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fredw
Joined: Jul 08, 2007 Posts: 10 Location: Berkeley, CA
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Posted: Sun Jul 08, 2007 1:13 pm Post subject:
Errata in "The VCO Chip Cookbook"? Subject description: LM741 pinout |
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On page 27 of "The VCO Chip Cookbook" a 741 op amp is shown.
Pin 6 is -input, pin 5 is +input, and pin 7 is output. However, the
data sheet for the 741 (and other op-amps) shows pins 2&3 are
inputs, and pin 6 is the output. Pin 7 is V+ and pin 4 is V-. Is
this a misprint?
Thanks, Fred. |
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Thomas Henry
Joined: Mar 25, 2007 Posts: 298 Location: Southern Minnesota
Audio files: 2
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Posted: Sun Jul 08, 2007 1:25 pm Post subject:
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It sure is!
You're the first person to have noted an error; thanks.
The pin numbers shown there would appropriate if using the second half of a TL072, for example. To go with the 741, change the 6 to a 2 and the 5 to a 3.
Thomas Henry |
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State Machine
Janitor
Joined: Apr 17, 2006 Posts: 2809 Location: New York
Audio files: 24
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Posted: Sun Jul 08, 2007 5:03 pm Post subject:
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Thanks guys, this will be noted in an errata report when the book ships from this point on. So far` I have the 1) Alternate figure for the XR2206 triangle output 2) This error in the IC pinout.
Thanks for spotting that !
Bill |
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fredw
Joined: Jul 08, 2007 Posts: 10 Location: Berkeley, CA
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Posted: Sun Jul 08, 2007 5:14 pm Post subject:
Sine conversion Subject description: Have prototyped two sine shapers |
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I've breadboarded both sine shapers, #10 and #11 in chapter one
of The VCO Chip Cookbook (per correction). Both work! The first
has some audible distortion (I used a 100k trimpot instead of 50k
but I doubt that matters). The second (#11) sounds very good indeed;
I substituted a 100k trimpot for R5/R4 as I had nothing else. Later
this week I'll measure it at my day job on a couple of analyzers, but I'm
very pleased with the results so far.
F. |
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Thomas Henry
Joined: Mar 25, 2007 Posts: 298 Location: Southern Minnesota
Audio files: 2
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Posted: Mon Jul 09, 2007 12:34 am Post subject:
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Good job, Fred.
Be sure to let us know what your distortion analyzer reports.
I can tell you that among the people I've shared both of these circuits with, literally half swear by #10 and the other half by #11! I've used both many times over the years, and in the context of making music (which is fairly imprecise due to room acoustics, amplifier distortion, and even human ear anomalies) I've found it hard to tell the difference between the two. But I do believe the feed-forward version is probably going to end up the better of the two.
Anyway, if you get some figures, let us all know. I'm very curious.
Thomas Henry |
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Danno Gee Ray
Joined: Sep 25, 2005 Posts: 1351 Location: Telford, PA USA
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Posted: Mon Jul 09, 2007 5:09 pm Post subject:
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Bill,
In a previous post you said...
Quote: | Thanks guys, this will be noted in an errata report when the book ships from this point on. So far` I have the 1) Alternate figure for the XR2206 triangle output 2) This error in the IC pinout.
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Would you please elaborate on item number 1? I'm trying to maintain correctness of my copy as we go along.
Thanks,
Dan |
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Dan Lavin
Joined: Nov 09, 2006 Posts: 649 Location: Spring Lake, Mi, USA
Audio files: 21
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Danno Gee Ray
Joined: Sep 25, 2005 Posts: 1351 Location: Telford, PA USA
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Posted: Tue Jul 10, 2007 6:22 pm Post subject:
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Wow...must have fallen off the planet for a while. I missed that one completely. Thank you for the link!
I now feel caught up. |
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State Machine
Janitor
Joined: Apr 17, 2006 Posts: 2809 Location: New York
Audio files: 24
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Posted: Tue Jul 10, 2007 7:33 pm Post subject:
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Quote: | Wow...must have fallen off the planet for a while. I missed that one completely. Thank you for the link! |
Thanks Antman !!!!
Bill |
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