I scanned this from Silicon Chip from a few years back. The article is a complete project, schematic, pcb layout and parts layout etc.:
http://rockindazza.tripod.com/welcometomyworld/id9.html
Click on tremolo pedal project link

Comments anyone? Haven't built one but my 2.2c is the pcb layout is large design to fit a half rack case but could be redesigned to fit  a pedal.

I also have a copy of that SC magazine floating around somewhere but have downloaded anyway in case I can’t find it when I really need it.  

My 1000/400hz oscillator is based on this circuit.  The output isn’t a perfect sine wave but it’s near enough.  It runs off a 9V battery.

One thing I’ve never understood about SC guitar related projects, is that they never seem to look into what the standards are before designing.  For example, this one uses a 12V supply instead of 9 and they didn’t use a stompable type of switch.  Their guitar amp project (forget which issue that was) didn’t incorporate the traditional mid scoop which compensates for the naturally middy sound of guitar pickups.  

Never the less, that’s not to say this unit wouldn’t sound any good.  It might even sound fairly ace.  I’ve thought about building it a couple of times but never have got around to it.  

SC are now also a web based magazine.  They charge $ to view projects like this one, so don’t be surprised if they ask you to take it down.  

Every one else download while you can.

I’d be interested to read a build report, especially if it works OK on a 9V supply.

Quote from: RobB
One thing I’ve never understood about SC guitar related projects, is that they never seem to look into what the standards are before designing.  For example, this one uses a 12V supply instead of 9 and they didn’t use a stompable type of switch

The jaycar guitar projects are like that too.  The designers have difficulty relating to how their designs are actually going to be used, prolly 'cos they're not guitar players (or even musicians) ....