Pin2k monitor upgrade revisited
Mickey Johnson
video amplifer on a Pinball 2000 monitor to increase the contrast by better
matching the computers output to the monitors input. It seems that its
possible to run into one minor snag that should be documented (it is very
easy to work around). What it amounts to is there are 2 different models of
the amplifer. The new version is powered by vga output, the old version
requires connecting to the 5 volt line of the power supply drive connector
of the pin2k computer. The problem is that not all vga card outputs have
that 5 volt line. My RFM did, and my SWEP1 did not. Now, if you have the
new style amplifier and don't have the 5 volts on the VGA output, you will
not get a picture (because the amplifier is not being powered). There is a
easy fix to this, you have to solder a wire to the amplifier pcb (its
documented at the amplifiers website) and run it to the 5 volt power supply
drive connector (which is what I did for my SWEP1). Note this entire issue
is documented at http://www.ultimarc.com/ .
Now as far as the results of adding the amplifier to the SWEP1. Wow, what a
difference. I thought the picture was good before, but now I see so many
small details in the picture that I never saw before. My machine now has a
very good black background (I have always been picky about black levels on
TV's) and the graphics just pop up bright and vibrant. Even the stars in
the background are bright as can be, lit against the deep black background.
I will admit that being in the arcade hobby for the last 8 years has made me
so picky about monitors that I can walk by just about and monitor or tv and
notice right away problems (too much of one color, bad contrast, poor black
level, minor raster issues, etc). I do think that if Pin2k would have
continued to be made, they would have moved to a videocard /monitor combo
that was better matched or they would have added an amplifier. Its such a
cheap way to make the two products perfectly matched as opposed to just
hacked together. Also for an exact description of what this amplifier does
here is a cut and paste of the description.
This is a standalone video amplifier which converts the 1 Volt output from a
VGA card into 4 Volts required by most arcade monitors.
The circuitry is exactly the same as that used on the J-PAC and uses a
high-bandwidth video amplifier chip. It provides an easy way of fixing a
"dim" arcade monitor installation by boosting the signal input to the same
level as a "real" game board.
The amplifer contains four channels, Red,Green,Blue and Sync. The Sync is a
buffer rather than an analog amplifier, and this is to avoid the "fold-over"
at the top of the picture on some monitors that are sensisive to DC input
levels.
Hope this helps, I will also email this to clay and he can decide if a
small note needs to be added to the Pin2k guide.
Later,
Mickey