Taking my first steps in DIY Audio
Sat 30 November 2013
My first step into the world of DIY Audio
Bird droppings and solder
In 2008, over 5 years back, I decided that I needed to take some inspiration from the numerous issues of Make Magazine that had been piling up in my cupboard.1 A trip to the local electronics market in Chennai and I was duly equipped with a 25W soldering iron, perf board, solder, and bits and bobs like resistors, capacitors and op-amps that I'd use to make my first project - the TangentSoft Cmoy headphone amplifier tutorial2.
Unfortunately, my several attempts at soldering practice on the perfboard resulted in joints that looked more like bird droppings than the shiny joints emphasized in all the DIY tutorials Duly disheartened, I put my soldering iron away, resigned to the fact that soldering might just be a skill beyond me.
Fast forward 4 years, and it's 2012 now. A slow patch during work and the old bug bit again. This time, I thought I'd make things easier for myself by working with a professionally designed PCB (and instructions that I could follow). A quick search on Ebay and I placed an order for the Banzai Cmoy headphone amplifier3. A week later, the kit arrived at home.
Not wanting to spoil the high quality PCB provided in the kit, I thought I'd practice on the perf board lying at home first. Again, I hit the same issue of dirty solder joints. The kit and all the paraphernalia went back into the cupboard for a second time.
Carpe Diem, Solder!
Last week, I decided that enough was enough.
What was the point of spending USD20-odd on the kit if I wasn't even going to attempt it, bad as it might turn out. I started off small, by trying to solder 1 resistor on to the PCB. To my surprise, possibly due to the better quality of the copper contacts on the PCB, my solder joints looked quite close to the shiny, round joints emphasized in DIY electronic tutorials everywhere. Emboldened, I sat for over 2 hours straight and ended up soldering the whole kit! Even the dreaded DIP-8 socket, and that too decently!
Switching on the the amplifier for the first time was really exciting (and scary). I was dreading that I might have made some cross-connection somewhere and the resulting short-circuit would blow up the capacitors or the op-amp. Once I was confident that there was no burning smell, I connected the amplifier to my PC's audio out and hooked up a cheap pair of earphones that I had lying around. I was really really surprised to: 1. Hear music coming from the earphones 2. And that it sounded great!
The only niggle (and a significant one I think) about this kit was that though its advertised as being able to fit inside an Altoids tin, there was no way that (atleast) my PCB would do so. I ended up wasting another 2 hours trying to make holes in an Altoids, and then dealing with the wires coming loose, connectors breaking etc., as I tried to squeeze the PCB and the batteries in.
Final thoughts
Putting together this kit (with relative ease), I did wonder why I had (and still) struggle to create a proper solder joint on the perfboard I have lying around. I put it down to 2 things: 1. The quality of the copper contacts on the Indian perfboard I use is really really poor and thus doesn't help in letting the solder flow smoothly 2. The quality of the solder I use also might be at fault. The joints I made on this PCB with my Indian solder were dull and grey, whereas the solder provided with the kit produced shiny, siver joints
On this kit, my views are divided. The PCB was definitely of high quality but not being able to fit everything (as advertised) into an Altoids tin was a bit of a downer. This PCB also uses a lot of fiddly (and thin) wires to hook up the switch, and the input and output jacks. This was a big pain because the wires kept coming apart (despite the solder joints). I must have resoldered the wires atleast 4-5 times. TL;DR, if I were to go for another kit4, I'd definitely choose one that ensured all electrical connections were PCB-based.
I was so chuffed that I could actually solder (and make something workable at the end), that in my (over) enthusiasm, I've gone and ordered another 4 different PCBs. God knows I have no need for 4 headphone amplifiers around the house, so my friends and family can expect a(n) (unwanted) gift coming their way soon!
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I have been a subscriber to the magazine since Issue 3! I'm very ashamed to say that except for ogling the projects and tools in the magazine, I've not started a single project yet ↩
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I'd recommend that anyone starting out in electronics, go through the very useful video tutorials on the TangentSoft site ↩
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Looks like its been discontinued. Both the Ebay listings and the company's site have vanished ↩
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I really like the kits provided by Fred's Amps. These are also sold on Ebay (if you prefer the comfort) ↩
Category: Gadgets