Crackle Box DIY Synth Project

daukterjones · Joined: Mar 28, 2006 Posts: 2 Location: baltimore, md

i am trying to build a crackle box synth, and cannot find the required (and obsolete) UA709 or LM709 IC. any ideas on where i can pick one of these up? or if not, any suggestions for a replacement?

mosc · Posted: Wed Mar 29, 2006 6:58 am Post subject:

I have never built a Crackle Box, but I've seen them and they are really cool. I've read that replacing the 709 with another op amp doesn't work, but I have not 1st hand knowledge of this. We have a memeber here, Bugbrand, that might know something about this device. I sent him a PM. Maybe he'll chime in.

bugbrand · Posted: Wed Mar 29, 2006 2:27 pm Post subject:

Chimey!

Yeah, cheers Howard - he emailed me through my website - had a quick look on ebay and located some (..search as LM709* - using the asterisk power).

I think there are some sources (N.O.S. stockists) about but I don't know for sure.

YES - they are FUN!

Scott Stites · Posted: Wed Mar 29, 2006 9:01 pm Post subject:

Electronic Goldmine has them listed for $1.95 each:

http://www.goldmine-elec.com/default.htm

HSC has them listed for $0.40 each:

http://www.halted.com

Look around either place - both have nice goodies. I've ordered from Electronic Goldmine several times, they're pretty consistent.

I've ordered from HSC once - they're OK, but maybe prone to three martini lunches? Very Happy

Quantities of a few items got turned around. They also slid an NE571 or two into some NE570's I ordered. But, good prices and a nice selection all the same.

Cheers,
Scott

bugbrand · Posted: Thu Mar 30, 2006 1:16 am Post subject:

Scott strikes gold again - - that's what I'm talking about.!.

But --- Scott, what the hell do you mean by 'three martini lunches'?????? (..nice phrase.!.)

Scott Stites · Posted: Thu Mar 30, 2006 7:15 am Post subject:

Well, the quantities of some items were switched (example I ordered 5 of X part and 10 of Y part and received 5 of Y part and 10 of X part). Not on just a couple of parts, either. Looking over what I received, I had a mental image of some guy getting back from a 'merry lunch' and staggering down the isle, pulling parts and putting them in the bag....

I gently emailed them about it, didn't get a response, and just let it ride - nothing critical, I usually over-order anyway. Jameco, by comparison, would have been on top of it immediately.

I don't *not* recommend them, I just take'em as they come. They do have a nice selection and fair prices, overall. Just don't be surprised (same thing happened to a friend of mine with them).

Cheers,
Scott

Edit: Corrected grammar. Must've had a 3 martini breakfast......

daukterjones · Joined: Mar 28, 2006 Posts: 2 Location: baltimore, md

thanks a bunch mr bugs and scott. i ended up bidding on the metal cans on ebay...its an order of 10, so if anybody needs one let me know, dont see myself using all 10 of them.

bigtex · Posted: Tue Apr 04, 2006 11:44 pm Post subject:

When looking for hard-to-find stuff, or even when just looking for the best price on something that's easy to find, or actually if I'm buying anything at all... I always hit up http://findchips.com first. It searches many vendors at once, and not just for chips. Great site.

dnny · Posted: Wed Apr 05, 2006 12:08 am Post subject:

thank bigtex for the link and welcome welcome

to electro-music forum

Wild Zebra · Posted: Thu May 18, 2006 8:30 am Post subject:

I've got the chip, thanks to dnny Smile

, My question is whats a good sub for the BC547 and BC557 will 2N3904 npn and a 2N3906 pnp work? I have plenty of those and my local shop has outrageous prices. I hate to go there to buy the BC's. They probably won't have em anyway.
Any suggestions would be appreciated

bugbrand · Posted: Thu May 18, 2006 12:08 pm Post subject:

Yup 2n3904 & 3906 will work absolutley fine for this

Wild Zebra · Posted: Thu May 18, 2006 12:17 pm Post subject:

