Improving Juno-6 and Juno-60 noise

Here are some investigations and improvements on the Juno-6 and Juno-60 noise performance. We looked at both, the original CPU as well as our Juno-66 upgrade

Both, the original CPU and Juno-66 create noise on the output. You can hear that by not playing anything on the keyboard, select SAW as input waveform (as this seems to reduce the VCA bleeding) and pull the gain all the way up.
This can be improved by adding additional filtering to the 5V supply. In case of the SH-101 for example which has a similar problem, an additional 10µF ceramic cap close to the CPU worked very well.

Now at least in the case of my Juno, the original CPU has actually a much louder noise ( I assume because it draws more current), as compare to Juno-66.
However, the noise is not focused on one frequency, but a braoder spectrum. This is due to jitter in the CPU code.

Juno-66 on the other hand, produces noise with a dominant frequency content and hence might be more audible – even though actually quieter.

To rectify this, I have created a firmware update that introduces additional jitter to broaden the spectrum a bit. Note, however that a good solution would of course eliminate the noise via supply rail filtering.

Noise of the original CPU, while a key is pressed the frequency is a bit different.

With the same settings: Juno-66 firmware 1.29. I press keys and change the portamento switch. Note, that this is already quieter than the original CPU

Same setting: Juno-66 firmware 1.3 – jitter is introduced

Soldering an additional 10uF capacitor between GND and 5V on the bottom of the board across the CPU supply pins, improved the noise even further.

You can find the 1.30 firmware on the updater site.

Midi for Kawai SX-210 with OrganDonor

Overview

The Kawai SX-210 version of OrganDonor offers the following features:

  • Fully polyphonic midi input for all 61 Notes
  • Optional learn button to set midi channel.

Installation

The installation is relatively simple, but does require basic soldering skills. You will need to drill a hole for the midi socket.
Installation instructions can be found in this PDF.

User guide

Setting midi channel and keyboard offset

If the optional learn button is installed, it can be used to quickly change the midi receive channel of organDonor.

Connect midi out of a computer or keyboard to midi in of organDonor. Make sure not to send any notes.
Press the learn button and while it is pressed send a midi note on any midi channel. organDonor will set this note as the lowest note of the synthesizer and use its midi channel. These settings are saved.

Playing notes

Send midi notes on the configured midi channel (see above)

More configuration

Alternatively you may configure a lot of parameters using our organDonor configurator.
We recommend using the Kawai SX-210 config file as starting point
1.) Save the file on your hard drive via right click -> save as
2.) in the configurator press “Load configuration” and select the file

Korg Mini Pops 45 MIDI with uniPulse

This manual shows how to install uniPulse in a Korg Mini Pops 45 and trigger all 10 instruments via Midi.

The installation is fairly simple and only requires soldering a few wires and parts into place, as well as drilling a hole for the midi socket.

Trigger connections

Here we see the 10 trigger points for the various instruments. These are trigger outputs P1-P10 from uniPulse directly soldered to the trigger points.

In order to power the uniPulse you just need to solder the brown (V+) and red (GND) wires to the electrolytic capacitor shown in the picture.

Installing the midi socket

Installing the midi socket is simple. A drill guide is included in the kit. Any location is fine, we chose to install the socket next to the audio sockets.

Config file upload

After installing uniPulse, turn on the machine and make sure the LED on the uniPulse is turned on. This means it has power and is running.
Connect midi and use the config tool to upload the following configuration.

Config file (right click, save as)

have fun!

 

Midi for Moog Opus 3 – OrganDonor

Overview

The Opus 3 version of organDonor offers the following features:

  • Fully polyphonic midi input for all notes
  • Optional learn button to set midi channel.

Installation

The installation is relatively simple, but does require basic soldering skills. You will need to drill a hole for the midi socket.
Installation instructions can be found in this PDF.

User guide

Setting midi channel and keyboard offset

If the optional learn button is installed, it can be used to quickly change the midi receive channel of organDonor.

Connect midi out of a computer or keyboard to midi in of organDonor. Make sure not to send any notes.
Press the learn button and while it is pressed send a midi note on any midi channel. organDonor will set this note as the lowest note of the synthesizer and use its midi channel. These settings are saved.

Playing notes

Send midi notes on the configured midi channel (see above)

More configuration

Alternatively you may configure a lot of parameters using our organDonor configurator.
We recommend using the Moog Opus 3 config file as starting point
1.) Save the file on your hard drive via right click -> save as
2.) in the configurator press “Load configuration” and select the file

How to install MIDI jacks the proper way

Introduction

When retrofitting midi to old gear using our kits, often holes for the midi sockets need to be drilled. This guide is how we do it and shows a clean, easy way using a hole punch.

