Polysex now open source hardware

panelonsynth4

Tubbutec Polysex is discontinued but we decided to make all the design files available to the public as open hardware. You can still purchase the PCBs in our shop.

The files include front panel mechanical drawings and print data, schematics and PCB layout, the mechanical stencil design and manuals.

If you use or modify this, please be so kind and leave a comment below. We also like pictures and videos 🙂

You can download the files as .ZIP here: Tubbutec Polysex design files.

Files are licensed under the CERN OHL v. 1.2.

Juno-66 update – now features custom scales

scales

Juno-66 firmware version 1.24 is released. Apart from the seven built in scales,  is now possible to upload a four custom scales using a program like Scala. Of course micro tuning is supported and you can have any number of notes per octave. Have a look at the user manual (chapter 10) for details.

In case you missed previous firmware updates, here are a few of the new features since the initial 1.00 release:

  • New school chord memory modes
  • Optional auto portamento in MONO B mode
  • Three voice mode
  • Looping mode, delay and polarity for ADSR

More infos about the Juno-66 upgrade on the Juno-66 product page.

 

 

SH-101 noise reduction mod

noisy

The Roland SH-101 while an awesome sounding synthesizer, unfortunately suffers from digital noise on its output. The main source of this noise is the current flowing through its DAC combined with bad grounding. The Tubbutec SH-1oh1 mod reduces the noise floor below that of the original (amongst a lot of other features), but noise is sometimes still an issue especially with bass sounds.
This is the instruction of an easy to perform – and reversible – modification that reduces the noise substantially, by about 10dB.

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Unison mode for Korg Poly-61

p61uni1

While the older brother of the Korg Poly-61, the Polysix, features a monophonic ‘Unison’ mode, the Poly-61 does not. The reason is most likely the fact, that the Poly-61 is DCO based, making the voice spread technology used in the Polysix Unison mode not possible.

It is however nevertheless desirable to add a monophonic mode to the Poly-61. Playing a monophonic synth is quite a different experience compared to a polyphonic one and if you have extended features such as not retriggering the envelope when playing legato, a whole new world of sound opens up.

If you install the Modysix mod you will have this feature build in, the only problem is: There is no ‘Unison’ button. You can select the unison mode using Midi, but it is actually quite simple to install an extra button and led.

p61unischem

You only need four parts and a little bit of wire: A push button, an led, a diode and a resistor. The push button can be any kind of button, the one I chose is what I had lying around, but you can probably find one that looks more like the original buttons.  The diode is a general purpose one, such as 1N4148. For the resistor choose a value of your liking. I found that the value of 470 Ohms used for the other leds in the Poly-61 gives too much brightness with modern leds (led technology has vastly improved in the last 30 years), so you might use a larger value such as 1k Ohms.

p61uni2

After installing the switch and led in the front panel, you can connect them to the panel board labelled KLM-482 – it is the one the ‘poly’,’chord’,.. buttons are mounted on. Pin3 and Pin9 in the schematic above refers to the pins on the connector on that panel. You can find +5V where I connected the resistor in the picture above. As you can see, I soldered the diode and resistor directly on the back of the PCB.

p61uni3

The last connection goes from the LED to Pin6 of IC3. It can be found on the processor board (the one with the battery).

When finished you can now use the unison mode on your Poly-61. Have fun!

Polysex example

A beautiful example of a Polysix modded with the Tubbutec Polysex mod:

http://polysix.info/

The author of this blog not only had a walnut chasis manufactured for his Polysix but also created a completly new overlay for the front panel which includes the Polysex mod.

I am sure Imploded View will have some new tracks soon and we will be able to listen to his Polysix 🙂