Build Pictures 2025

analogmonster · Joined: May 30, 2011 Posts: 90 Location: Germany

Hello everyone,

I was asked to build this for integrating an analog ratcheting sequencer into a studio’s MIDI equipment setup by a friend, the author of the Formant MSS2000 book.

So I decided to build this as a set of eight independent microcontroller controlled CV/GATE/CLOCK to MIDI converters.
Each converter consists of a pair of inputs (CV and CLOCK) and a corresponding CLOCK display LED.

At the top of the module you find three switches (again with indicator LEDs, because I just love Mr. Green

LEDs) to select one of eight programs the module runs with.
Currently implemented is "Program 0" which was requested by my friend, but further functions are in development.

Fun Wink

Here a video which shows the module converting an analog sequence with ratcheting into MIDI based ratcheting for my MIDI controlled Oberheim SEM clone as a feasibility test:

https://youtu.be/zcSQnTrbIEA?si=22iIfI8ag4w-dPT-

CV2MIDI_3dview.jpg

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kkissinger

The Peasant

analogmonster · Joined: May 30, 2011 Posts: 90 Location: Germany

analogmonster · Joined: May 30, 2011 Posts: 90 Location: Germany

Hello everyone,

my new converter toy reached the next level. "Program 1" is implemented. This makes the device being a stand-alone MIDI sequencer.

CLK1 serves as master clock. CV1 to CV8 are iterated. Unconnected CVs are interpreted as 0V / C0 note.

Here the new fun video: https://www.youtube.com/watch?v=OrOuQNHJ9Yw

CV2MIDI_prog1.jpg

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analogmonster · Joined: May 30, 2011 Posts: 90 Location: Germany

Fresh from the playground: 2 more sequencer modes as "Program 2" and "Program 3" implemented: "Moving Backwards" and "Knight Rider Mode" Mr. Green

See YouTube Demo 3!

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The Peasant · Posted: Thu Jul 10, 2025 8:36 pm Post subject:

Hi again everyone,

I finally was able to make a recording of the tube synth modules, including the new VCF design which is still only on breadboard. Once I get that module built I will work on making an actual video of everything so far.

To make the recording I just set up a sequence and let it play while I changed settings. I also added some reverb, since everything sounds better with reverb!

The first part is just the VCO module through the VCA, then the noise module is added for a while, then the VCF is included for the last part. Enjoy!

Take care,
Doug

alltubepath.flac

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Download (listen)

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analogmonster · Joined: May 30, 2011 Posts: 90 Location: Germany

My first microcontroller based module, an 8 channel MIDI2CV/GATE - interface (UCVM) from 2004 did not boot any more. Reason was a dead ISP connector.

So I did what I was afraid of, I opened it after several years and entered the guts.

Enjoy the pictures.

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UCVM control

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UCVM voices

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ucvm_repair_04.jpg

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PHOBoS · Posted: Fri Jul 11, 2025 12:11 pm Post subject:

some lovely looking stuff in here. Very Happy

I might not be building anything myself at the moment but I am watching from the sidelines.

kkissinger

Years ago, when I began expanding my synthesizer system, I needed to add an additional power supply and the associated wiring in the new cabinet. Wanting to ensure reliability, I chose to use larger 18 AWG wiring and robust TE connectors. This became the new standard for all added modules, and I built distribution cables to supply power accordingly.

Over time, however, I became less satisfied with the loose cable runs — they weren’t as secure as I’d like, were vulnerable to vibration, and didn’t look particularly neat. Still, redesigning the bus system was one of those "I’ll get around to it later" projects.

As I started adding microprocessor-based modules, I wanted to integrate a CAN bus to support global inter-module functions. That provided the push I needed. I realized I could use my 3D printer to create custom channel segments that support both the existing TE power connectors and new Molex CAN connectors.

The snap-in feature of the TE connectors made it relatively easy to design 3D-printed mounting holes to accommodate them securely. Since my printer's bed is only around 12" wide, I chose to print 3" channel segments (matching the Aries 3" module width), then arrange them end-to-end to form a continuous channel along the cabinet.

