My vanishing point has some ISSUES

[lightningfingers]

the clock will not, well, clock. The output stays constantly high. I have checked with a meter, all positions of the 100K pot it stays the same (I'm usinng a 4049 BTW).

Schematic Here: http://www.geocities.com/thetonegod/vanpoint2/van_point2.html

Anyone have any suggestions? I know the clock is simple enough....I have tried a different 4049 (in fact, tried 3 different 4049's)

[Arno van der Heijden]

I don't know whether this can be checked with a meter.
Instead, you can also try to hook it up to an LED (in series with a resistor) and check whether the LED will pulse.

[lightningfingers]

I tried that just now but it the led stays on, just as if i hooked it to the +VE rail.......

[The Tone God]

The circuit uses 4093s not 4049s. The 4093 is a schmitt trigger NAND gate. The 4049 is an inverter gate without the schmitt trigger inpuit so that particular clock circuit will not work.

There are other common clock circuits that the 4049 can use to drive the 4017 with.

Andrew

[lightningfingers]

I see. Now i'm completely f    cked. Oh well. One more quick Q, with the 4093, do I still need to ground the in/outputs of the unused gates?

[The Tone God]

I see. Now i'm completely f    cked. Oh well.

If your using the PCB that I offer then yeah your screwed. If you are doing your own board or breadboarding it then just use the common two gate clock circuit you see everywhere with the 4049. You'll have to retweak everything to work to your tastes.

I also have an untested layout for the 40106. It includes an LED output for the sequencer clock so you can see the speed of the even in bypass.

Did you do a look up for a post I made awhile ago concerning a collection of changes to improve the performance of the VP ? I haven't updated the article with the changes yet.

Check out my post in this thread:

http://www.diystompboxes.com/sboxforum/viewtopic.php?t=28396

One more quick Q, with the 4093, do I still need to ground the in/outputs of the unused gates?

Yes. As with all unused logic gates in ANY circuit tie the inputs to either ground or V+but only the input. Leave the output unconnected.

Andrew

[Arno van der Heijden]

Andrew,

I (STILL) have my VP2 on the breadboard (the logic part that is), tweaking it for perfection.
I'm trying to replace the optocoupler that changes the frequency of the RF clock with a transistor (à la zvex   ), because the use of diy optocouplers on the breadboard really annoys me. I'm using this (http://www.geofex.com/Article_Folders/LFOs/psuedorandom.htm) as a guideline.

Right now, I have the transistor in the feedback loop of the second clock. The base is connected to the clock via a 100k resistor, and to ground via a 1M resistor. I'm getting reasonable results this way, but still not perfect.
Have you tried something like this? Do you have some tips?

[The Tone God]

I (STILL) have my VP2 on the breadboard (the logic part that is), tweaking it for perfection.
I'm trying to replace the optocoupler that changes the frequency of the RF clock with a transistor (à la zvex   ), because the use of diy optocouplers on the breadboard really annoys me. I'm using this (http://www.geofex.com/Article_Folders/LFOs/psuedorandom.htm) as a guideline.

Right now, I have the transistor in the feedback loop of the second clock. The base is connected to the clock via a 100k resistor, and to ground via a 1M resistor. I'm getting reasonable results this way, but still not perfect.
Have you tried something like this? Do you have some tips?

I just made a post in the "home-made vactrols" thread about my thoughts on why I used optocouplers. I haven't tried using a transistor for the HF clock...YET! It maybe something to play with alittle later. I have so many things on the go right now. I'll see if I can squeeze something in when I'm suppost to blink. :shock:

Atleast using the optocouplers reduce the flaming I get on german forums.

I would still use a optocoupler for the audio/logic interface.

Andrew

[Arno van der Heijden]

I just made a post in the "home-made vactrols" thread about my thoughts on why I used optocouplers. I haven't tried using a transistor for the HF clock...YET! It maybe something to play with alittle later. I have so many things on the go right now. I'll see if I can squeeze something in when I'm suppost to blink.  

Yeah, I just read the other thread. A fet doesn't seem to be a good solution here, but a transistor, if I can get it to work, does, as it only needs a couple of extra components.

I would still use a optocoupler for the audio/logic interface.

Yeah, that was my opinion as well.

[The Tone God]

Yeah, I just read the other thread. A fet doesn't seem to be a good solution here, but a transistor, if I can get it to work, does, as it only needs a couple of extra components..

Cool. I'll play with it maybe later today in between projects. Just off the top of my head it might be possibe to put a transistor in between the timing cap and ground. That might be better then putting the transistor in the loop. Just a thought.

Andrew

[Arno van der Heijden]

Just off the top of my head it might be possibe to put a transistor in between the timing cap and ground. That might be better then putting the transistor in the loop. Just a thought.

I really don't know. I have a good basic understanding of how the building blocks of electric circuits work, but I don't have much knowledge regarding the specific workings of transistors or these kind of oscillators.
I seem to remember, however, that zvex put the transistor across the resistor. Right now I don't even have a resistor, only a transistor. I think I'm gonna experiment with a resistor and a transistor in parallel first.

[lightningfingers]

Thnaks Andrew Now if I can just get through the rest of today without being stupid I might have a build report by tomorrow :wink:

[The Tone God]

Thnaks Andrew Now if I can just get through the rest of today without being stupid I might have a build report by tomorrow :wink:

lol. No prob. I would love to hear/see another build report.

I seem to remember, however, that zvex put the transistor across the resistor. Right now I don't even have a resistor, only a transistor. I think I'm gonna experiment with a resistor and a transistor in parallel first.

I don't remember anything like that or know how Mr. Vex does it as I have never looked in one of his boxes and quite frankly I don't care. I have no interest in reverse enginering someone elses stuff. I prefer to find my own way. If it ends up like someone elses product then it shows they have style. My interest is more in making something simple, reliable, cheap, and when making it availible to the public easily reproducable. /rant

I'll post my findings when I play with this.

Andrew

[Arno van der Heijden]

I don't remember anything like that or know how Mr. Vex does it as I have never looked in one of his boxes and quite frankly I don't care. I

I have never looked in one of his boxes either, but I seem to remember a comment he made about it on this board.

My interest is more in making something simple, reliable, cheap, and when making it availible to the public easily reproducable. /rant

Exactly. This is not meant as critisism on your cool design, but these are all arguments not in favour of a homemade optocoupler.

[The Tone God]

Exactly. This is not meant as critisism on your cool design, but these are all arguments not in favour of a homemade optocoupler.

Agreed which is why I'm willing to play with this some more. That is the fun part about DIY, if you don't like something you can change it.

Andrew