Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!pasteur!cory.Berkeley.EDU!johnhlee
From: johnhlee@cory.Berkeley.EDU (John Lee)
Newsgroups: comp.sys.amiga
Subject: Re: amiga PD digitisers ...
Summary: For hobbyists and brazen adventurers only.
Keywords: sound, digitizers, public domain, Cheezits
Message-ID: <11501@pasteur.Berkeley.EDU>
Date: 28 Mar 89 01:38:25 GMT
References: <3198@nunki.usc.edu>
Sender: news@pasteur.Berkeley.EDU
Reply-To: johnhlee@cory.Berkeley.EDU.UUCP (John Lee)
Organization: University of California, Berkeley
Lines: 63

In article <3198@nunki.usc.edu> wdao@sal49.usc.edu (Walter Dao) writes:
<Hello, I have up to now, gotten from this net, 2 diagrams for 2 different 
<sound digitizers. 
<The first originated from GEnie and was graciously sent to me. (it is a really
<simple circuit with very little number of components and wiring).
<The second was s direct post from <forgot his name> but was called (SD0809) .
<It was involving some greater amiount of components and would have involved a 
<lonnger building time. 
<
<now my question. 
<What are the differences ? Better sound quality at a lower requording rate ?
<(and therefore saving some precious MEM ?) 
<I am asking those questions to the actual users of these beasts. How do they 
<compare with actual commercial samplers (future sound, perfect sound, AMAS
< etc?) .

I created and posted 'SD0809' because I got some inquiries about a sound
digitizer using the ADC0809 chip specifically that I had mentioned in
another article.  I warned that I put in a 'kludge' in order to use the
chip, but people still wanted it anyways.

<I mean, do they produce a sample with background noice like WHUP-WHUP-WHUP_ ?
<or are those samples as pure as the original sound ? 
<
<yes , I plan on building one but I dont want to be disappointed and find out 
<that the sample made with the machine sounds like a dying cow when it should 
<have sounded like somebody saying "hello" .... And also a sample that has to
<much "scratch" sound in the Bckgrnd is not acceptable ...) 

I have my circuit built and running right now.  I have digitized several
samples, and I'm quite satisfied (surprised?) with its quality.  There is
no extra background noise except when the unit/input lines are unshielded,
which is to be expected.  As pure as the original sound?  Not if you're not
sampling fast enough.

Read the README I enclosed with the schematics.  I haven't seen the
other design, but I don't recommend you build mine because:
	1)  It can't digitize in stereo, ala Perfect Sound.
	2)  I pushed the chip 2x past its rated clock spec.
	3)  I built it because I had the chip laying around I wanted to
	    see if I could make a digitizer out of it, not because I
	    wanted to build a good sound digitizer.

<something that sounds like what is being produced in those commercial games 
<would be best. 
<
<             yeah,    that's it .....   that's the ticket. 
<
<
<  
<                      DW . 

Again, to recap, I posted the design for those who were interested in
experimenting with the ADC0809 as a sound digitizer.  If you want a
good stereo sound digitizer, don't use my design.  (It's fine for
a monophonic digitizer, though.)  Personally, I am going to build a
stereo digitizer using different chips (ADC0804, to be exact), but I
wanted to see if I could do it with the ADC0809.

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