All,

When I added a junked Firepower to my collection last winter I found my sound board needed some help and I've decided to offer what I created for it to you.

First, I had power supply problems on the sound board because of the 7805. They don't fail very often, but the do fail. With all the work I've done with switching regulators on WPC daughterboards, I decided to replace the original regulator with one of ezSBC's regulators. Unfortunately the "unique" mounting footprint on the sound board is not conducive to accepting the standard pinouts available and the pins on the regulator are actually header pins - not easily bendable to match the footprint. So I had a batch made up with a custom "triangular" leg configuration that fits into the sound board. When you swap out your 7805 for one of these ezSBC regulators you will not need to install the old heat sink - these regulators are way more efficient than the old linear regulators. The new regulator stands perpendicular to the sound board.

Once I got the sound board to reliably boot, I found the volume control potentiometer in my machine would only work in about 3 positions without dropping out or injecting a lot of static into the output. I also didn't like adjusting the voice/sound mix in the back box and the overall volume behind the coin door - I had to do a lot of "back and forth" to get it right. And I wanted more control at the lower end of the volume range. The obvious answer for this Daughterboard guy is a Volume Control Daughterboard. Simply unplug the long cable running from the back box to the lower cabinet and plug this daughterboard in it's place. As you can read about on my website, this daughterboard introduces non-linear control of the volume - meaning you will have more precise control at lower volumes but less precise control at louder volumes. In my home use situation this is perfect - during a party it needs to be loud, but when playing after the family beds down I want it low... but not so low that it is tough to hear. For me nonlinear works better so that's what I made. I am currently experimenting with linear versions but I'm not cannot promise when (or if) I will offer a linear version. My next target is the sound/speech mixer; I have a pretty good prototype of this one but it's not quite ready for prime time.

Anyway, I hope you like these - I think the prices are pretty fair $9 for the regulator and $13 for the Volume Control Daughterboard.

-Rob
-visit http://www.kahr.us to to get my daughterboard that helps fix WPC pinball resets

NEW: I now have for sale a linear version of the volume control daughterboard available. This board is for Williams System 3 through System 7 games.

As shown here, the linear volume controller tracks such that 1/2 turn results in about 1/2 volume where as the nonlinear controller offers greater control of low volumes at the expense of less control at louder volume. I'll continue to offer both options so you can choose what works best for you.

Nonlinear Control.jpg

-Rob
-visit http://www.kahr.us to get my daughterboard that helps fix WPC pinball resets

viperrwk,

Correct, only boards with remote volume control so not appropriate for type 1 boards.

Behind the back glass is convenient for my Firepower because that's where the speech mixer is - I tend to adjust both. Figuring that is a pain for sound-only games, I put labels on the blank pcb. That allows me to offer it without the 4-pin connector so it can be soldered in place of the original pot in the lower cabinet. I just haven't installed one that way in my machine to make sure it works as envisioned. Expect another update after I know it works.

And thanks for the compliment!

IMG_0758.JPG

-Rob
-Visit http://www.kahr.us to get my daughterboard that helps fix WPC pinball resets