Thanks BugBrand. I'm gonna give the old Schem to Perf a try for the first time. Reckon I need to figure that out sometime and the crackebox looks fairly simple. It may not be the prettiest or smallest layout, but I gotta start somewhere. Give a go on the breadboard and then on to the perf.

thanks I got plenty of 04's and 06's

bugbrand · Posted: Thu May 18, 2006 1:20 pm Post subject:

I think they can almost always be interchanged in whatever project -- the only thing to watch out is that they're the other way round --> if you've got a plan for BC547 and want to use a 2n3904 then turn it through 180degress (and same for 557/3906)

Enjoy the crackle sounds!

Wild Zebra · Posted: Mon May 22, 2006 10:36 am Post subject:

Put this together over the weekend. Pretty cool little noise box. I'm still a total novice (paint by numbers) So I did this one from scratch. Schematic to breadboard (had a little trouble there) to perfboard, and it worked. Sweet. Now just gotta find a nice enclosure. I figure it's working right. It makes a bunch of noise. One pad seems to be the primary noise source and one or two others give it a on-off square lfo effect, but different combo's really start to get it going.

Thanks dnny and bugbrand!

dnny · Posted: Mon May 22, 2006 12:52 pm Post subject:

nice to hear that you had success whit crackle box!
oh.. if i just had little time...

mosc · Posted: Mon May 22, 2006 1:24 pm Post subject:

Congrats on the home grown Cracklebox. As the battery gets used up the characteristis of the instrument change..

bugbrand · Posted: Tue May 23, 2006 2:25 am Post subject:

YAY!

Yes, find a lovely box for it - what are you going to use for the touch contacts? You could make it really big and put metal door knobs on it.!.?.

There's an additional audio output mod here on my web if you haven't seen (..the circuit works wierdy if you try to just take the audio to a jack socket..)

mi_dach · Joined: Dec 17, 2005 Posts: 133 Location: Sweden

Wild Zebra · Posted: Tue May 23, 2006 8:28 am Post subject:

Thanks guys. I'll check that mod bugbrand. I'm now wondering if it's working right. As I said never made anthing straight from schemo. I had a little trouble with the tranny orientation. When touching the pads does each individual pad made a noise? Mine seems to works like this.
1- one pad pretty much makes noise as soon as you touch it
2-another is a on off effect
3-some of the others act like a kind of off switch unless touching combinations.

It just seems like sometimes I get alot of "cutting off" It'll be making lots of noise then I touch a pad and whammo stop.

I don't have any contacts yet except the ends of wire. Well it sounds cool anyway, but I'd like to know if I did it right.

Anyway bugbrand, I was thinking of some larger brass knobs. Make it kind of big.

blue hell · Posted: Tue May 23, 2006 12:28 pm Post subject:

mi_dach · Joined: Dec 17, 2005 Posts: 133 Location: Sweden

I meant connecting the audio output through a buffer, to get a line out, which could go into my mixer. It's not exactly near the mains. Or does the cracklebox contain some weirdness that makes it much more dangerous than, say a microphone, or the computer chassis?

blue hell · Posted: Tue May 23, 2006 1:17 pm Post subject:

Well its all up to you of course, but I wouldn't touch a computer chasis either with wet fingers.

mosc · Posted: Tue May 23, 2006 8:59 pm Post subject:

Wild Zebra · Posted: Wed May 24, 2006 8:20 am Post subject:

Thanks MOSC. Boy, I need to take your advice and use the spellcheck. I read my post again and it was kind of funny. Thanks for the conformation. I messed with it a little more last night. I reckon it's working just fine. Just got to find an enclosure.

I'll post pics.

mosc · Posted: Wed May 24, 2006 8:43 am Post subject:

Hee hee.. Every time I see a post about the Cracklebox, I get mine out and amuse myself with it for a few minutes. Very relaxing. I left it switched on overnight. The battery has run down a bit. It's a different instrument now. Much more soulful.