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richardc64
Joined: Jun 01, 2006 Posts: 679 Location: NYC
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Cynosure
Site Admin
Joined: Dec 11, 2010 Posts: 966 Location: Toronto, Ontario - Canada
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analog_backlash
Joined: Sep 04, 2012 Posts: 393 Location: Aldershot, UK
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Posted: Wed May 15, 2013 4:12 pm Post subject:
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richardc64 wrote: | I couldn't find the original posting, but below is a schema using 2x 4051 and a 4029. |
I did look at my schematic today and thought "Did I really need the 4066s?" - obviously not! I built this before I started posting here and I must have learned a few things since then...
Cynosure's/PHOBoS' 4514 solution looks simpler, but this is a gate sequencer, if I've read it correctly, so you would need to add transmission gates in order to produce CVs from this (I think). Please tell me if I'm wrong .
Gary |
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Cynosure
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Joined: Dec 11, 2010 Posts: 966 Location: Toronto, Ontario - Canada
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Posted: Wed May 15, 2013 5:27 pm Post subject:
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The one I built was a gate, but the 4514 outputs Vdd voltage on each step. You can attach a pot to ground on each step instead and use it for CV just like you do with a baby 10. _________________ JacobWatters.com |
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elmegil
Joined: Mar 20, 2012 Posts: 2177 Location: Chicago
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Posted: Wed May 15, 2013 6:27 pm Post subject:
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Thanks Richard, I had my use of the 4051 going backwards, thinking I needed to wire it like the Baby-10. That's excellent. |
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analog_backlash
Joined: Sep 04, 2012 Posts: 393 Location: Aldershot, UK
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Posted: Thu May 16, 2013 12:45 am Post subject:
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Cynosure wrote: | The one I built was a gate, but the 4514 outputs Vdd voltage on each step. You can attach a pot to ground on each step instead and use it for CV just like you do with a baby 10. |
Thanks for the clarification Cynosure. I've seen a lot of 8- (or 10-) step sequencers based on 4017s in the past, which do include a 4016/4066 switch in the CV output circuitry. I think that I had this as a default "rule" in my mind. As you say, the Baby 10 works without this, so there's no reason why your circuit shouldn't work this way.
Gary |
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bunker
Joined: Mar 19, 2009 Posts: 58 Location: Manchester, UK
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Posted: Thu May 16, 2013 2:38 am Post subject:
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If you really want to use the LM3914 why not use it as nature intended? If the 'fade' is the only real issue then why not hook up 8x LED's and 8xLDR's? That way I'm assuming you can tailor the threshold of the LDR circuit so it switches a transistor on/off when the LED is above/below the 'fade' stage? A bit of a faf I know but it's an alternative to more IC's and should be an easier circuit to understand. Do a search for LDR circuits and you should be able to see how you can control the on/off threshold. |
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beep
Joined: May 05, 2013 Posts: 105 Location: Germany
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Posted: Thu May 16, 2013 2:07 pm Post subject:
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I think, I'll use the LM3914 in dot mode, because it does exactly what I want
on one chip with low parts count. I still want to quantize a variable control voltage to a defined scale for organic arpeggios from sample&hold sequences and stuff.
But first I have to build something nice for my girlfriend. it's her birthday this month _________________ Is the future obsolete? |
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L´Andratté
Joined: Sep 23, 2012 Posts: 150 Location: Hamburg, Germany
Audio files: 5
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Posted: Tue May 21, 2013 1:12 am Post subject:
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Reminds me of the Doepfer A152 Addressed Switch, which I couldn´t do without... It uses some chips called DG408DJ which seems to be some kind of dedicated 8-stage multiplexer.
http://www.digchip.com/datasheets/parts/dg/parts_dg06.php
Quote from datasheet:"Break-before-make switching action protects against momentary crosstalk between adjacent channels."
They have 2 or 3 in there-
I built my girlfriend an optical metronome, real simple but she´s fond of it with the piano, no more ´tock-tock´ |
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Dave Kendall
Joined: May 26, 2007 Posts: 421 Location: England
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Posted: Thu Jun 06, 2013 5:24 am Post subject:
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There's also the 4067 16-channel mux/demux chip.
cheers,
Dave _________________ "Everything in moderation, including moderation" |
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