Doepfer A-197-3 RGB LED Controller
Module A-197-3 is a control unit for RGB LED stripes. The LED stripe is glued e.g. to the inner edges of the cases A-100P6/P9/PMS6/PMS9/PMS12 to illuminate the modules and patching statically or dynamically. Especially during live events the dynamic illumination in sync with the sound is an eye-catcher. Each color (red, green, blue) has available a manual control for the background brightness and a CV input with attenuator that enables the dynamic brightness controlled by other control voltages of the modular system. For example three envelopes can be used which also control the loudness or filtering of sound processing modules. But even other control applications are possible, e.g. LFO, random voltages, clock/gate/trigger signals, sequencer, Midi-to-CV.
These are the most important features of the module:
- Control module for static or dynamic control of RGB LED stripes
- So far RGB LED stripes with 1m and 2m length have been tested. But with a sufficient external power supply even longer stripes should be no problem. It might be necessary to equip the three power transistors on the pc board with additional heat sinks to avoid overheating of the transistors.
- Manual controls for red, green and blue (small potentiometers without knobs)
- CV inputs with attenuators for red, green and blue (small potentiometers without knobs)
The CV inputs are planned for CV signals (e.g. envelope generators, LFOs), not for audio signals with frequency selective processing like lighting consoles
The CV inputs are normalized, i.e. signal CVR is used also for CVG provided that no plug is inserted into the CVG socket, and signal CVG is used also for CVB provided that no plug is inserted into the CVB socket
- Control LED for each color
Notes: as the behavior of the control LEDs differ from the behavior of the LEDs used in the stripe the control LEDs should be treated only as a rough indicator, they do not exactly reflect the illumination of the LEDs in the stripe, to adjust the parameters in any case the LED stripe should be used and not the control LEDs of the module !
- The module has a trimming potentiometer available for each color for the adjustment of the basic brightness/offset of each color (to be able to adjust this parameter for different LED stripes). From the factory the trimming potentiometers are adjusted so that the LEDs of the stripe are just dark when the manual controls are fully CCW and no external CV signals are applied (or the CV attenuators are also fully CCW).
- Both the control electronics and the LEDs are very fast so that it's possible to realize even fast optical effects. To obtain e.g. a strobe effect all manual controls are fully CCW, all CV controls are fully CW and only CV input CVR is used. Then one obtains (nearly) white light pulses when short envelope signals or rectangle signals with small pulsewidth are used for CVR (e.g. the master clock signal).
- Required max. current with 1m RGB LED stripes: about 800 mA @ +12V (all three colors full brightness)
- The top left edge of the front panel features a gap for the lead-trough of the LED stripe cable. Therefore the module has to be mounted at the left edge of the case: top left if only the top edge of the case is used to glue the LED stripe, middle left or bottom left if the LED stripe is glued like a reverse "U" to three edges of the case
- The pc board is equipped with a pin header which can be used to connect the standard LED stripe that comes with the module
- In addition the pc board is equipped with a second pin header with 1/10" grid that can be used to connect the LED stripe that comes with the module or another suitable LED stripe supplied by the customer. The corresponding female connector with 30 cm long cables with open ends for free wiring is included.
- The module is suitable only for LED stripes with 12V power supply and common anode (+12V) with 4-wire cables (+12V/R/G/B).
- A suitable 1m long RGB LED stripe is added for free. Due to possible problems during installation (e.g. improper glueing/removing or folding of the stripe) it is not covered by warranty but should be treated as a free add-on.
- To install the LED stripe at least 10 mm width at the edge of the case have to be left and the substrate has to be suitable for the self-adhesive stripe (i.e. even and free of dust/grease). For example the A-100P6/P9/PMS6/PMS9/PMS12 are suitable. The aluminium rails of the case should be cleaned before the LED stripe is sticked on the rail. The low-cost cases (A-100LCx) are not suitable without modifications because the rim is too small and the self-adhesive stripes do not stick very good at the raw wood or the coating of the vintage versions. One would have to modify the low-cost cases e.g. by adding a metal or plastic band with at least 10 mm width from the hardware store to glue the LED stripes.
- As the LED stripes require a lot of current an external low-cost (wall-wart) power supply can be used for the LED stripes current to unburden the expensive high quality A-100 power supply (the LED stripes do not require a high quality supply like those built into the A-100 cases). To define the type of power supply (internal or external) for the LED stripe a jumper on the pc board is used. The external supply has to be ordered separately if required. A stabilized power supply with 12V DC output and 5.5/2.1 mm connector is required (polarity of the connector: plus = center). With other voltages the module does not work correctly ! If the module works as it should when powered by the internal A-100 power supply but not with the external supply the problem is apparently caused by the external supply (not +12V, not stabilized, high ripple, insufficient current or similar). A power supply with 1A is recommended for the 1m LED stripe.
- Alternatively the external power supply can be connected via a pin header on the pc board of the module. In this case the external supply has to be installed inside the housing by the customer. Sufficient electronic knowledge is required to install the additional power supply inside the housing ! In case of doubt please use the external power supply outside the housing connected to the socket at the front panel.
- Important note: Even when the LED stripes are powered from an external 12V supply the module has to be connected to the A-100 bus because the control electronics requires +12V/-12V. The external supply provides only the current for the LED stripes.