From - Mon Aug 26 21:19:04 1996 Path: masters0.news.internex.net!newshub.internex.net!newshub1.internex.net!news.Stanford.EDU!agate!howland.erols.net!news3.cac.psu.edu!news.cse.psu.edu!news.cc.swarthmore.edu!netnews.upenn.edu!dsinc!news.acsu.buffalo.edu!news.drenet.dnd.ca!crc-news.doc.ca!nott!bcarh189.bnr.ca!crchh327.rich.bnr.ca!woodcock From: woodcock@bnr.ca (Gregg Woodcock) Newsgroups: rec.games.video.arcade.collecting Subject: If you build harness converters, READ THIS!!! Date: 26 Aug 1996 04:23:54 GMT Organization: Bell-Northern Research; Richardson, Texas, USA Lines: 66 Message-ID: <4vr8sq$ahl@crchh327.rich.bnr.ca> NNTP-Posting-Host: carph33.rich.bnr.ca X-Newsreader: TIN [version 1.2 PL2] I set out to build a JAMMA sound amp module and put it off for a few days because I am a procrastinator. Boy am I glad I did becuase several things happened to allow me to construct a very excellent device. Breakthrough #1: Have you been saving those left over finger board pieces that you cut off to make them fit into a JAMMA female connector? Have you been wondering what you were going to do with them? Well I have an answer; they are PERFECT for the solder side when you only want to switch a few wires. That would be for things such as the Asteroids<->Asteroids_Deluxe, JAMMA sound amp, JAMMA video inverter, and JAMMA sync invert modules. You just sand them down a bit so that the solder can get a grip on the copper and bend the connector pins down a bit so they touch. You leave/cut a gap where you want to access the contacts and you have decreased ou wiring time by orders of magnitude!!! My job took 4 of the extra pieces and I had to cut one down a bit. Let me take this opportunity to recommend the purchase of a Dremel rotary tool. It makes cutting those finger boards a snap (I used to use a hacksaw with vice grips, UCK!). It easily allows you to cut the JAMMA key out of the finger board, too. Breakthrough #2: I was browsing the aisles at the local electronics junk store looking for small range radio broadcasters that I might use to do a broadcast "audio tour" of my home if we do decide to sell it (narrate onto a moebious looped tape and post a sign with the frequency) when I found the perfect thing for this project. Marlin P. Jones and Associates sells lots of very low cost kits to do these kinds of things and kit DK-27 "TDA7052 1W Power Amplifier" is just the thing. It is a 1W amplifier module with a 1" square PCB designed to be used as part of a larger project (i.e. *just* the amp stuff). The Philips TDA7052 is a general purpose 1W amplifier ideal for low power battery operations from 3V to 15V (I used 5V but in retrospect, I bet 12V would have been a better choice to reduce 5V current draw). Very few external components are needed (none in our case). No heat sink is needed. The design is short circuit protected and is intended for an 8 Ohm speaker (just like JAMMA)! This thing could not be more perfect!!! The amplification pot even comes with a plastic doohickey that sticks into it so you have a very usable knob. The PCB fits perfectly onto the edge of the 2 female connectors and wires into the assembly easily. The only drawback is that it assumes a Speaker - connectoed to Ground as the vast majority of amps do so you need to check your PCB before hooking it up. If you want to get one of these kits you can check your local place as the kits are very popular and common or you can order directly from MPJ&A (ask for a catalog while you're at it) at 407.848.8236. My price? Just $7.95+tax!!! Breakthrough #3: A few weeks ago, Jason Bardis (I am pretty sure it was him but I could be wrong) posted about the wonders of hot glue and I must agree. I use my hot glue gun more than I use my soldering iron and super glue put together. Those things are one of the most useful tools to have around and I don't know what I ever did without it. Anyways, when you get done bulding the converter, use the hot glue gun to glue the PCB to each female connector to lock it in place, then glue over the finger board pieces so that they are electrically insulated to help avoid shorts and other problems. I now have a very tiny, usable, elegant and virtually indistructible JAMMA sound amplifier module. I plan to build the other modules similarly soon! If you build an GameX->JAMMA converter and the sound is very low (such as the Nintendo games and Dig Dug among others), all you need to do is plug this additional module in to get the sound up! -- THANX...Gregg day 214.684.7380 night UNLIST/PUBL TEXAS NOT CANADA! woodcock@nortel.com or bn202@cleveland.freenet.edu *CLASSIC VIDEOGAME COLLECTOR BUY/SELL/TRADE NON-COMPUTER (ARCADE/HOME)* "If you quote me on this I'll have to deny it; I won't remember because I have such a bad memory. Not only that, but my memory is *terrible*."