11/30/2013
I originally wrote this "informal review" of Herg's LED OCD and posted it on Pinside.com.
11/30/2013
Altan's LED OCD Informal Review
Revision 1.03
Over the past few years many pinball owners have decided to "go LED". This is
likely encouraged by the ever increasing number of LED sources, recent pins by
Jersey Jack Pinball and Stern using LEDs, owners wanting to bling out their
machines, reduced power needs and heat, and because many pinball owners want to
tweak their own machines to perfection.
But Bally/Williams WPC machines were designed to use incandescent lamps and may
not take kindly to LEDs. At a very high level, it's important to understand that
LEDs and incandescent lamps have very different characteristics. For example,
LEDs can almost instantly turn on and achieve full brightness while incandescent
lamps have a longer "ramp up" time. The WPC software was designed to control
lamps with incandescent characteristics, not those of LEDs.
This mismatch causes at least 3 problems: ghosting, strobing and the loss of
fading effects. Ghosting occurs when a lamp should be turned off but instead it
flickers on and off dimly. Strobing occurs when the lamp should be "on" for a
period of time but rather than being continuously on for this period, the lamp
very quickly cycles between on and off. Some may call this flicking when the
on/off is further apart. Finally, loss of fading effects occurs because the
pattern of electricity that makes an incandescent bulb ramp from off to full
brightness in a period of time will typically cause an LED to stay off for a bit
and then strobe.
Note that WPC games control the General Illumination differently than the lamps
in the Lamp Matrix. While the lamp matrix can experience at least the 3 problems
listed above, the G.I. is typically troubled only by strobing and loss of fading
effects. Ghosting isn't a problem.
The LED OCD product is designed to solve the problems that occur when a WPC is
controlling LEDs in the lamp matrix (it does not address problems with the G.I.).
In addition to the problems mentioned above, the LED OCD product offers unique
control over each lamp in the matrix. The LED OCD also has the very nice ability
to concurrently drive both incandescent and LED lamps.
LED OCD has 3 main parts:
1) The main LED OCD board
2) A jumper/breakout board (which is unique to the WPC version of LED OCD)
3) Various cables
I was initially surprised by what seemed to be a significant number of cables
provided in the package. However, after closer inspection, I realized there
are not a large number of cables but rather 2 large cables and a USB cable. The
two large cables are special cables for LED OCD that have a single large
connector on one end and two smaller connectors on the other.
The first picture below shows the main LED OCD board. It is slightly larger than a WPC instruction card. The second picture shows the jumper/breakout board.
Installation should be straightforward for anyone that has experience pulling
connectors from inside the backbox. The large number of steps included in the
detailed instructions may make the process appear harder than it actually is.
Installing LED OCD requires no permanent changes to your pinball machine.
The installation involves:
1) Mounting the LED OCD board in the backbox
2) Mounting the jumper/breakout board in the backbox
3) Disconnecting the lamp matrix cables from the WPC driver board
4) Connecting these same cables to the jumper/breakout board
5) Using one of the supplied cables, connect the WPC driver board's output to
the LED OCD board
6) Using the other supplier cable, connect the LED OCD board to the
jumper/breakout board
7) Using a Z-connector, have power go to the LED OCD board
Originally the WPC driver connected directly to the lamps. With the LED OCD
board installed, the connection is
WPC driver board -> LED OCD board -> jumper/breakout board -> lamps
As can be seen from the sequence above, the LED OCD board is installed between
the WPC driver board and the lamps. At this location the LED OCD board is able
to look at the signals being generated by the WPC driver (which were designed to
control incandescent lamps) and convert them into an appropriate signal to drive
LEDs (or incandescent).
Installation took me about 30 minutes. The majority of this time was taken by
mounting the boards in the backbox and simply being careful. I had a little
trouble mounting the LED OCB board itself using the supplied adhesive mounts.
Even after cleaning the backbox area with isopropyl alcohol, the top right mount
didn't want to stick well. Also, there was a sticker on my backbox where one of
the adhesive mounts ended up. I think these could have easily been resolved with
a little more prep work on my part. For anyone doing the install, I recommend:
1) Use the screw mounts rather than the adhesive mounts
2) Look carefully where you want to mount the LED OCD board and ensure there is
no metal or other object in the way
3) Keep in mind there is a USB connector on the LED OCD board and you want to
ensure the mounting position allows access! Be very mindful of this! I suggest
connecting the USB cable when determining where to place the board.
Now that I've done the install once, I expect another installation would take 15
minutes.
Before talking about LED OCD's behavior in the real world, let's set a baseline.
I was playing around with LEDs in my Twilight Zone (with home ROM 9.4h). I
replaced a few lamps in the lamp matrix with LEDs to see how they compared to
traditional lamps. I was very unimpressed with the LED experience. This was the
same poor experience that I have had with other WPC games that have LEDs in the
lamp matrix. To me, there was terrible strobing when playing the game. The
effect was most obvious when the ball rolled over an insert. Also, with LEDs
installed, the fade effects were destroyed. Wham! It's on. STROBE. STROBE.
