Akai MX73.
M.I.D.S.
Musical Instrument Display System.
MODE3.
(Super Enhanced Black) PMVA Display !
Available in the following colours.
Amber.
Blue.
Red.
Vintage. (Yellow/Green)
White.
All colours have a black background !
Display ships ready to Plug N Play !
NO Soldering or Modifications are required to install !
I designed this custom display, specifically to
Plug N Play in every musical Instrument with a character display. There are NO specific instructions for individual instruments, in rgds to the display set up. There is only ( 1 ) set of instructions for everything.
It's universal in nature !
MODE3 means 3 modes of operation.
1. EXTERNAL
2. INTERNAL
3. HYBRID
1. EXTERNAL mode. (majority of instruments)
External mode is used if the instrument has an existing contrast control, either via software or a physical potentiometer. When EXTERNAL mode is selected, INTERNAL mode is completely disabled !
2. INTERNAL mode.
INTERNAL mode is used if the instrument has no control to adjust the contrast, either via software or a physical potentiometer. When INTERNAL mode is selected, EXTERNAL mode is completely disabled !
3. HYBRID mode.
HYBRID mode is used if the instrument has NO control to adjust the contrast, and the thumbwheels are NOT accessible. So, in effect, HYBRID mode is INTERNAL mode on cable's (remote operation)
There are multiple instruments where there's NO contrast control, and the display is hidden, either inside a front panel, under circuit boards or deep inside a keyboard, this is where HYBRID mode is essential to control INTERNAL mode "remotely"
These 3 modes of operation, basically cover every possible configuration required, in every instrument that exists, with a character display. Period ! Its not necessary to make it any more complex than it has to be. 3 is the magic number. Covers all bases.
Adjustable BIAS !
This is a unique feature not found on any other display. It's possible to optimise the contrast on different instruments by switching between the two fixed settings. There's enough offset between them to make it useful. For ref, if you've ever purchased one of my black PMVA, in the past. The fixed bias setting on the old display, is the equivalent to MINUS on the MODE3. The PLUS setting, is the new addition to make it more useful, to create the offset.
After choosing the right mode of operation, INTERNAL or EXTERNAL, next step is to optimise the bias. This is done simply by visually checking the contrast adjustment on the instrument. One of them will be better than the other, logic dictates.
but MINUS is always the default. If you don't want to fiddle around with the BIAS, you can just leave it switched to MINUS, thousands of successful sales of the old displays mean, it's perfectly fine.
Important !
Bias MINUS is optimised for INTERNAL mode !
The circuit has been carefully calculated so the contrast thumbwheel is optimal at "midway" travel. So, if the MODE3 is switched to INTERNAL mode. You must always set the bias to MINUS !
Note !
It's fine to change the bias settings, while the display is switched ON ! It's not necessary to switch it OFF ! As long as the display is ON, initialized and logic voltage present, it's fine to switch between INTERNAL/EXTERNAL and bias PLUS/MINUS.
Ultra Bright LEDs !
The LED backlight in these MODE3 displays is unique and unusual. The LEDs are ultra bright types, I've done this to make the backlight adjustment much more useful. Instead of having a normal LED backlight and dimmer, it's now possible to adjust either side of "normal" brightness. If required, the backlight can be cranked up brighter, to OLED level brightness, or kept at normal levels. It's been carefully calculated to have normal LED brightness, at "midway" travel on the thumbwheel. It's also very useful when using different wavelength colours on the backlight. The red in particular, benefits from the extra brightness. Given the LEDs are ultra bright types, to start with, cranking them up to max brightness doesn't affect lifespan, as they are simply factory spec at max brightness. In fact, dimming them, increases lifespan further than the already superior lifespan, in comparison to OLED. Basically, there are no downsides whatsoever, to configuring the backlight this way, it's all positives. When your installing the display, after it's set up either EXTERNAL/INTERNAL, and the correct bias is selected. This is the final step.........
Set up the backlight brightness to suit your studio !
Finally, there are a few rules to pay attention too, to make sure you always achieve correct operation. When using HYBRID mode, the thumbwheels MUST be turned fully anticlockwise and "left" in that position. Fully anticlockwise, basically means, they are in
( bypass ) The adjustment is then done with the small white trimmer potentiometers on the cables (501) is the backlight (502) is the contrast. Both are screen printed for identification.
Also, in all cases (501) always plugs into display top position. There are various different MODE3 displays, but the layout is always consistent. Top position is always backlight (501) bottom is always contrast (502) You must attach the right trimmer, in the right place, otherwise the circuits won't operate correctly.
Where possible, the display PCB is screen printed, showing the correct positions, but it's not always possible to screen print on the tiny versions of the MODE3 displays.
So, as a general rule.........
(501) always plugs in, top position !
(502) always plugs in, bottom position !
Below, are some useful instructions of how the MODE3 is installed / set up, in the folllowing different instruments. Read through, then apply that knowledge, to whatever instrument your working on.
Akai VX90.
Roland D-110.
EMU Proteus 2000.
Roland D-550.
Lexicon MRC.
Roland JD-800.
Waldorf MW XT.
to follow............