dreadbox DYSPHONIA Eurorack and Desktop Synthesizer DIY Kit User Manual

dreadbox DYSPHONIA Eurorack and Desktop Synthesizer DIY Kit

Construction

BEFORE YOU GET STARTED
Before you start the construction of this DIY project, make sure you have basic soldering skills and that you can identify the electronic components. If it is your first time soldering, there are several tutorials on YouTube that can help you.
It would be easier and helpful for you to work on a big desk, so as to have plenty of space to work on. Also a room with an open window would be perfect while you soldering.
Before you start the soldering process, make sure you have all the components needed and noted in the BILL OF MATERIALS SECTION. Please note that we might have added more components than needed or less (hopefully not). It would be very helpful if you count all the components before starting the project (but without removing these from their bags).

What’s in the box?

In the box you should find the following items:

• The Bottom board, which is pre-assembled and tested in-house (though you will still need to solder the ribbon header and tune it)
• The Top board
• The aluminum panel
• The power board
• The components bag
• A DIN5 (MIDI) to 3,5mm cable adapter (specs as suggested from MIDI.org)
• A ribbon cable for modular use (not shown in the picture)

Components

In the bag we’ve included all of the hardware parts

• 46 x 3,5mm stereo jack
• 13 x 100KB plastic rotary pot
• 8 x 10KB slider pot
• 2 x pushbutton with red LED
• 3 x female 20 pin connector headers
• 1 x female 10 pin connector header
• 1 x male 10pin ribbon connector header
• 1 x USB jack
• 8 x M3 Bolts with HEX head
• 6 x M3 bolts with Philips head
• 6 x M3 plastic spacer 16mm length
• 12 x M3 plastic spacer 11mm length
• 2 x M3 metal spacer 10mm length
• 2 x M3 washer 1mm heigh

Tools you will use

The following tools are required for this assembly, but they are not included in the KIT

• Digital multimeter
• Soldering wire(0.7mm and 1.5mm)
• Soldering Iron
• Cutter
• Pliers

Preparation of the bottom board

For this step you will need:

• The bottom board
• A Soldering iron
• 0.7mm solder wire
• A Cutter
• The 10pin ribbon male header

Solder the ribbon header to the bottom side of the board as shown in the pictures

Then, cut the excess wires from the pre-assembled trimmers and remove the extra PCB from the top and bottom side of the board.

Preparation of the power board

For this step you will need:

• The 0.7 solder wire + a soldering iron
• The USB jack
• The 10pin female header

Solder the USB jack and the header, as shown in the pictures.
You can also use this board as a generic modular power supply. Max supplied current is 200mA@+12V and 80mA@-12V. In order to do this, you need to solder a 16pin male ribbon header (not included in the kit), instead of the 10 pin female.
Pin “1” is marked with a small circle at the bottom right.

Preparation of the top board

Start by removing the excess PCB from the board

Locate and place the 3.5mm jacks on the board

Then solder these by using the 1.5mm wire

Next, locate the two push buttons.
WARNING! They have a polarity that needs to be respected! If not placed correctly they will be damaged and removing them is a challenging task!

Check their bottom side. The “+” sign should match the square pad on the PCB.
Another tip on how to place them correctly is : The guide on the top should match the small hole on the PCB, and the long middle lead should match the cycle pad.

Once you are sure regarding their orientation, push them firmly down to their position. WARNING!: If the button is not pushed correctly, it will touch the aluminum panel and this will not allow it to rest to it’s OFF position – or it will not be able to be aligned correctly to the whole of the panel.

The next step is to solder the slider potentiometers.
Locate all 8 sliders and place them on the PCB.

The proper way to solder the sliders straight, is to solder the top pin from the top side of the PCB. Then turn the PCB upside down and reflow the rest pins. Make sure they are placed correctly.

Make sure you have not set the soldering iron above 350 degrees. Also do not heat each slider pin for more than 5 sec each time.
Do not try to adjust the slider’s lever while it is hot.

Finally, place the rotary potentiometers on the PCB.

WARNING!: Make sure they are perfectly straight! Otherwise they will not be aligned correctly to their corresponding hole on the panel!

Make sure you have not set the soldering iron above 350 degrees. Also do not heat each pot pin for more than 5 sec each time.
Do not try to adjust the pot’s lever while it is hot.

Connection of the top and bottom boards

In this step we will connect the two boards and solder their connecting PIN headers.

Locate the 3x female 20pin headers. Place them as shown in the pictures. Make sure they are firmly attached to their position.

Next, locate the following parts:

• 2 x M3 HEX bolt
• 2 x M3 10mm metal spacer
• 2 x M3 washer

These will be the base for the power board.
If you are not going to use it with the USB power board, you should skip this step.

Place them as shown in the pictures:

• Hex bolt on the top side of the PCB, then place the washer to the other side and then add the metal spacer. Bolt them firmly.

