Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!usc!srhqla!nrcvax!mikey
From: mikey@NRC.COM (Mikey Goodglick)
Newsgroups: comp.sys.amiga
Subject: Re: Audio Filter on Amiga 1000
Message-ID: <406@nrcvax.NRC.COM>
Date: 9 Nov 89 20:10:20 GMT
References: <1574@ultb.UUCP>
Reply-To: mikey@nrcvax.UUCP (Mikey Goodglick)
Organization: Network Research Corp., Oxnard CA
Lines: 46

In article <1574@ultb.UUCP> klb3088@ultb.UUCP (K.L. Bell) writes:
>
>
>I would like information regarding the sound fix for the Amiga 1000
>to have a software switchable audio filter.  I remember somebody
>mentioning an issue of AmigaMail, but I do not remember which issue.
>Could someone point me to the source of said beast?
>
Here is a fix for ya...  This is a modification I did of a fix that was in
an Amazing Computing Issue.  My changes & additions will allow hardware
switching capabilities...Do the physical switch mode...it is REALLY worth
dilling a hole in your Amy case.  I have done 4 of these mods to date &
never had a disappointed "customer".  Of course if you don't wish to have the
added physical switch capability, just follow the instructions in the magazine,
for the software toggle only.


    			(Here's how....)

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.

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.

 

-- 
         **** 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