Things With Strings

Last year, I snapped up a Vox Pathfinder 15 (non-reverb) combo amplifier from ebay. The seller was a charity shop, and the amplifier was listed as "untested", so I was taking a bit of a gamble, but figured I'd have a good chance of being able to fix it it it wasn't working, and cosmetically, it looked almost mint. When it arrived, I plugged it in, and as you guessed, it was not working. Barely any sound, and what sound there was was horribly distorted. One thin I did notice was the the power on LED was not aligned correctly with the hole in the back panel, so I did quickly took it apart, and realigned the potentiometers and LED indicator, but didn't have a look in detail at the circuit. I put it back together, but the problem remained. My guess was that the problem was the famous "cambridgitis" (just google that term and you'll find all about it). Basically, a problem where the optocoupler that controls the tremolo circuit fails. A common failure...

After the success of Pete's Bazz Fuss  I figured it was my own turn. I've only ever used stripboard in the past, but wanted to have a go at building a circuit on perfboard instead, so wanted to choose something relatively simple for a first go. The circuit I chose was the EHX™Muff Fuzz™ which despite it's name os more of an overdrive than a fuzz type effect. I drew up my own perfboard layout as below, taking care to make sure the components could be connected easily when soldering. Soldering up was relatively painless, and I was quite please with the neatness. You can see from the pic below that it is a mirror image of the layout above. I used 2N5088's for the transistors and 1N60P for the diodes. The picture below shows the component side of the board prior to shortening the transistor legs.  It worked pretty much straight away to my relief, and sounded OK, so I boxed it up in a 1590A sized box (always a painful process) and here is the f...

OK, what's this got to do with guitars and stuff? Well I've made a couple of DIY effect pedals in the past, and it's something I've been intending to do again once I'd got a bit more free time. This time I've decided I won't be inhaling those nasty fumes from my soldering activities! I was looking at my ever increasing scrap heap of old parts when I had an idea to convert an old computer power supply into a solder fume extractor. The idea being to remove all the internals (salvaging useful parts of course) leaving just the fan, then hook up a DC power source add a switch and pack the space inside with filter material. Pretty easy project really. One thing to note was I had to reverse the fan because it was blowing air out initially and I wanted the reverse. It's  amazing what stuff you find inside. Here are just a few of the salvaged parts some of the salvaged parts I added a DC jack where the power cord used to be. DC jack for wallwart ...