Now prepare the top board’s spacer structure, so as to be able to connect the panel and the bottom board. Find and place, as shown in the picture, the 12 pcs x 11mm plastic spacers.

Connect the Top and Bottom board as shown in the pictures.

Locate the 6pcs X 15mm plastic spacers. Then turn the assembly upside down and lock the two boards by attaching the spacers as shown in the picture.

Finally, flip the assembly and solder with the 3 pin headers using the 0.7mm wire.

OPTIONAL
Remove R40, if you want a long delay time. Note though that as the repeats get longer, their signal becomes very dirty.

Finalize the Module

Place the aluminum panel as shown in the picture.
Use the 6pcs x Hex bolts to attach it into place.

Next, attach the power board as shown in the picture. If you are going to use it in a modular case, skip this step.

By using a cutter, you can shorten the 16mm plastic spacer by cutting out the threaded part.

The module is completed and you should now move on to the tuning procedure.

Check, Tune and Calibrate

Check the Assembled Module

When the assembly of the module is complete, you should check that everything works. The following steps will guide you through this process:

1. Power the unit. You should see a light sequence on the SET and TYPE buttons. After the sequence stops, the TYPE LED should blink at the LFO rate (that is determined by the MOD RATE slider). Connect a MIDI keyboard via the MIDI to 3.5mm adapter, that is provided in the kit. Press the SET button. The LED will lit. Press any key on the MIDI keyboard and then press SET again. Now your MIDI converter is set to your MIDI keyboard’s channel.
   If your unit does not power up for the first time , do the following:

   • Unscrew the small power board.

   • Plug the power board alone in the USB supply.

   • While it’s powered, connect it to the module.
     After this procedure, your unit should power up normally.
     If not, check the following:

   • Either your USB cable or power adapter are of a bad quality.

   • Your adapter cannot provide enough mA

   • You have done something wrong, during the assemble.

2. Do the following connections:

   • CV OUT (placed in the MIDI to CV section) to OSCILLATOR CV IN (both CV IN are identical).
   • SAW to a monitor or somewhere that you can get signal. WARNING!: this is a very high signal level!
   • Adjust the OSCILLATOR TUNE at 0% and the FINE at 50%. Now observe the SAW signal. Play some notes on the MIDI keyboard and make sure that the pitch changes. Play with the TUNE slider and FINE knob and observe the pitch changes. Then check the TRI and SQU outputs. Finally check the NOISE, which will not respond to the change of the pitch.

3. Remove the CV OUT to OSCILLATOR CV IN connection and then patch:

   • MOD OUT to OSCILLATOR CV IN.
   • Connect the SAW OUT to your monitor.
   • Adjust the OSCILLATOR TUNE and FINE at 50%, MOD RATE 50%, MOD LVL at max. Observe the change of the pitch. Move the MOD RATE slider and confirm that it works.
   • Then press the TYPE button once. Move RATE up and down and set it at 50%. Observe the random LFO.
   • Press the TYPE button again. Move RATE up and down and set it at 50%. Press any key on the MIDI keyboard. Observe the envelope modulation.
   • Press the TYPE button again. Move the Modulation wheel of the MIDI keyboard. Observe the change of the pitch.

4. Remove the MOD OUT from the OSCILLATOR CV IN connection and then patch:

   • The ENV OUT to the OSCILLATOR CV IN.
   • The G OUT (placed in the MIDI to CV section) to the ENV TRIG IN.
   • Set the FALL at 50% and the LVL at max. Press any key on the MIDI keyboard and observe the change of the pitch.

5. Remove the ENV OUT from the OSCILLATOR CV IN and the G OUT from the ENV TRIG IN and then Patch:

   • The LFO OUT to the OSCILLATOR CV IN.
   • Set the LFO RATE at 50% and the LVL at max and observe the pitch changes.
   • Then set the MOD with the TYPE button on the LFO mode and patch the MOD OUT to the LFO CV. Adjust the MOD RATE at 50% and observe the change of the pitch.

6. Remove all patches and connections so that the panel is clear. Now connect and set:

   • the SAW to the LPF IN
   • the LPF OUT to the MIXER IN (you can choose any channel)
   • Connect the MIXER OUT to a monitor
   • Adjust:
   • OSCILLATOR TUNE and FINE at 50%
   • LPF CUT at max
   • LPF RES at min
   • MIXER IN (all channels) at max
   • MIXER LVL at max and observe the change of the pitch.
   • Play with the CUT and RESON controls and observe the changes.
   • Use all MIXER channels and make sure the signal passes through.
   • Play with the MIXER level and make sure it works. Please note that at 50% knob travel, the mixer level is almost off and at 0% the signal is inverted.