Stuff you need:

  • Drill Aid
  • Center Punch
  • 2mm drill
  • 3.2mm drill
  • 4mm drill
  • 6mm drill
  • 8mm drill
  • Screw hole-punch 15.2mm
  • Box wrench 13mm
  • Electric drill

 

  1. Attach drill aid
  2. Punch the center holes

3. Remove drill aid

4. Drill 2mm pilot holes

5. Use 3.2mm drill

6. Use 4mm drill

7. Use 6mm drill

8. Use 8mm drill

9. Insert screw and skirt of the screw hole-punch

10.Attach the cutting part of the screw hole-punch

11.Use the box wrench, clockwise

12. Result

13. Install MIDI jack

That’s all. Have fun.

 

Midi for Siel Orchestra

Overview

The Siel Orchestra version of OrganDonor offers the following features:

  • Fully polyphonic midi input for all 49 notes
  • Optional learn button to set midi channel.

Installation

The installation is relatively simple, but does require basic soldering skills. You will need to drill a hole for the midi socket.
Installation instructions can be found in this PDF.

User guide

Setting midi channel and keyboard offset

If the optional learn button is installed, it can be used to quickly change the midi receive channel of organDonor.

Connect midi out of a computer or keyboard to midi in of organDonor. Make sure not to send any notes.
Press the learn button and while it is pressed send a midi note on any midi channel. organDonor will set this note as the lowest note of the synthesizer and use its midi channel. These settings are saved.

Playing notes

Send midi notes on the configured midi channel (see above)
By default, the channel is midi channel 1

More configuration

Alternatively you may configure a lot of parameters using our organDonor configurator.
We recommend using the Siel Orchestra config file as starting point
1.) Save the file on your hard drive via right click -> save as
2.) in the configurator press “Load configuration” and select the file

Midi for Korg Lambda using organDonor

Overview

The Korg Lambda version of OrganDonor offers the following features:

  • Fully polyphonic midi input for all 48 notes
  • Optional learn button to set midi channel.

Installation

The installation is relatively simple, but does require basic soldering skills. You will need to drill a hole for the midi socket.
Installation instructions can be found in this PDF.

User guide

Setting midi channel and keyboard offset

If the optional learn button is installed, it can be used to quickly change the midi receive channel of organDonor.

Connect midi out of a computer or keyboard to midi in of organDonor. Make sure not to send any notes.
Press the learn button and while it is pressed send a midi note on any midi channel. organDonor will set this note as the lowest note of the synthesizer and use its midi channel. These settings are saved.

Playing notes

Send midi notes on the configured midi channel (see above)
By default, this is midi channel 1.

More configuration

Alternatively you may configure a lot of parameters using our organDonor configurator.
We recommend using the Korg Lambda config file as starting point
1.) Save the file on your hard drive via right click -> save as
2.) in the configurator press “Load configuration” and select the file

Midi for Roland RS-505 with organDonor

Overview

The Roland RS-505 version of OrganDonor offers the following features:

  • Fully polyphonic midi input for all 49 synthesizer notes and 24 bass notes
  • Bass section on a separate midi channel
  • Optionally control the register switches of the synthesizer section
  • Optional learn button to set midi channel.

Installation

The installation is relatively simple, but does require basic soldering skills. You will need to drill a hole for the midi socket.
Installation instructions can be found in this PDF.

User guide

Setting midi channel and keyboard offset

If the optional learn button is installed, it can be used to quickly change the midi receive channel of organDonor.

Connect midi out of a computer or keyboard to midi in of organDonor. Make sure not to send any notes.
Press the learn button and while it is pressed send a midi note on any midi channel. organDonor will set this note as the lowest note of the synthesizer and use its midi channel. These settings are saved.

Playing notes

Send midi notes on the configured midi channel (see above)
By default, the synthesizer section is on midi channel 1, the bass section on channel 2.

More configuration

Alternatively you may configure a lot of parameters using our organDonor configurator.
We recommend using the Roland RS-505 config file as starting point
1.) Save the file on your hard drive via right click -> save as
2.) in the configurator press “Load configuration” and select the file

Midi for Roland RS-09 with OrganDonor

Overview

The Roland RS-09 version of OrganDonor offers the following features:

  • Fully polyphonic midi input for all 44 Notes
  • Optional learn button to set midi channel.

Installation

The installation is relatively simple, but does require basic soldering skills. You will need to drill a hole for the midi socket.
Installation instructions can be found in this PDF.

User guide

Setting midi channel and keyboard offset

If the optional learn button is installed, it can be used to quickly change the midi receive channel of organDonor.

Connect midi out of a computer or keyboard to midi in of organDonor. Make sure not to send any notes.
Press the learn button and while it is pressed send a midi note on any midi channel. organDonor will set this note as the lowest note of the synthesizer and use its midi channel. These settings are saved.

Playing notes

Send midi notes on the configured midi channel (see above)

More configuration

Alternatively you may configure a lot of parameters using our organDonor configurator.
We recommend using the Roland RS-09 config file as starting point
1.) Save the file on your hard drive via right click -> save as
2.) in the configurator press “Load configuration” and select the file