Easy EGRET II speaker upgrade


How to put a 2.1 speaker system into an EGRET II with or without intrusive measures. Very easy to do as long as you know how to do it and what you’ll need. Speaker choice After a whole-heartily recommendation (i.e. “these are cheap, mate”) I went with the Logitech s220 as they are at an extremely good value.

Logitech s220

The smaller speaker will fit in the originals place by a slight wedge-in manoeuvre
The bass is “just right” and is small, so it fits very well behind the coin box
The little wired remote has volume control and a speaker muting phones outlet
Very competitive price

Doesn’t have bass adjustment on the remote
Doesn’t fill the hole made for speakers in the cabinet completely, but that’s easily solved with some pieces of cardboard Parts needed (to keep JAMMA compatibility)

If you plan on keep running your JAMMA PCBs in your cabinet and not only stereo, line-output systems such as CPS2, NAOMI, a PC or gaming consoles, besides a set of 2.1 speakers you’re gonna need more stuff.

JAMMA boards output amplified mono, so running that straight into a small amplifier (your woofer) will give you:

a) distorted audio (best case)
b) a broken amp on your JAMMA board (worst case)
c) both

So, you’ll want to find (and then buy) a “speaker to line” or “high to low” audio converter. These comes in all shapes and forms and if you are good at building stuff, you can Google for it and come up with how to solder one up yourself. Here’s what I have:

High To Low convert

Important notice!
Monouchi alerted me on the fact that you HAVE to turn the volume all the way down on the EGRET II’s built-in volume control, or your high->low converter will eventually stop working. Running the PCB’s sound on low volume is recommended as well. You should notice distorted audio if you run your games volume too high as well.¬†

Hooking up the “high to low” converter can be done in three ways;

Locate (then buy a couple of) the JST connectors that matches the ones that are attached to your original speakers and attach those to the “input” side of your “high to low” converter. Too find the pinout you might want to open the original speakers carefully as I myself went the “lesser” way now referred to as #2 (as I never thought of this clever JST trick, thanks to monouchi for figuring that one out). And then your high->low work is done.

JST conversion

A bit down is also monouchi’s very clever mounting for the “high to low” converter.

Cut the wires from your JAMMA harness for access to your SPEAKER+ and SPEAKER- then connect these to the input of your “high to low” converter. The converter should be STEREO in/out but it can be set to accept MONO then output DUAL MONO by hooking it up like this:

JAMMA SPEAKER- is connected to R- AND L-
JAMMA SPEAKER+ is connected to R+ AND L+

Hooked on JAMMA!

To my knowledge this is harmless (the mono->dual mono thing), that’s not saying there’s not a better, “proper” way though.

Not a “permanent” solution, but easy to remove if you only want to try this and option 1 or 2 is not an option for you.

Then you put the converter in an easy to reach place inside your cabinet. I mounted one behind the wooden board where you can screw PCBs onto, and the other I just have on the floor of the cabinet (I have a PCB holder in that cabinet, so the floor is always free). Or take a cue from monouchi and mount it like this (notice the JST’s):

Mounted the monouchi way


Either three methods leaves you with unamplified RCA output (unless your “high to low” converter has some other connector, or just wires). Most 2.1 systems has a male mini-phono for hooking itself up to a computer, so you’ll need to supply a female mini-phono instead of the RCA output:

RCA-/>Mini Phono” width=”580″ height=”163″ /></h2>
<p>Mounting the new speakers in the EGRET II</p>
<p>The hardest part of this process is actually removing the original speakers. If it’s not those pesky screws from those angled frames into the original “cans”, it’s the JST connectors running from the short speaker wires into the longer wires descending down into the cabinets that won’t let go after years of smoke, dirt and whatnot.</p>
<p>1. Make sure that the wires to the new speakers are lengthy enough to reach from one side of the cabinet to the next. If not, pull the left and right speaker wires apart until the plastic “bridge” between the speaker wires slowly but surely gives way. If you don’t understand what I just wrote, look at the small adapter above, and think about pulling the red and black RCA ones apart. Like separating Siamese Twins.</p>
<p>2. Measure the width of the speaker holder in the cabinet and cut two rectangular pieces of cardboard (the needed length is about twice the width of the holder).</p>
<p>3. Unplug your cabinet from the wall socket.</p>
<p><strong>The actual mounting</strong></p>
<p>Once you’ve removed the original speakers, rest the new speakers on top of your bezel/bezel surround. Put the speaker marked L to the left etc. for correct stereo-sonic playback.</p>
<p>Guide the wire that’s going to the sub woofer gently down through the bezel and behind the rotation mechanism (out of the way for the rest of the operation). Make sure that the phono connector for the speakers doesn’t hit anything on the monitor chassis on the way down. It’s metal after all.</p>
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Now look at my picture below (right speaker pictured):

rusty 1

You put the speaker in place from the front (look at the cable coming from the speaker) and wiggle it gently into the hole in the bezel surround. You’ll feel that the friction will “grip” the speaker. The first time, I thought about securing it a bit more with masking tape, but it fits real snug without it. Once the speaker is in place, you put the cardboard between the marquee light and the speaker. The speaker will hold it in place and you won’t get irritating light leak from the speaker containers.

Installing the sub woofer

You can put it behind the coin box, like I did, or somewhere else in the back of the cabinet. I chose this spot because I just don’t like to imagine the magnetism breaking any of my PCBs (if this is possible).

In the picture below, you’ll see the bass knob, and right below is where the top speakers are connected. Under the speaker output, you have the line input wire. I’ve set my bass level to maximum, and it feels perfect. I’m not even bass crazy.

Extra power outlets, stepdown and sub woofer

No, I haven’t had time to make the wiring all neat (below), but everything works just fine. You don’t see any wire coming OUT from the “high to low” converter, because I have a CPS2 mobo hooked up right now, straight to the sub woofer.

More power outlet info

Here you can see external, non-JAMMA audio hooked up on the floor right outside the cabinet. I took the CPS2 game out so I could take better pictures of the inside of the cabinet.

taped holes

Not so hard, is it?

1 comment

  1. Hello there emphatic, I am also interested in this. (Please take a look at my most recent article for details.) This was a great read; you have most definitely provided me with some food for thought.

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