First Pedal Started - Just Now Finished - the Ceriatone Centura

Despite the number of clones on the market, the original Klon Centaur remains an extremely expensive pedal to buy with originals approaching, or exceeding, the $9000 mark. The "affordable" Klon variant from Bill Finnegan seems to run anywhere from $700-$800 (used) and over $1500 (new). As I mentioned in my Tone Geek BFK build entry last September, the very first pedal I tried to build was a Klon Centaur Clone - the Ceriatone Centura. I'd picked up the kit intending to use it to help my son get his electronics merit badge in Scouts. To say that the build was not "entirely successful" would be a bit of an understatement. I'd tried to populate a second board, but received similar poor results. My debugging skills at the time were poor, so I decided to have one last crack at it...

As you can see from the image above, the Ceriatone follows the layout of the original Klon (including jumpers) fastidiously. Since all of the components from the original kit were already consumed, I went to my personal parts bin to fill the PCB. I went ahead and used a few 5% resistors, since the original Klon Centaur only used a few 1% metal film. This version has more metal film resistors than the original, but it is what I had in the parts bin. A lot of the film capacitors are Panasonic, but I had to substitute a couple of Kemet and one silver mica capacitor in for the missing film capacitors. I have another board that I may try and go completely old school on if I can find another enclosure for cheap. The electrolytic capacitors are all Nichicon, and I went ahead and upgraded the TL072 op amps to the "IP" rather than the "CP" version. The diodes are 1N34A with a forward voltage as close to 0.35V as I could find (I think one is 0.354V the other is 0.362V)

Because this is a tight board is spots, I was fastidious in soldering it. I don't often show the "back" of a board, but this time around, I am. I'd been super careful to make sure I didn't have any inadvertent shorts. I was super careful and laid out the LED so it would fit through the hole in the enclosure, and then went for the "light on" test... and... nothing...

At this point I knew something had to be seriously "up." I'll chalk the first failure of this board up to my not knowing what I was doing. The second failure was likely a result of re-using some components, but a third failure? For a board and pedal that aren't cheap and have a pretty good reputation, it just didn't sit right. I'd posted trying to get some thoughts from the troubleshooting team at PedalPCB, and the first questions were around voltage, where the sound was dropping out, etc. 

I realized at this point I hadn't done a sound test so I could start doing an audio trace, so I decided to go ahead and get that going. I plugged in the pedal and guitar and went to play, and was just about blown to the other side of the room - which happens when you crank the Klon all the way up and don't realize that it is not only cranked up, but on and working!!! I clicked the switch, and the tone went back to normal bypass mode. I then clicked again, and the pedal was clearly working - the gain, treble, and output controls all responded normally (and honestly sounded great). In fact, the only thing not working was the LED, so I had another look at the LED marking on the silkscreen and grabbed a spare LED.

Looking at the marking on the silkscreen, I realized it was entirely possible that I just had the LED in backwards. I therefore took a spare LED and touched the leads in the opposite polarity to the installed LED - and it lit right up... well... I feel sheepish...

It was then just a simple matter of boxing up the PCB into the enclosure. I went ahead and updated the grounding just a bit. The original Klon design grounds everything to the board itself. The Tone Geek BFK design beefs up that grounding, but still grounds everything to the board. I'd sold my BFK to my guitar teacher and he'd had a grounding issue with the pedal which I fixed by further beefing up the grounding and essentially using a star ground to the input jack like I use on, well, literally every other pedal I've built. There was then also the small detail of finding where I'd put the enclosure's back plate and screws, which took a little bit to find, but found they were!

The upside is now I have a beautiful looking and sounding Ceriatone Centura pedal in the gold flake and the monkey of still not having the first pedal I'd tried to build working is off my back! The knobs are the originals that came with the kit, though the switch is different and the components are all new. The PCB is an original Ceriatone, just not the one that originally came with this enclosure, so it isn't "numbers matching" if anyone cares about such a thing. I'll likely use the one on my personal board at home as transporting this beast takes care and planning. It's roughly 2X the size of most of my other pedals, and board space is always at a premium!