mikey.nrc.com (03/27/91)
This seems to be a popular issue on the net. Included is information on how to modify the Amazing Computing schematic to provide more flexability with the audio filter fix that Amazing released. What I have done is hook the main filter to a switch on the front of my Amiga to cut it out then a smaller switch on the side (near my power switch) to cut out the second stage anti-aliasing filter....(Yes, there is more than one audio filter in the Amiga, if my memory serves me correctly, there are 3!) This artical that Amazing put out allows you to toggle the sound output via software...that SAME software that the 2000 & 500 use... If you add my fix, you will have BETTER sound quality than the 2000 & 500...because you can cut out the main filter via HARDWARE AND SOFTWARE AND also have the advantage of cutting out the second stage via hardware. >Due to an overwhelmingly high response regarding my posting about the audio >fix for the Amiga 1000...I have decided to make this easy on everyone... >What I have done is taken the audio filter hack from Amazing Computing >issue Vol3 number 3. On page 64 the diagram of the IC I have changed a few >things. The 10k resistor no longer attaches to the base of the transistor, >it now goes to the center of a SPST switch (on/on switch). One of the other >ends of the switch goes to the 1k, the end that connects to the base of the >transistor. >Do not disconnect the 1k from the base. The other end of the switch goes to >pin 5. That is it...everything else hooks up as instructed. If I remember correctly, Amazing computing mentioned to just clip the second filter out by cliping the ends of two capacitors from the motherboard...I took that one step futher, by attaching the caps to a switch then attacting that switch to the side of my Amiga. This allows me to toggle the sound filter on and off when ever I pleases...DO THAT on a 500, 2000 or 3000!. >Remember: I cannot take responsibility for any problems that you may >encounter during this modification. >Let me know how you like your new HI-FI Amiga! >By-The-Way.. If you attempt the PAL fix on pages 58 & 59 of that same issue >of AC. DO NOT build it by the diagram, it is incorrect. The text is correct. The Amiga 1000 STILL LIVES!!! This hack works I know...I have had it in my Amiga for years now with no problems. I have also installed this hack in about 5 Amigas...all with no problems...everyone LOVES it. The best way I can describe the difference is image playing you Amiga through your stereo and having a sock stuffed in your speaker...the sound is really kinda bland (Amiga with filter on)... pull the sock out....the sound becomes suddenly VERY BRIGHT and FULL!! PLEASE contact me and let me know what you think of this hack!! ----------------------------------------------------------------------------- **** Mikey ****, "Changed my hair-style so many times In 3D, Part II, The Final Chapter now, don't know what I look like." A New Beginning...But this time, -Talking Heads Someone is waiting. ---------------------------------- (Amiga, a REAL Chameleon) | mikey@nrc.com mikey@nrcvax.UUCP