7. Remove the SAW from the LPF IN and the LPF OUT from the MIXER IN.
   Now connect and set:

   • SAW to 12DB IN (any channel)

   • 12DB LP to the monitor

   • Adjust:

   • OSCILLATOR TUNE and FINE at 50%

   • 12DB CUT at max

   • 12DB RES at min
     Observe the SAW signal.

   • Play with the CUT and RESON controls and observe the changes.

   • Use all 12DB IN channels and make sure that the signal passes through.

   • Also connect the monitor to the BP and HP. Play with the CUT and RESON controls again and make sure that the signal passes through.

8. Disconnect the monitor from the 12DB. Now connect:

   • 12DB LP to ECHO IN
   • ECHO OUT to a monitor
   • Adjust the ECHO FEED, TIME and MIX at 50%
     Observe the sound and move the CUT slider from max to min, so that the echo can be easily heard.

9. Remove all patch cables. Now connect:

   • OSCILLATOR SQU to a monitor
   • LFO OUT to OSCILLATOR PW
   • Adjust the TUNE and FINE at 50%
   • LFO RATE at 50%
   • LFO LVL at max
     Observe the PWM modulation of the square wave.

10. Remove all patch cables and now connect:

    • OSCILLATOR SQU to VCA (1) IN (any channel)

    • VCA (1) OUT to a monitor

    • LFO OUT to VCA (1) CV

    • LFO RATE at 50%

    • LFO LVL at max
      Observe the signal open and closing at the LFO rate.

    • Check both IN channels on the VCA (1)

11. Remove all patch cables and now connect:

    • OSCILLATOR SQU to VCA (2) IN

    • VCA (2) OUT to a monitor

    • LFO OUT to VCA (2) CV

    • LFO RATE at 50%

    • LFO LVL at max

    • VCA (2) INIT at 50%
      Observe the signal’s opening and closing to the LFO rate.

    • Remove the LFO OUT from VCA(2) CV and set INIT at max.
      Observe a constant signal.

    • Follow the exact above process for VCA(3)

12. Remove all patch cables and now connect:

    • OSCILLATOR SQU to a monitor
    • LFO OUT to MULTI IN
    • MULTI OUT (any channel) to OSCILLATOR CV IN and observe the change of the pitch.
    • Check all MULTI OUT channels

The Check is now complete!

Tuning and Calibrating the Module

After the assembly is complete and checked, it’s time to calibrate Dysphonia.
To measure any of the points below do the following:
Open your multimeter and set it to DC voltage mode. The black probe (ground) should be connected to the ground via (1) and the red one to the measured element. You need at least a 4 digit multimeter for an accurate measurement. You can use a multimeter with less than 4 digits, but your measurements won’t be accurate.

To get started, connect a MIDI keyboard by using the supplied DIN5 to 3.5mm jack adapter.
Press SET twice and set MOD Type to EG. Then measure the MOD measuring point (2) and adjust the MOD_OFFSET trimmer so as the multimeter shows 0.000 Volts.
Then it’s time to calibrate the CV OUT. Play the lowest note on the MIDI keyboard C0, measure the CV (3) point and with the CV_OFFSET trimmer adjust it to 0,000 Volts.
Play again the highest note C9 and with the CV_SCALE trimmer adjust so as it is 9,000 Volts. After setting this up, play all C notes from C9 to C0 and the multimeter should show from 9 Volts down to 0 Volts 1 V/ oct. If not adjust accordingly.
Then there is the NOISE_LVL trimmer, which adjusts the level of the noise. There is not a specific way to adjust this level because it depends on the user’s taste. We suggest that the level of the Noise should be almost the same as the one of the Triangle Oscillator OUT and that it doesn’t peak or create any clipping artifacts.
Proceed to the Oscillator tuning. To do so, the MIDI CV OUT needs to be patched to the CV input of the Oscillator.
Set the TUNE slider at 0% and FINE TUNE pot at 50%. Connect one of the wave outputs to a tuner and press the A2 note on the keyboard.
Adjust the TUNE trimmer, so as the tuner shows the A note at 110 Hz. Then play the A5 note and adjust the SCALE trimmer, so as the tuner shows the A again but at 880 Hz.
Repeat this process until both A are perfectly in tune. Then press all A notes from A0 to A9 and check the tuning. A small amount of drift, especially on the higher frequencies, is expected, with maximum deviation to be around 5-10 cents.

1. GROUND (any similar looking hole without a connecting line is a ground)
2. MOD point
3. CV point

User’s Manual

Oscillator

This is an analog oscillator with multiple wave shapes consists of:

• Four dedicated outputs: Square Wave, Sawtooth, Triangle and Noise.
• Two CV inputs for pitch control at 1V/oct.
• A PW CV input for the Square wave.
• A Tune slider for Coarse tuning.
• A Fine tune potentiometer for fine tuning.

