Wednesday 14 March 2012

Big Muff clone completed

I've finished my clone of the well-known Big Muff distortion pedal. I painted it with some grey primer and then with a design of Cardiff Bay as I have a vague notion of making myself a range of Cardiff-themed effect pedals. Total cost in parts was around £16-17 and a lot of that is because I bought the extortionately expensive switch from Maplin instead of pretty much anywhere else.

It sounds quite a lot like the original as far as I can tell. It is REALLY LOUD, and is unfortunately not very useful for playing in our apartment as I get the feeling I must be annoying the hell out of the neighbours, even at low volumes.

Next up will be a Small Clone clone. A clone2 I guess. It's a chorus pedal that was used by Kurt Cobain on Nevermind apparently. I've ordered up the parts from far-flung ebay sellers across East Asia, so they'll take at least a couple of weeks to get here, which gives me plenty of time to change my mind and start and abandon another several projects.

Sunday 11 March 2012

Big Muff clone

 This weekend I've been down at Cardiff Hackspace building a clone of the well known Big Muff distortion pedal, first getting it working on a solderless breadboard:

Then I built it on some copper stripboard, but for some reason couldn't get it working. After checking, rechecking and re-rechecking, I finally spotted the problem:

See the problem? No?

There it goes - at one of the points where I'd used a drill bit to break the copper track I hadn't quite broken it completely. Those holes are 2.54mm apart so the bit of copper that was left couldn't have been much more than 0.2mm wide, but it was enough for electrons to squeeze through and stop it producing any sound.

Once that and several other problems were sorted, I brought it home and tried it out. It doesn't sound exactly like the original, but it has a nice tone with loads of gain. Hopefully this week I'll put it in a nice enclosure.

Saturday 3 March 2012

Soldering iron power LED

 For xmas a couple of years ago my parents bought me a nice temperature-controlled soldering station which I've been using to build all my half-completed projects. It works great, but it has one small problem: the LCD display isn't backlit so, at a glance, it isn't obvious that the power is on. This isn't normally a problem but if I'm working on something that means I'm soldering something and then going back and forward to the computer to program an Arduino or whatever, it's possible to forget the soldering iron is on.

And then go to bed.

And then go to work.

And then come home and find out that there's been a 50W desk-mounted heater on for 24 hours and somehow we still have a home and not a smouldering ruin.

The solution to this problem is trivially easy - mount an LED on the front to make it obvious that the iron's on. First thing we need to do is open up the soldering iron and find a power source to hook our LED up to.

 This is the main PCB for the iron, and at the top left is an LM7805 linear voltage regulator that supplies the 5v to power the control circuity. Perfect and has long leads that we can solder to. If you're looking at the front of the LM7805, the three leads are Vin - GND - Vout.

 A quick check with the multimeter to confirm. 

I come to a small problem here - how am I going to solder on the inside of my soldering iron? I briefly consider using the soldering iron itself and then remember that I have a butane powered soldering iron for just these sorts of occasions:

I dig out a 5mm red LED and find my LED calculator to work out what current limiting resistor I need. Looks like 150 ohms will do the trick, which is one of the several values I have. 10 minutes and some dremel action later and we have this:

I should have used some heatshrink, but I couldn't find any. It should be ok like this though. The LED fits in pretty snugly but for peace of mind I might stick some hot glue on the back to hold it in. But does it work...?

Power off

Power on!
Success! And all done before breakfast on a Saturday. Quite good fun in the end, and if it stops me from accidentally burning down the house, well that's just a bonus.