIC you are using? I'm no programmer, but what about bootstrapping your micro so updates can be sent over MIDI? Just a thought.

[Kevin Lightner]

Is that a PIC you are using? I'm no programmer, but what about bootstrapping your micro so updates can be sent over MIDI? Just a thought.

It's an electrically programmable MPU (basically a PIC), but since not every unit ordered will have MIDI, I thought it best to upgrade them via individual chips or via USB programmer.
It's not that it can't be done via the MIDI units sold either, but it gives me the willys to think about because if the transmission is botched for any reason, one could wind up with a dead MPU.
With the other methods, this wouldn't be an issue.
Perhaps someone could correct me if I'm wrong though.
I *didn't* write the firmware for this.
I provided the initial idea, options and hardware prototyping.

Thanks for the support!
Kevin

[Kevin Lightner]

Just a note that this project is a go, but I'm embarrassed to announce that the price will likely be considerably more.
With optical sensors at a $1 ea, DACs at $15 ea and so on, the parts alone are well over a hundred dollars each, not including the (4) circuit boards it uses.

I'm also only using gold-plated connectors, 1% resistors and other high quality parts.
But the labor is far beyond what I originally anticipated also.
About a thousand solder connections each.

So I may well sell less of them, but with labor and all the parts, there wouldn't be much profit if priced at $395 ea.
Therefore they'll probably go for $595 ea and every model will include MIDI in, out and thru.

On the plus side, it's more accurate than the stock keyboard, offers MIDI both ways, requires no soldering or special tools to install and should eliminate all contact cleaning problems.
With the price of a good 16 bit MIDI converter and repeat keyboard service calls, $595 isn't all that bad, is it?
It can even run off a single 9v battery for those wanting to make a keytar out of their Mini, but I discourage against carving up a good instrument.

Also I've made headway in research to retrofit various other synths with this same optical sensor system and things look good.
So sorry if I announced them at too optimistic a price, but at least I'm in production now and finally have a decent solution for Minimoog D contact problems and providing MIDI in (and out) with a minimum of trouble.

Thanks for listening.
Kevin

[Albdamned]

Kevin,

I am glad to hear this project is seeing the light of day.

Can the MIDI out be used in polyphony mode?

Thanks

Chris

[Kevin Lightner]

Can the MIDI out be used in polyphony mode?

Sorry no. At least not yet.
The MIDI code for it to play in mono was only just recently finished and is awaiting more testing.
But technically, it could send polyphonic MIDI.
The hardware is there, just not the software (yet.)

Thank you for your interest.
I'm working on the project and hope to one day have versions for several synths.
Wouldn't MIDI, no clean key contacts and say, an arpeggiator be cool in a Micro or Multimoog?

[ColorForm2113]

I would love have this for my micro! I get tired of cleaning contacts and calibrating my cheap little midi/cv converter. This is very exciting new, but unfortunately a little to pricey for me at the moment. But if you are still offering this further down the line I will definatetly sign up. Having an arppeggiator on my micro would just be fantastic!

[Voltor07]

I'm rarely on here anymore, but I can attest to Kevin's expertise in this, as he has told me details of this project via e-mail. I agree that there are multitudes of possibilities for this technology, and Kevin is definitely one of the best people to go to for anything MiniMoog related. I just wish I could afford a 61 key version of this project...sadly, it would cost as much as a Voyager XT...but THE TECHNOLOGY IS THERE!

[Kevin Lightner]

Just a quick note that MIDI out is now happening.
It's the 1st time I've ever played a MIDI keyboard FROM a model D's keyboard.
Mono, low-note priority (like the Mini), but musically works out very nicely this way.

Next: MIDI in and a way to change parameters (MIDI channels, priorities, etc) via the keyboard.

[Voltor07]

Good to hear the progress on this, Kevin! Sounds like a real winner for you! Especially since the economy is on the rise...

[suitandtieguy]

so does glide still work the same with this contact board?

if you crank the glide up, and play from one end to the other and release quickly, does the glide continue while you're not pressing a key or does it hold at the voltage it left at?