Building a preset box

System 55 • System 35 • Model 15
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noddyspuncture
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Building a preset box

Post by noddyspuncture » Mon Dec 28, 2020 7:35 pm

Hi folks,

I'm currently building a 'preset box' based on the 1969 'Jazz In The Garden' designs for my Modular Moog's.
I'd like to share photos - pity the board doesn't allow it anymore.

:(

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analogmonster
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Re: Building a preset box

Post by analogmonster » Tue Dec 29, 2020 4:58 am

How does it work? A selectable group of CVs connected to modules, especially like sequential switches etc.?

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noddyspuncture
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Re: Building a preset box

Post by noddyspuncture » Tue Dec 29, 2020 4:18 pm

analogmonster wrote: Tue Dec 29, 2020 4:58 am How does it work? A selectable group of CVs connected to modules, especially like sequential switches etc.?
No - nothing like that.
There is what you could call a 'CV feed' to the node of the osc controllers for the fine tuning and also the node of the filter for fixed control voltage level - but the rest of it basically "custom interfaces" into the individual modules - which also need individually customising.

It's a massive project. :shock:


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noddyspuncture
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Re: Building a preset box

Post by noddyspuncture » Sat Jan 02, 2021 3:45 pm

analogmonster wrote: Wed Dec 30, 2020 6:19 am Ok. What are the voltage sources?
All voltage sources are derived from within the preset box itself... in fact, each card provides different ones via the settings. Other variables, such as all the EG settings, and the resonance actually interface into each module directly. The CP3 mixer level settings are done with vactrols and lightbulbs originally... but I'm using high brightness LED's there.

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analogmonster
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Re: Building a preset box

Post by analogmonster » Sun Jan 03, 2021 7:10 am

I'd love to see pictures (and schematics of course). Why don't you run a web site?

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noddyspuncture
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Re: Building a preset box

Post by noddyspuncture » Sun Jan 03, 2021 8:03 am

analogmonster wrote: Sun Jan 03, 2021 7:10 am I'd love to see pictures (and schematics of course). Why don't you run a web site?
If I could I would post photos of my progress but as I noted earlier, this forum doesn't allow it.

I have all the schematics and drawings and notes - they also include schematics of the revised 901A&B controller & oscillator which Bob redesigned for Emerson, taking the expo converter from the controller and putting it into the oscillator as part of the overall redesign. A lot like how the 921's ended up being configured - maybe that was his R&D for the new oscillator although the 921's are a completely different animal. I actually do need to build another controller and oscillator for my System 15 to utilise this 'preset box' so I've decided to build those 'revised' 901's.

Unfortunately I can't share and schematics as I was given them in confidence. :!:

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analogmonster
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Re: Building a preset box

Post by analogmonster » Mon Jan 04, 2021 4:54 am

noddyspuncture wrote: Sun Jan 03, 2021 8:03 am If I could I would post photos of my progress but as I noted earlier, this forum doesn't allow it.
I know. If you mail me some photos with some comments I can put it on my web site and post the link.
noddyspuncture wrote: Sun Jan 03, 2021 8:03 am Unfortunately I can't share and schematics as I was given them in confidence. :!:
Ok, but are they still in production or under copyright protection? I think a lot of collectors would love to see the modified schematics and the special modules you mentioned.

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noddyspuncture
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Re: Building a preset box

Post by noddyspuncture » Tue Jan 05, 2021 8:32 am

analogmonster wrote: Mon Jan 04, 2021 4:54 am Ok, but are they still in production or under copyright protection?
These are basically copies of Emerson's Modular service manual with notes by Bob as he worked on it over the years, I suppose he also added the drawings for the new module modifications etc... Like I said, I was given them in confidence and asked not to share them so I cannot really go back on my promise.

I've built a 921A circuit (I'm still waiting for the enclosure) as the preset box requires A/B/A/B/A/B configuration - and also decided to add a '905 reverb' into the system. I do have a video of those which I made, also demonstrating the footage switching and regen switching.
Here's the link:

https://www.youtube.com/watch?v=E67oy9D ... yspuncture

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analogmonster
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Re: Building a preset box

Post by analogmonster » Wed Jan 06, 2021 3:42 am

Cool reverb :)

May I ask another question? Did Bob keep the CA3019 based expo solution of the 901A when he transferred this to the 901B oscillator or did he change this to something like the heated transistor array solution like in the Mini then?

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noddyspuncture
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Re: Building a preset box

Post by noddyspuncture » Wed Jan 06, 2021 7:55 am

analogmonster wrote: Wed Jan 06, 2021 3:42 am Cool reverb :)

May I ask another question? Did Bob keep the CA3019 based expo solution of the 901A when he transferred this to the 901B oscillator or did he change this to something like the heated transistor array solution like in the Mini then?
No that diode array is bypassed - there is a tempco in there though which I've had to source. Building these two 901's will be the last project for the system 15.

I already built a 901A and a 901B as per the original ccts from the service manual for my R.A.Modular and both are working wonderfully. :D

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ummagumma
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Re: Building a preset box

Post by ummagumma » Thu Jan 07, 2021 2:07 pm

that is a pretty fascinating project, looking forward to hearing/seeing the final thing in action!

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noddyspuncture
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Re: Building a preset box

Post by noddyspuncture » Wed Jan 20, 2021 6:37 pm

I just finished another part of the project today...

It's the 'latching' control unit which I have just finished putting together for the Moog Modular preset box I am building.

It will have eleven control lines coming in from the push-button unit. 10 outgoing lines will go to the 10 preset cards and will enable each card.

The 11th will go nowhere... it will be an 'over-ride' or panel/manual preset, in effect isolating the box from the Modular, basically so no card is active. I just hooked up 2 LED's to test... :D

Here's the link... https://www.youtube.com/watch?v=oNS1sQt ... e=youtu.be

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noddyspuncture
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Re: Building a preset box

Post by noddyspuncture » Mon Jan 25, 2021 4:04 pm

I have another video of some more progress with the Modular preset box I am building.

On this video I'm doing a dual test - testing both the preset box controller, now installed in the case and also the power switching circuit on the breadboard to check if it will actually work with the controller.

It's a copy of Bob Moog's circuit which he used on Emo's preset box and each preset card will have one on it.

Each card is applied with +12 & -6 volts which will feed this on-board circuit. The output of the switching circuit - when enabled - will then power the rest of the card and the preset controller enables and disables them depending on which button is pressed.

I'm monitoring the outputs of the circuit on my meter and switching to what would be preset 1 (green LED) which has it's control line going to the breadboard and then I am switching away to preset 11 (red LED) which will be the 'defeat' button and will basically bypass the preset box completely and make the Modular behave as there were no preset box connected.

It all seems to be working nicely, first time - which is good... :D

So here's the link...
https://www.youtube.com/watch?v=zGQkJkg ... yspuncture

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