Wednesday 4 March 2009

OCD Clone



The schematics have been around the net for a while, so I though of giving it a go. I am happy I did because this baby lives up to its name. Really nice fat distortion with quite a bit of sustain...Even the finish came out nicely! The circuit is based around the usual TL072 op amp with two 2n7000 transistors used in the clipping section instead of the usual diodes.

Check out the video for sound samples...i will post the pics of the guts soon.

Tuesday 3 March 2009

Fuzz Face DIY pedal BC108



I always passed on the fuzz pedals hype, thinking it was something to do with the fact that Hendrix used it and nothing more. I did try a few in the past, but always opted for a warmer overdrive type pedal.
Since I got into building my own pedals I started a looking into building a fuzz face, as it is a very simple circuit...I was not impressed by my first few attempts...until I read this excellent article by R.G. Keen on his website www.geofex.com about picking transistors and biasing properly.

http://www.geofex.com/Article_Folders/fuzzface/fffram.htm

Also check out the general guitar gadget version of the fuzz face, where It replaces the 8k2 resistor with a 10K trim, that allow you to bias the transistor properly, also useful to 'tune' by ear if you wanted to do so:

http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=101&Itemid=26

http://www.generalguitargadgets.com/pdf/ggg_ff5_lo_npn.pdf

Another great site to find out about different versions of many fuzz pedals is fuzz central: this is the page about the Dallas Arbiter fuzz face:

http://fuzzcentral.ssguitar.com/fuzzface.php




So after trying a few different combinations I decided to go for a silicon late 60' early 70's fuzz face, similar to what Hendrix used in his last few albums, using two toneful BC108...funnily enough I found out Eric Johnson uses a silicon fuzz face as well, with a BC183, very similar transistor to the one I used.

Of course the finish had to have something to do with Jimi, so I found a great picture and printed the graphics on a adhesive vinyl sheet...I love the results...straight on my pedalboard!


Check out the video for a sample of different sounds this pedal can make!