From time to time I want to integrate a 12V Eurorack module in my 15V banana setup. So I needed a 15V to 12V adaptor. Nothing spectacular. Just from the datasheet.
The documentation and the Gerber files for download can be found in my website.
Just the standard configuration from the datasheets.
This module is thought for sending and receiving audio signals. I use it to add some external effects to my modular. Albeit simple, it is very useful. For connecting pedals and external CV sources I recommend my Pedal/CV Send and Receive module.
The documentation and the Gerber files for download can be found in my website.
The outgoing signal is attenuated 1:4 with IC1B. P1 sets the output signal level. The incoming signal is amplified 1:7 with IC1D. P2 sets the input signal level.
This utility module converts a 12V gate to a 5V gate. It is needed when you have a module with 12V gate output and your receiving module only accepts 5V gate voltage.
The documentation and the Gerber files for download can be found in my website.
The 12V input is divided down with the input voltage divider to 5V and buffered.
As a wind player I need to keep my hands on the wind instrument. This module was first thought for connecting pedals to my modular for changing control voltages. But it is useful to include external signal changers like echo or delay or any other sound and CV source as well.
The documentation and the Gerber files for download can be found in my website.
I think you need no description here.
This module is needed for easy connecting a banana system to a 3.5 eurorack system. It is a passive module. No signal changes are made.
The documentation and the Gerber files for download can be found in my website.
I think you need no description here.
CV Mover faceplate
This utility module provides you with different functions. You can use it as attenuator and sign changer for any input signal. You can use it as CV Source. It gives you a DC offset between -2.5V ans + 2.5V with coarse and fine adjustment. This voltage range is easily adopted to your needs with simple resistor change. Most interesting application is using it as “CV Mover”. This means adding a DC offset to the input signal. Say you have a LFO signal between +/-5V and want to shift it in the positive range. Then you can divide the signal in half with the attenuator to 1/2 and add the +2.5 threshold and you get a 0..5V positive LFO signal. This comes in handy for steering filters VCA’s and other modules. The output signal is visualized with LED
Specs and features
• CV source -2.5..+2.5V with coarse and fine adjustment
• Attenuator
• Positive and inverted output signal
• Adjustable DC offset for the input signal
• Positive and negative CV output indicator with LED
• Runs on +/-15V and +/-12V
The documentation and the Gerber files for download can be found in my website.
CV Mover: schematic
IIC1B acts as a simple inverting voltage adder. The input signal and the offset voltages are added together. The direct output from IC1B is the negative of the input signal. IC1A converts the signal back to the original phase. IC1C is a simple buffer and in the feedback loop of IC1D are the indicator LED’s.
CV Mover populated PCB
Voltmeter faceplate
The circuitry of this module was developed by Ray Wilson of MFOS. It was part of his Multi-Function Module. I have changed some resistor values to use with low current LED.
The LED voltage level meter gives you a graphical idea of where the voltage level you like to use to modulate your filter or VCA is. This circuit lights the LED in real time giving you a rough idea of the voltage level you are looking for. This is very useful when you want to move a CV from bipolar to only positive values.
Specs and features
• Three voltage ranges (+/-1V, +/-5V, +/-10V).
• Realtime LED display
• Runs on +/-15V and +/-12V
• Power consumption below 15mA each rail
The documentation for download can be found in my website.
Voltmeter schematic
IC4A is used for input buffering. IC4B and IC4C and associated components build the range selection circuitry. The heart of the circuit is the group of comparators build with IC1x, IC2x, IC3A and IC3B. The left side is used to measure the positive voltage, the right side for the negative voltage. LED 11 is the “near ground” indicator. IC3C and IC3D build a window comparator. For a more detailed description please refer to the original source at Ray Wilson’s Site MFOS (Multi-Function Module).
Voltmeter populated PCB
Voltmeter side view
VC LFO front
A VC LFO with multiple synced output waveforms is a very useful and versatile module. You can’t have enough of them. They can add a lot to sounds making them more animated. This one provides triangle, ramp up, ramp down pulse. square and sine wave output (-5V to +5V). The frequency range is easily adjusted to your needs from some minute per cycle up to 700Hz. I started with the VC LFO design form Ray Wilson MFOS but changed the exponentiator and pulse adjust schematic completely. I have added a range switch and a linear FM input as well.
Specs and features
• Synced triangle, ramp up, ramp down, pulse, square and sine wave output
• Output -5V to +5V
• log and lin CV input
• Voltage controlled pulse width
• Range switch
• Coarse and fine frequency setting
• Runs on +/-15V and +/-12V
• Power consumption below 10mA each rail
The documentation for download can be found in my website.
VC LFO schematic
VC LFO waveforms screenshot
VC LFO waveforms screenshot
VC LFO populated PCB
Basic PSU with 78xx voltage regulator
In many cases it is useful to have a easy to build fixed voltage PSU at hand. For this case I have made a PCB which works with the 78xx series voltage regulators in TO220 housing. The implementation follows closely a straight forward design as in the data sheet. I have tested this design with a current load of 1A for some hours. No problems whatsoever.
Specs and features
• Input: Select transformer according to your needs
• Output: Voltage depends on the regulator used / 1A DC
The documentation for download can be found in my website.
Basic PSU with 78xx voltage regulator schematic
Nothing special here. Just refer to the data sheet of the 78xx. Calculate R1 to keep the current through the LED within the specs.
Basic PSU with 78xx voltage regulator
Dual Sample and Hold: front view
Storing analog signals is a often used function in analog synthesizers. This sample and hold implementation follows closely the original Elektor Formant version of Book 2 “Formant Erweiterungen” p84ff. It is build for my Next Generation Formant project. Because I use the LM13700 here as replacement for the CA3080 I have build a dual sample and hold version. The PCB size is reduced from 100x160mm for a single version to 50x70mm for the dual version.
Specs and features
• Dual sample and hold
• 10Vpp input and output
• Runs on +/-15V and +/-12V
• Power consumption below 25mA each rail
The documentation for download can be found in my website.
Dual Sample and Hold: schematic
This implementation follows closely the original Elektor Formant implementation. Refer to the original documentation if needed. You can find it on the net. My changes are the input buffers, using the LM13700 instead of the CA3080 and the adaption to my 10Vpp signal level.
Dual Sample and Hold: populated PCB
Dual Sample and Hold: back view