Quoted from kcirrick:My Ultimarc Video Amplifier Experience
I purchased the amplifier off of eBay thinking I would get it quick. No. It took ten days. While waiting for the amplifier I ran five volts from the computer and fabricated the cable I would need. Considering all the speak about how difficult this would be with a Ducksan I was a little apprehensive, but it was a slam dunk install. I cut the trace on the amplifier to separate the syncs, connected 5 volts, connected the wires to the amplifier as I had researched, powered up and adjusted the picture using the brightness, contrast and the flyback to get it the best I could and I was impressed. The amplifier really does make a huge difference.
The connector I had made was very loose resulting in a poor intermittent connection. I intended to buy a decent one, but since everything worked I felt safe cannibalizing the OEM cable and using that connector. Things still worked, but I couldn’t leave well enough alone and that’s when things went horribly wrong. I remembered reading about removing and jumping R4 to get better blacks. Okay, I can do that – and I did... on the amplifier. {You can laugh at the idiot now.} Too late I realized my mistake. Not R4 on the video amplifier. R4 on the control PCB. Strangely, the amplifier still worked, but I had no blue. (I don’t know if this is due to the damage I did to the amplifier or just my loose connector, but messing with the connector didn’t help.) I had gone ahead and jumped R4 up by the pots (without cutting the resister figuring “the path of least resistance”) and got a very dim colorless screen. Being unable to adjust and improve it, I removed the jump. The more I worked trying to recover blue the worse things got. Now no picture at all. I don’t understand. Adjust brightness, contrast, flyback no help. Figuring I had fried the amplifier I reassembled the original cable and still had no picture. I’m knee deep in it now and am terrified I've fried something important. I’m thinking I’m going to have to buy a new cable except, as we all know, they're impossible to find. Fortunately, I did eventually get the original cable working again and the picture was back the way it was prior to the install attempt.
I still wanted the amplifier and being a glutton for punishment, I ordered a new one – from England this time. I didn’t get it in three days, but the six days it took for DHL to place it in my hands was better than the ten days it took for the first one to get to West Texas from Oklahoma.
While waiting, I lost the battle with the six ball trough upgrade.
When the new video amplifier arrived, I started from scratch by cutting the trace on the amplifier. I reassembled my fabricated cable. Powering up I got a screen that looked like the horizontal hold had gone wild. I verified the trace was fully cut and that everything was connected correctly, but got no change. I pressed down on my fabricated connector and the screen flickered. Time to again cannibalize the OEM connector. Drum roll please… It worked! I adjusted everything trying to get the best picture I could. It could still use some fine tuning, but I have to admit that it is significantly better.
I still can’t leave well enough alone so I jump R4 on the control PCB after first clipping a leg on one end of the resistor this time. Again I have that dim colorless screen. No adjustments I could make would change it. I’ve got to be doing something wrong and I've had enough. I solder the severed resister back together, make some adjustments and leave it at that. You’ve seen photos of the difference this modification makes and they never do it justice so I won’t bother, but the picture is definitely worlds better. Before, the images were transparent. Now they are solid and bright. I would like to get better blacks still, but I’ve had enough of this for now. It’s time for a break from working on the video. Leave well enough alone. Whew!
I made this upgrade much more difficult than it needed to be. Anyone with a Ducksan installing the video amplifier, here is all you need to do.
Cut that trace on the video amplifier.
Open up the computer, tap into 5 volts and solder it to the amplifier exactly as shown in the instructions. (I added a little connector to the power wire near the amplifier so I could easily disconnect it if I needed to rather than having to unsolder it.)
Take a look at the OEM CGA cable where it connects to the monitors main PCB. You will see the red, green and blue wires split and each connects to two pins on the connector. Make your new connector just like this except do not split the red, green and blue. Leave pins 2, 4 and 6 empty.
Wire your new connector as follows:
Red to pin 1
Green to pin 3
Blue to pin 5
White (H\V) to pin 7
Yellow (V) to pin 8
Ground to pins 9 and 10
Connect the wires to the amplifier terminals as follows:
Red to Red
Green to Green
Blue to Blue
Yellow to Sync
Both grounds to ground
White to the remaining terminal
Do this and I guarantee it will work. It worked for me until I tried to make things better.
Now you just start adjusting the picture using the brightness and contrast pots on the control PCB behind the back glass and the flyback’s focus and brightness on the main PCB. Make sure the wires of your new cable aren’t too close to other wires back there as it will cause distortion on the monitor unless you’ve used a shielded cable.
Clipping and jumping R4 on the control PCB didn’t work for me, but then my machine is a prototype and things aren’t always the same as production machines – as in the opto PCB when attempting the 6 ball trough upgrade. If you want to try it I suggest just clipping the middle of one leg of the resistor and then jump it. If it doesn’t work then you can just solder that leg back together as I did.
I’m already working on my next project. The topper. I purchased the $100 topper found on Etsy meant for Arcade1up Attack from Mars. It’s simple, just two pieces of plexiglass, but it looks really good. It’s only back lit with a single white LED strip which is not very exciting so I’m customizing the lighting. This I can do.
That was quite the misadventure!
FWIW, I'm using the original WG monitor (new capacitors) with a Nucore computer and the video amplifier and I feel fortunate that it's all working quite well - the display looks like new.