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alanwilder81
Joined: Sep 03, 2016 Posts: 310 Location: italy
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alanwilder81
Joined: Sep 03, 2016 Posts: 310 Location: italy
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Posted: Mon Oct 03, 2016 10:01 am Post subject:
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please excuse me for the bad picture resolution but apparently i couldn't get it any better |
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Cfish
Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Mon Oct 03, 2016 10:29 am Post subject:
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Hi alanwilder81
I can't see the pic well enough to see -10v anywhere in the red circle. I am using an iPad' so that does not help. |
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Cfish
Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Mon Oct 03, 2016 10:32 am Post subject:
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By the way, I am using the 4066 for a sample and hold circuit for my current version I am working on. I got the idea from a Ray Willson schematic. |
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Cfish
Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Mon Oct 03, 2016 10:38 am Post subject:
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Alanwilder81
If you are building this on perf board, don't forget the +v to pin 14 on the 4066 and the 0v ground on pin 7.
I spent an hour yesterday over that exact problem |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Mon Oct 03, 2016 10:46 am Post subject:
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Your could use a 79L10 voltage regulator supplied from the -12V (with the capacitors and possibly diodes around as suggested in the data sheet for it).
Or even connect it to the -12V rail, but the 10V really is to isolate stuff a bit from the supply voltage in order to make the circuit more stable (less drift, less false triggers). _________________ Jan
also .. could someone please turn down the thermostat a bit.
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Cfish
Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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alanwilder81
Joined: Sep 03, 2016 Posts: 310 Location: italy
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Mon Oct 03, 2016 12:38 pm Post subject:
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alanwilder81 wrote: | Is it not gonna make too much heat ? |
Only when by accident you did something wrong .. there is almost no current flowing trough it, so it should not get warm at all. _________________ Jan
also .. could someone please turn down the thermostat a bit.
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Cfish
Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Mon Oct 03, 2016 12:43 pm Post subject:
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Alanwilder81
My only problem, only arose because I chose to use a comparator to get a gate signal.
I didn't think about sample and hold at that moment.
The problem I have, is in my own planing and design. An uneducated mans mistake. However I am learning just like anyone who isn't dead.
I just try really hard to point out things fast because I don't want someone to get discouraged on my account.
The first schematic on this page works great for what I needed it for at the time. I'm still trying to make it something better, and better.
I really like this thread because almost everyone here has at one point in life wanted something better than the cigar box organ schematics. But not quite been to building a MIDI to CV converter.
By the way. I have built a wonderful aurdino based MIDI to CV converter. Loosely using a Ray Willson design. I really don't need more full analog key beds. This type of circuit just intrigues me. There is a lot going on in it. |
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alanwilder81
Joined: Sep 03, 2016 Posts: 310 Location: italy
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Posted: Mon Oct 03, 2016 12:57 pm Post subject:
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hi Cfish,
i am surprised you chose to go digital, because not longer than a couple of weeks ago you claimed you wanted to get a full analog controller
But hey, if it works for you then it's alright! i am still trying to wrap my head around the basics and the old school stuff. So, despite digital being relatively easier, i like the idea of staying analog and really learn comparators, op amps,the classic analog signal manipulation and synthesis.
total green horn here, so bear with me. It's an immensely fascinating world i m desperately trying to get grasp with |
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alanwilder81
Joined: Sep 03, 2016 Posts: 310 Location: italy
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Posted: Mon Oct 03, 2016 1:00 pm Post subject:
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thanks BlueHell |
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Cfish
Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Mon Oct 03, 2016 1:05 pm Post subject:
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Alanwilder81
I built the MIDI controller. However I had to have my brouther Matt program the micro. I hate that I don't understand part of what I built. That's why I'm here doing this.
