DIY version of Bastl Instruments GrandPa module and it’s SPA expander
Assembly difficulty: medium
We have been asked by people to bring microGranny into the modular and we decided to rethink the whole granular sampler idea to fit it best into small size eurorack module. Grandpa is the result! It has 2 trigger inputs to trigger 2 different samples. CV input which is assignable to any sound parameter and signal OUTPUT. The CV input can be also used to trigger grain shift. Grandpa reads microSD card accessible from the front panel and runs the same sound core as microGranny 2. For each sample you can adjust: sample rate, crush, grain size, shift speed, attack, release (full release is hold), start and end position.
- granular sampler with microgranny 2.0 soundcore
- plays wav files from the microSD card, 22050 Hz, 16 bit, mono
- 12bit output
- adjustable sample rate (can go up to 44.1 kHz)
- trigger inputs for playing 2 different samples with different settings
- each trigger input has a button to do the trigger manually
- RGB led to indicate page (on each page the two knobs adjust different parameters)
- crush distortion
- adjustable grain size and grain shift (positive or negative)
- digital attack decay envelope
- start and end point
- no interpolation between grain jumps
- each sample has adjustable destination of CV input – it can go to any of the parameters
- grain sync – CV input can act as trigger input for triggering the grain shift
- can recognize 35 different samples on the microSD card (they need to be specific name)
- 35 presets (all settings of the 2 samples is one preset)
- CV input reacts in 0-10V range
- breakout for FTDi USB adaptor for hacking, opensource firmware (see github)
Spa is an expander for the granular sampler module grandPa. It adds CV inputs for nearly all parameters and a clock input to trigger the grain shift. It doesn’t work without the grandPa Eurorack module.
The voltage on the CV inputs is relatively added to the grandPa settings on both channels A and B. All CV inputs react only to positive voltages. The update rate of these CV inputs is 20 Hz.
Four CV inputs have attenuator knobs. These CV inputs are normalised to 5V so the knobs act as a signal source when nothing is connected to the CV input.
- independent CV inputs for most parameters of the grandPa module
- CV inputs with attenuators are normalised to 5V so the attenuators work as direct controls of the parameters for both channels A and B of the grandPa
- CV inputs react only to positive voltages from 0-12V
- Grain Size and Shift Speed CV inputs with attenuators
- switch to select whether the other two CV inputs with attenuators control Start / End or Attack / Release parameters
- Crush cv input
- Grain Sync input to trigger grain shift
- GrandPA width: 5 HP
- SPA width: 5 HP
- GrandPA – 35mm deep
- SPA – 50mm deep
- PTC fuse and diode protected 10 pin power connector
- GrandPA current: <50mA @ +12
- SPA current: 25 mA @ +12V
- SPA connects to grandPa with a ribbon cable on the back side
For the successful completion of these kits you will need the following tools:
- Soldering iron (15-20W will do)
- protective eyewear
- flush cutters
- n2. hex screwdriver or allen key
- phillips screwdriver.
- one afternoon of free time
DIY Kit is containing:
- All necessary components
- Amount of tin that should be “just enough and a bit more”
- screws to mount you module in your rack
- Printed product manual
- Supercool bastl sticker
- Tons of soldering fun!
The complete step-by-step GrandPA assembly guide can be found HERE.
The complete step-by-step SPA assembly guide can be found HERE.
And dont be afraid of messing it up! If you will end up with malfuctional unit you can always let your module to come to daddy for repair;)