The output level of the waveforms is at +/-5V an the CV IN accepts +/-10V.

VCA

The VCA section consists of:

• One VCA with two inputs, a mixed output and a VCA CV. This is an exponential curved VCA and it is mostly suitable for audio signals.
  Works best with 0-5V CV control and expects +/-5V IN signals.

• Two VCAs with an input, an output, a potentiometer to control the initial VCA value and a VCA CV. These are linear VCAs, and even though they can handle any signal (CV or audio), they are more suitable for CV signals because of their linearity.
  They expect a CV signal of +/-5V. With the INIT potentiometer at max and no CV, unity gain is achieved.

Multiple (MULTI)

The Multiple section is a passive multiple that consists of:
One input and three outputs.
The multiple is only suitable for CV outs and not for inputs. That means that you can send an output (for example the LFO OUT) and then use the OUTs of the Multiple to send it to various Inputs. But you CANNOT connect 2 OUT signals there.

Mixer

The Mixer section consists of:

• Three inputs with separate level control.
• One output with positive and inverted level.

The LVL knob closes the signal at about 50% of its value. Note that it will never be completely off, but there will always be a minimal amount of signal passing through. When the LVL knob is at 0%, the signal is at full level but inverted. When is set at max, it is at its full level again, but not inverted.

MIDI to CV/GATE

The MIDI section consists of:

• TRS TYPE A MIDI input.
• A SET Button for changing the MIDI channel, which can be used as SHIFT button (See below). Press SET button once, as long as the SET button is lit, OMNI mode is engaged.

Now press a key on your MIDI controller. Press SET button again to lock the MIDI channel to the last channel played.

• 1V/oct CV output.
• GATE output. The GATE also produces short pauses between notes to illustrate a re-trigger function.

Modulator (MOD)

The Modulator section is a Digital multimode Modulator that consists of:

1. A main OUT with a LVL control (+/-5V or 0-5V out depending on the mode)
2. A TYPE button, which lets you choose from the different types available. The Types available are (in their cycling order):
   • LFO (range is from 0.05Hz up to 1.000Hz)
   • Sample and Hold (range is from 0.1Hz up to 1.000Hz)
   • Envelope (from 1ms/stage up to 30 sec)
   • CC
3. The RATE slider, which corresponds differently to each TYPE and has also a second function via holding the SET button.

Envelope (ENV)

The Envelope section is a digital Triggered envelope that consists of:

• A Trigger input.
• A main OUT with a LVL control.
• A Slider, which controls the Fall Time. Holding the SET button while altering the FALL time controls the RISE time.

LFO

The LFO section is a wide range Analog Triangle Wave LFO that consists of:

• A CV input for the LFO Rate.
• A main OUT with a LVL control.
• A slider which controls the Rate of the LFO.

The range is from over 30 seconds up to 1000Hz

4-pole low pass filter (LPF)

The LPF section is a 24dB Low Pass filter that consists of:

• A CV for the Cutoff frequency. (expects +/-5v CV inputs)
• An audio Input that expects up to +/-5V levels
• An audio output (AC coupled)
• A potentiometer for the Resonance amount. At max amount self-oscillation occurs
• A slider for the Cutoff frequency. The range is from 20Hz up to 20.000Hz

Multimode Filter (12DB)

The Multimode Filter section is 12dB per mode and consists of:

• A CV for the Cutoff frequency. (expects +/-5v CV inputs)
• Three Inputs that get mixed and then pass through the filter input. Expects up to +/-5V levels
• One output for each mode (Low Pass, Band Pass, High Pass).
• A potentiometer for the Resonance amount.
• A slider for the Cutoff frequency. The range is from 20Hz up to 20.000Hz

Echo

The Echo section is based on the Erebus delay circuit and consists of:

• A CV input for the Delay Time. (expects +/-5v Cv inputs)
• An audio Input, which expects up to +/-5V levels
• An audio output.
• A potentiometer for the Delay Time. Normal mode is at about 300ms max delay. By removing a resistor, that is indicated on the top panel, you can get up to 1 sec delay time, but the sound of a delay, which is above 300ms, will be very dirty.
• A slider for the Feedback amount. Self-oscillation can be achieved from 90% and above
• A slider for the Dry / Wet MIX.

Specifications

• Length: 42HP (212mm) , Width: 3U (128,5mm) , Depth: 41mm (with the power board) , 33mm (without the power board) , Weight: 470 gr
• All 3.5mm jacks expect a mono TS type cable, except for the
• MIDI in, TRS type cable as suggested from the midi.org : https://www.midi.org/specifications/midi-transports-specifications
• All pots are 100KB (linear), and sliders 10KB (linear)
• Front panel is made of aluminum and is screen printed by hand.
• All bolts are M3, and if a replacement is needed a 6mm length type is suggested.

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