STROBE. Wham! It's off. And so on.
Note that I didn't have any ghosting problems because ROM 9.4h includes the
Williams change avoids ghosting.
For this experiment with LEDs in my Twilight Zone, I installed just a few LEDs
in the following inserts:
1) GUM insert
2) BALL insert
3) "Lock 2" insert
4) Bottom pop bumper
The LEDs I used are Pinball Life's "Ablaze 3-LED #555 Wedge Base Lamp" with
"Warm White" color.
I took a video to show this terrible strobing. A slow motion camera is required
to capture these LED behaviors because the cycle times exceed the regular 24, 30
or 60 frames per second offered by normal cameras.
With the LED OCD board installed, the change in behavior is nothing less than
amazing. The strobing is gone. The LEDs fade correctly. In short, the LEDs look
fantastic. With LED OCD, you can take advantage of the various colors,
diffusions, and brightness offered by the LED vendors and have none of the
traditional LED ill effects. The slow motion video shows how great the LEDs look
with the LED OCD board installed.
The following side-by-side video shows the standard WPC behavior on the left and
the LED OCD behavior on the right.
The default behavior of the LED OCD is to drive all the lamps in the lamp matrix
as LEDs using what is referred to as the 85% profile. However, each lamp can be
individually configured to use 1 of 8 profiles. A profile allows for an 8-step
brightness transition and delay that effects how quickly the 8 steps occur. The
default 8 profiles are named:
1) Incandes (for traditional bulbs)
2) LED 25% (max brightness is 25%)
3) LED 35%
4) LED 45%
5) LED 55%
6) LED 70%
7) LED 85% (generally recommended brightness)
8) LED 100% (maximum brightness)
I learned that 100% isn't the default because it may cause ghosting. With this
setting, the LED is enabled for as long as the lamp matrix allows. However, at
the electronic level the various components (transistors, etc.) are analog and
require a certain amount of time to engage or disengage. Because the LED 100%
profile doesn't account for this, you may see ghosting in the lamp that is in
the same row but the next column. The LED 85% profile plays it safe to ensure
this never occurs.
To make these "OCD" level adjustments, you connect the LED OCD board to a
computer using the provided USB cable. The software requires a Windows machine
to run, so Mac users (like me), Linux users, or any non-Windows person will need
to borrow a Windows machine or attempt to use a virtualization solution. The
software isn't completely self-contained, requiring other packages to be
installed (example, ".net" and a USB to RS232 driver).
I grabbed an older laptop with Windows 7 and gave it a shot. It didn't go
smoothly and took about an hour to get working. First, the USB cable provided
with the LED OCD is quite long and didn't interact well with my laptop. I
switched to a much smaller one I had and started making some progress. Second, I
had trouble installing the USB driver. After a couple of attempts and a few
reboots, it started working. The LED OCD site has a good troubleshooting section
that was quite helpful.
The LED OCD software is simple but effective. It comes with a set of data files
that associate the lamp row/column number with the friendly name. If your game
isn't listed, it's easy to enter the friendly names yourself. Alternately, you
can use a generic data file where the friendly name is simply the same as the
row/column lamp number.
With the WPC version of LED OCD, the software supports a "Pass-through" feature.
With the press of a button, the LED OCD board effectively disables itself
(although the signals still pass though the LED OCD board). This feature is
useful to perform an A/B comparison of the original behavior against what your
current masterpiece in progress offers.
Another nice feature is the ability to send a new configuration to the LED OCD
board without storing it permanently. You can try out various combinations
knowing that you can always go back to the original just by turning the game off
and back on. When you have found something you like, you can permanently save it
to the LED OCD board. Of course you can always save configurations to your local
storage and retrieve them later.
I was pleased to find the LED OCD board saves configurations in an easy to
figure out XML format. In my (unusual case) where most lamps are incandescent, I
opened the XML file in an editor and did a search and replace to change all
profile 7 (LED 85%) entries to profile 1 (incandes). That was much faster than
manually selecting each lamp and then selecting profile 1. Instead, I only
needed to manually change 4 entries (lower pop bumper, GUM, BALL, and "Lock 2").
Note: the video above was taken before I made this switch, meaning all lamps are
being driven with the 85% profile.
I've played around 30 games of Twilight Zone with the LED OCD board installed.
The strobing is gone, the fading is back. When I went back to the non LED OCD
setting, I was amazed how terrible it looked. I can confidently assert that I
would never think about doing a partial or fully decked out WPC LED game without
the LED OCD board. It solves the inherent problems which occur when putting LEDs
into a game designed for incandescent lamps and, in the process, removes the
need to purchase any of the expensive anti-ghosting LEDs.
Hope this has been helpful.
More information about LED OCD, including purchase information, can be found at
http://ledocd.comuv.com. Also, Herg is the inventor of LED OCD and is an active
pinside member.
... Altan
http://www.aaarpinball.com
Revision 1.01: Clarified purpose of Jumper/Breakout board
Revision 1.02: Added side-by-side video (and removed individual videos)
Revision 1.03: Moved to this web page. Added a few pictures and did
slight reformatting.