I could have built Ray Willsons keyboard design. I just couldn't figure it out. Was too much for me to understand how it worked. I like understanding it. So I break it down till I do. |
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alanwilder81
Joined: Sep 03, 2016 Posts: 310 Location: italy
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Posted: Mon Oct 03, 2016 1:16 pm Post subject:
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to Cfish,
i also hate the idea of not understanding what goes on in a given circuit.
Sadly i am a novice in electronics,i dont have a EE degree so i must rely on good schematics without being able to get what each component or section does what.
Frustrating, i know,especially when it comes to troubleshooting.
But it's rewarding to listen to the VCO s and VCF s juice the speakers output nevertheless. One day,i might be able to fully grasp electrons flow |
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Cfish
Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Mon Oct 03, 2016 1:23 pm Post subject:
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4066 is just a fast switch. The capicitor after it holds the sample voltage for the opamp.
This lets you pick up the key and the note stay the same.
If this does not happen, when you pick up the key and the envelope generator keeps the gate open on decay, the note would change |
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alanwilder81
Joined: Sep 03, 2016 Posts: 310 Location: italy
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Posted: Mon Oct 03, 2016 1:33 pm Post subject:
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hey cfish,
i've recently built your CV GATE circuit, and what you described ,is exactly what happened to me. Due to the lack of the sample and hold.
As soon as i released the note, the circuit would stop sending voltage to my VCO, and consequently the note would changhe in pitch
With ADSR zero release time setting, that wasn't noticeable,but of course it was on medium or long release settings.
So, the sample and hold just keeps the output voltage even, until next event.Simple yet astonishingly useful |
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Cfish
Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Mon Oct 03, 2016 1:41 pm Post subject:
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Alanwilder81
The pic I posted above is the sample and hold I am installing.
Look at your schematic you are now using and compare everything after the 4066.
After the 4066 is sample and hold. Mine has glide. Didn't look to see if yours does.
But glide just charges a capicitor to slow the change between keys. |
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Cfish
Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Grumble
Joined: Nov 23, 2015 Posts: 1294 Location: Netherlands
Audio files: 30
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Cfish
Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Thu Oct 06, 2016 12:45 pm Post subject:
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Thanks grumble
I am using TL071 there. I built a quick rig to test the sample and hold and it works good. Took me borrowing my brouther much better scope to be sure, but it is just sampling 0v as the cv drops before the comparator swings negative.
Thanks for the recommendation, I would never thought of that. Was just luck I was using TL071 |
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Cfish
Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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alanwilder81
Joined: Sep 03, 2016 Posts: 310 Location: italy
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Posted: Tue Oct 25, 2016 8:07 am Post subject:
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nice job Cfish ! |
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alanwilder81
Joined: Sep 03, 2016 Posts: 310 Location: italy
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Grumble
Joined: Nov 23, 2015 Posts: 1294 Location: Netherlands
Audio files: 30
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Posted: Tue Oct 25, 2016 3:30 pm Post subject:
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The difference between the 4066 and 4016 is mainly the resistance in ON position, which for the 4016 is typical 400 ohms @ 15volt and for the 4066 this is 125 ohms @ 15volt. This impedance R-on is for both types Power supply voltage dependant (lower VCC means higher R-on).
Since there is a resistor of 4k7 in series with the switch, it is ok to use a 4016 in this application, but maybe change this 4k7 resistor with a trimpot to compensate for the higher R-on of the 4016 if the slope of the CV is not steep enough.
Something to read about switching: http://www.thetonegod.com/tech/switches/switches.html |
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Cfish
Joined: Feb 24, 2016 Posts: 477 Location: Indiana
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Posted: Thu Oct 27, 2016 3:46 am Post subject:
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Hi guys
Was going to board up the schematic alanwilder81 poasted. Am curious about all the reasons for using the LM339 for the comparator in the schematic.
Have ordered a few. But it's not one I keep on hand.
Have been looking at datta sheet. However there is a lot in a datta sheet that I don't fully grasp yet.
Would really appriciate your input. |
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