This is still a work in progress, but I recently completed the first cabinet channel and took a photo to show a before-and-after comparison — the top cabinet still has the original loose power cables, while the bottom cabinet uses the new channel. I’ve also included a picture of a few channel segments as they come off the 3D printer. For efficiency, I print them three at a time per batch.

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Power supply buss installation in progress to compare old and new

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Channel pieces from the 3d printer

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Grumble · Posted: Fri Jul 18, 2025 12:36 pm Post subject:

I've made what I call a DRONER, It's a standallone module around an Arduino UNO, programmed as a native midi device ( google HIDUINO) for sending Midi over USB.
You can choose a note, change velocity and pitch in real time.
The noteOn is sent when the ON button is pressed while the noteOff is sent when the OFF button is pressed.
When noteOn is active, I can change Pitch with a rotary encoder, and the Velocity can be set with the potentiometer.

https://youtube.com/watch?v=zpr1dhiscE4&si=2Lu5zHIT3lCUMhMP

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analogmonster · Joined: May 30, 2011 Posts: 90 Location: Germany

@Kevin and @Grumble, beside the cool synth stuff you build there are also some nice 3d printed components here! thumb up

kkissinger

kkissinger · Posted: Sat Jul 19, 2025 2:21 pm Post subject:

PHOBoS · Posted: Sun Jul 20, 2025 10:23 am Post subject:

Grumble · Posted: Sun Jul 20, 2025 1:28 pm Post subject:

Thanks!
I wasn't happy with the software and have been tweaking today.
Much better functionality now.

The Peasant · Posted: Sun Aug 10, 2025 8:57 pm Post subject:

I have completed the VCF module, 14 tubes in this one. Working on a video now.

Take care,
Doug

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kkissinger · Posted: Tue Aug 12, 2025 5:02 am Post subject:

Grumble · Posted: Tue Aug 12, 2025 7:21 am Post subject:

Great, I love tube stuff.
Although I learned electronics during the tube periode/start of transistor era (think oc71 etc.) I never build anything using tubes….

kkissinger

Well, I don't have a photo for this fix. However, I enjoy finding ways to make vintage modules work "better than new".

I recently solved a long-standing quirk in my vintage Aries AR-334 sequencer. When it received simultaneous clock and reset signals, it would jump to step #2 instead of starting cleanly at step #1.

Digging into the circuit, I found that the clock-in path included a 0.1 µF capacitor to ground in parallel with a 39 kΩ resistor. This RC combination slightly delayed the clock pulse compared to the reset pulse. When clock and reset arrived at the same time, the reset would trigger first, then the delayed clock edge would immediately advance the sequencer to the second step.

The fix was straightforward: I removed the 0.1 µF capacitor, leaving the 39 kΩ resistor in place. With the capacitor gone, the clock signal is no longer delayed, and the sequencer now resets and starts properly on step #1, matching the behavior of my other sequencers and clock dividers.

This will allow me to fully integrate the vintage Aries sequencer with my Klee and other sequencers (particularly Wren sequencers and the Elektron Octatrack sequencer).

mosc · Posted: Fri Aug 15, 2025 11:31 am Post subject:

I second the request hear a 14 tube filter Cool

Cynosure · Posted: Today, at 7:11 am Post subject:

It's not a synth, but it makes noise.

My daughter was trying to make a little animal with buttons out of paper, but was having difficulty with the buttons. I suggested wood as a better option. Since I had to be involved anyway to cut the wood, I offered to make the buttons beep when pressed.

My daughter drew the shape and painted it. I cut it out and added the electronics.

I kept it as simple as possible. It is four 40106 oscillators with fixed resistors values for different pitches, and a single amplifier chip (LM386), all running off a 9V battery.

https://www.youtube.com/shorts/Z-s8PWctHC4

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Beeping animal button toy

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