two little questions about Crash Sync

[mitia]

Hi!

Firstly thank you for this forum... very interresting

secondly I'm french so excuse my poor english

thirdly I'm a newbee so excuse my poor questions

I'm building the Crash Sync by John Hollis and I have a few questions
Here's the shematic... http://www.hollis.co.uk/john/crashsync.jpg

1. it seems that my board is inversed. When i'm look at my board from
the iron side I see the circuit as I see it when i'm looking at the part layout there ... http://www.hollis.co.uk/john/crashsynclyt.jpg
so can you tell me if, as I think, I have to mount the two UC's upside down ?

2. I'm trying to wiring this with the GGG's tutorial there... http://www.generalguitargadgets.com/diagrams/switch_lo_3pdt_tb_battery.gif
what should I use for the "OUTPUT" ?

and what the two isolated holes named "bat sw" and "bat gnd" you see on
the layout are made for ? http://www.hollis.co.uk/john/crashsynclyt.jpg

well if someone could answer me this would be great!!!

thank you for reading
Mathieu

[Mike Burgundy]

1) If you've made the board mirrored (it happens to all of us) you need to mount the IC's *on the copper side*. Looking at an IC(with the little dent pointing upwards) the upper left pin is 1.  This pin should connect to the square pad. This is the only way to get all pins connected correctly, unfortunately. It's doable, but makes for some difficult soldering.

2) The OUTPUT is the lead from the effect's output, in this case that would be "depth 2" to the switch (the text on the layout assumes there's no switching)

3) bat sw= battery switch, bat gnd = Battery ground.
You connect the battery + to circuit +, and battery - to the battery- terminal on the board. Then, from the "bat sw" you run a wire to the *stereo input jack's ring connector*
A stereo jack has 3 connectors, tip, ring and sleeve. Tip and sleeve you also find on mono jacks, ring is the little ring after the tip. If you wire battery ground to this (you don't have to go via the board), there is no connection made between circuit ground and the battery- : no current can flow, the circuit is completely off.
If you insert a mono jack, the large sleeveon the plug will connect to both sleeve and the ring: the ring is shorted to ground, and voila, the circuit turns on.
This is common practice to save batteries from draining when the effect is sitting in a cupboard. The GGG wiring shows this setup too.

hih

[RickL]

1. It sounds like you do have your board reversed. If you're looking at the solder side of the board it should look like a mirror image of the part layout guide. The part layout guide shows the traces as if you were looking through a transparent board. A lot of the PCB layouts published on the net are designed to be used with PNP (press 'n' peel) or similar transfer paper so they are printed in reverse. When they are ironed onto the copper board the image is reversed again, bringing it back to the correct orientation. If you didn't use one of these methods the traces are probably reversed.

If so you have a few options. a) insert the IC's from the other side of the board. b) carefully bend all the pins on the IC's so the chip can be inserted upside down. c) use the "dead-bug" technique detailed at R.G. Keen's site to connect the chips [glue the chips onto the board upside down and run little wires from each of the legs to the proper holes in the board]. d) re-do the board so it doesn't come out reversed.

2) Output is from the wiper of the 100k pot. Bat gnd (battery ground) is the black wire of the battery clip. Bat sw (battery switch) goes to the ring connection on the stereo input jack. This is a system that lets you connect the battery to the circuit by plugging a mono plug into the stereo input jack. With no plug inserted the battery ground isn't connected to the circuit, when a plug is inserted it connects the ring and sleeve of the jack together which connects the battery ground to the circuit. Note that you can do the same thing by connecting the black wire of the battery directly to the ring connection on the jack. It's just a little neater to do it the way it shows in the diagram.

[mitia]

   

waouhh!!!
2 explanations for the price of one  :wink:

let me a little time
it should be ok now
I'll let you know

Mike Burgundy thank you !

RickL  thank you !

[jmusser]

Mitia, let me know how this circuit sounds when you get it done. Somebody on the forum told me about this circuit the other day so i could listen to the sound sample. I didn't know it even existed. It is very cool and has a unique sound. Good luck!

[Mike Burgundy]

Go here:
http://www.moosapotamus.com/
He's got something that's not exactly the same (envelope follower added) but the samples w/o envelope are spot-on.

[mitia]

Done
this thing is crazy!
I'm really happy of it.
I broke 2-3 pins when bending them ... too bad

the text on the layout assumes there's no switching

I should buy glasses I think...

Thank you for the help guys.

I can hear some noise when the effect is bypassed.
maybe have I to try another switching method...