Euro Bits
This is the Euro version of the 4U Bits Module
Bits is a 12bit bit crusher module with waveshaping.
Bit Depth is continuously variable from 12 bits to 1.
Sample Rate is continuously variable in 2 ranges, audio and sub-audio
The waveshape control morphs through 8 patterns
There's a manually controlled pre-filter and an output crossfade control between the direct DAC out and a lowpass filtered output
The inputs and outputs are DC coupled allowing processing of control voltages
Stereo AC coupled Line IN and OUT (mixed to mono)
Wave, Bits and Rate are Voltage Controlled with "attenuverting" inputs
The 4U version is shown with the Euro panel to the left - all functions are identical in the Euro version
Build Notes
IMPORTANT: Teensy has changed the syntax of the Pedvide ADC library and my Arduino code will no longer compile without modification. Here are compiled HEX files that you can use to program the module using only the Teensy Uploader with no need to use Arduino.
Use this code for modules built without modification
REV 1.2 hex: Rev 1.2 hex
Use this code if you've done the mod for a 3 position rate switch
REV 1.4 hex: Rev 1.4 hex
Thanks to Frogleg Synthesis for the Euro PCB layout
Current build is Hardware Version 1.0/ Software 1.2
**The Euro PCB requires a jumper wire to fix a ground issue with R40. See the note below or download the pdf.**
BOM: Bits Euro BOM
HTML BOM:HTML BOM
Schematic: Bits Euro Schematic
R40 ground fix: R40 fix
Teensy 3.2 code (see note above): Arduino code 1.2
Install this library to your Arduino program if you don't have it:Pedvide:ADC-MASTER
** PLEASE NOTE: This should be considered an intermediate build. Construction is straight forward, but no build guide is included. You should be able to construct the module from a PCB, Schematic, and BOM. You need to be able to program the Teensy 3.2 from the Arduino IDE **
Alternate software 1.3
V1.3 changes the way the Sample Rate control works. This was trasitional code used for testing.
The Sub-audio switch position becomes EXTERNAL TRIGGER. With EXTERNAL TRIGGER The RATE CV IN becomes CLOCK IN. Sub audio internal clocking will not be available while running this version of the code.
Teensy 3.2 code (see note above):Arduino code 1.3
Alternate software 1.4
V1.4 changes the way the Sample Rate control works.
The choices are AUDIO RATE, SUB AUDIO RATE and EXTERNAL TRIGGER (The RATE CV IN becomes CLOCK IN)
This requites a hardware modification: replacing the RATE switch, adding 1 resistor, and a jumper wire.
** the build document has been updated to change the 100K resistor to 33K**
Hardware modification guide: hardware mods
Teensy 3.2 code (see note above):Arduino code 1.4
*** Only run this software if you have made the hardware modifications. The internal pull up is removed from Pin 6 and it will float without the 33K resistor installed. This could cause long term damage to the Teensy pin. ***
Bit Depth control can be set to work one of 3 ways:
1: Continuously variable number of bits from 12 to 1
2: Stepped cotrol from 12 to 1 (12,11,10,9,8, etc)
3: Bipolar control: With the BITS pot at 12:00 12 bits.
CCW rotation or negative CV gives stepped response
CW rotation or positive CV gives continuous respones
The code defaults to type 1. Un-comenting a line in the code sets the Bit depth response type
PCB sets include a main PCB, a panel component PCB, and a PCB panel
The Dual Gang 100K pot used for the pre-filter is now available in the US at synthCube (and in the UK at Thonk).
PCB board fix
There's an error on the Euro Bits board that should be fixed.
The module will work without the fix but the LINE OUT will be the same volume as the SYNTH OUT. Normally the LINE OUT should be half the volume.
Resistor R40 should be connected to ground on one side but isn't. The fix involves attaching a small jumper wire to one end of the resistor an attaching the other end to ground.
The easiest way is to scratch of a small area of solder mask and solder a small wire or resistor leg between that spot and the outer side of R40. Make sure you use enough heat to reliably solder to the groung plane.
