Crash Sync

[rbcguitar]

I'm gonna try to breadboard/make a crash sync.

1st, does anyone have a non-handwritten schematic? lil' hard for a newb like me to read a handwritten one.

http://www.hollis.co.uk/john/crashsync.jpg

2nd, it looks like a 100k trim pot between 6 and 7 of 555, i dont have one, can i use a pot instead??

3rd, does anyone have a layout pic of this exact schematic?

[rbcguitar]

Sorry for quick bump, thought i'd change name of topic.

[JKowalski]

1: That schematic ranks way up there in legibility. I can read every part perfectly - I don't see how redrawing it would make it easier to use?

2: Yes you can. Trim pots and normal pots are exactly the same in every way except how you turn them and their size. Im thinking you might be assuming that it's a trim pot because it has two ends, and looks different from the other ones? That symbol for the pot between 7 and 6 just means it is set up as a variable resistor instead of a voltage divider (as in a "norm" pot with three lugs). To convert a three lug pot to a variable resistor, simply use one of the outside lugs (either one, though some pots are logarithmic so it will be different on each side) and the center lug for your two ends.

3: Search around a bit more, or try it yourself. Developing layouts seems daunting but you can do it. Just start out with an IC, and go from there, I use photoshop, but if im not mistaken at the top of this forum there is an excellent tool for doing this. Try that out. Or you can keep poking and see if someone's willing to make you one.

[rbcguitar]

"That symbol for the pot between 7 and 6 just means it is set up as a variable resistor instead of a voltage divider (as in a "norm" pot with three lugs). To convert a three lug pot to a variable resistor, simply use one of the outside lugs (either one, though some pots are logarithmic so it will be different on each side) and the center lug for your two ends."

Huh? can someone diagram what he means?

[Ripthorn]

What he means is you connect the center pin to one of the others (it doesn't matter which one).  You can do this with a jumper or if you make a layout, you can do it there.  That way the trimmer acts like a variable resistor as opposed to a voltage divider.  For more info, you can check out the GEOFEX article on pots.

[JKowalski]

http://sound.westhost.com/pots.htm

There is a good article that is nice and simple. Check out the sections titled "Trimpots" and the section titled "Putting Your Pot To Good Use". In the second, there is a diagram showing the different ways you can hook up potentiometers, the "variable resistor" method is the same as that symbol between pins 7 and 8.

It would be best if you read the whole thing, however!

[rbcguitar]

I need real help, im working on an techno project (major artist and label, btw) where i need my guitar to sound synthy, im already using an EH micro synth, whammy pedal, a byoc fuzz face (that i made) and some devi ever stuff, but the sound i hear in my head is the crash sync, i "need" to make this thing (this is my 3rd attempt to do so) I know it sounds crazy but i just dont get the handwritten schematic from JH not to mention missing a few parts (need to know what is essential component values and what is arbitrary).

Big question for today is: The opamp seems upside down from any pinout diagrams ive found, i wish he would of put this is 1, 2, 3 you know what i mean

Im really hoping someone will take me under their wing and help through this, I'll give you a special thanks on the album

Also, i want to make the ugly face next

PLEASE SOMEONE HELP!!!

[Ripthorn]

The opamp looks upside down only because in the schematic, that is standard schem notation for an opamp.  If you look at the data sheet of the TL072, the pin marked 1in+ is the + input to the first opamp, likewise with 1in- (-  input to first opamp), 2in+ and 2in-.   Vcc+ is just +9V and Vcc- is 4.5V.

As far as component values, what can't you make out?  It is very clear to me, but if you need help, let us know which values you are missing.

[JKowalski]

As rip said, tell us specifically which components you do not have.

Also, tell us what Op-Amps you have.

I can draw you a layout tonight, if I have the time.

What type of board are you using for this?




It's difficult just to BAM go straight into this like you are on a short notice. Even so, try to get something out of it rather then just following directions without thinking. It will help you later on, trust me.

[aron]

rbcguitar, you need to slow down. Some of these circuits are not easy to make - especially for a beginner. It's entirely possible that it's too hard for you to do this at the time. Take your time, do not omit parts - obtain the correct parts.

[ForcedFire]

Maybe you should just pay someone to make you one. Then when you have more time, you can sit down and build one for fun.

[rbcguitar]

Forcedfire;

No thanks, already coming together now.


jkolowski;

Thank you for making the schematic, now i get it, the handwritten one was confusing me 

I have everything, TL072 and 555, some of the resistors im having to run in series to get to the proper value. Eventually want to put it on a radio shack protoboard, right now its on my breadboard.

Its starting to happen, thank you so much. Message me with name, ill give you a special thanks.

aron;

Its not beyond me, ill get it. BTW, thanks for what you do, you are my inspiration bro.

[biggy boy]

I'm gonna try to breadboard/make a crash sync.


3rd, does anyone have a layout pic of this exact schematic?

This one?

http://www.hollis.co.uk/john/crashsynclyt.jpg

Glen

[Frances Rhodes]

hi everyone

is this the right schematic? i found this one doing some quick research http://doctortweek.files.wordpress.com/2010/09/crash-sync-redrawn-by-tweek.jpg
the second half of the op amp is inverted compared to the original drawing and this redraw that JKowalsky did. i guess the original drawing is the good one, but i'm asking just in case, just to be sure!

cheers