From barry.klein@solar.orgTue May 23 10:57:38 1995
Date: Tue, 23 May 1995 04:05:00 GMT
From: Barry Klein <barry.klein@solar.org>
To: analogue@hyperreal.com
Subject: EM Book Update

Well I thought I would have had this done by now......
Anyway, first of all, On-Chip has given me the ok to reproduce all their
data sheets and even their two issues of Synthesource, in the update.  
However, if I am to do this they want me to remove all references to their
phone numbers, address, etc.(!)  So, apparently they do not want a lot
of onesy-twosy calls.  So what the heck - I'm up for it!  I am in the
process now of removing all such references from my master copy.

I am waiting for an ok from Analog Devices to include their SSM data sheets
too.  Should get an answer any day (my copy center won't even copy the
stuff until I do anyway).

I have put together a list of suppliers, both new and surplus, for IC's
and various components.  I have found a secondary (vrs. Analog Devices)
source for matched transistors, with a wider range of parts, and they
will select parts to your requirements too (probably if volumes meet
requirements).  This company is Linear Systems.  I am including their
product listing too.

The two sources for Q81 tempco resistors are given with contact info.

I went through the book chapter by chapter giving suggestions and
alternatives where applicable.  There will be no new circuits in the
update booklet.  If I am ever to get this out the door this is the way
it has to be.  Maybe a new book with totally new circuits after I can
get some time to "play".  So if you have the original book and are
pretty confident in making your way through it you probably don't
need the update booklet.  (and those SSM/Curtis-OnChip data sheets
will be quite a few pages!)

There were not as many circuit corrections as I had thought - I'll
list them below.  If you know of any others please let me know.  I
made these corrections in the reprinted version.

ELectronic Music Circuits Corrections

1.  Pg. 46 - (Keyboard interface) tie "+" input of A2 to ground
2.  Pg. 65 - (sequencer)  1 meg pot on 555 should go to pin 3, not +15V
3.  Pg. 129 - (VCLPF) tie top of R3 (and bus) to ground
4.  Pg. 67 - (Noise source) noise transistor is wired wrong. Ground base
             and connect C1 to emitter and R1.  Collector left open.
5.  Pg. 203 - (timbre modulator) "-" input of op amp in "- - - -" box 
	      goes to ground.
6.  Pg. 55 - (AD envelope generator)  should be a 3.9K resistor between
             the 4001 and the two diodes

That's about it.  I'll surely let you all know when everything is ready.

Barry Klein
barry.klein@solar.org
klein_b@a1.wdc.com (work address)
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