It looks like you're new here. If you want to get involved, click one of these buttons!
Subscribe to our Patreon, and get image uploads with no ads on the site!
Base theme by DesignModo & ported to Powered by Vanilla by Chris Ireland, modified by the "theFB" team.
Comments
There is a variable volume output as the the gain is rotated (loud -> quiet -> bit louder with OD), and there is a blip at the end of travel, I think the offboard wiring is correct, so I suspect there is a solder bridge somewhere or a misplaced component around the gain circuit.
Time to troubleshoot.......
Adam
However, im certain that its a fault with my build rather than the layout. Id love to be skilled enough to draw up my own layout but Im not there yet.
Here's a link for you
http://tagboardeffects.blogspot.com/2014/05/klon-centaur-with-optional-bass-control.html?m=1
First job tonight - power on and measure some IC voltages. Hopefully that will give me a clue where the error is. I'll go over it again to check there are no misplaced components or solder bridges before re-doing the whole veroboard.
Adam
The only thing I can find not quite right is an almost-but-not-quite voltage on ground connections of two of the IC's (2.1mV, not 0V, for 1st opamp and voltage multiplier.
So if anyone can help me out, I would very much appreciate it.
Here's a couple of build pix.
https://i.imgur.com/e4XtuMd.jpg
https://i.imgur.com/VhvbUao.jpg
https://i.imgur.com/MQd5Gf4.jpg
https://i.imgur.com/tSQCFdI.jpg
https://i.imgur.com/4rBNODR.jpg
The offboard wiring is far from perfect, but im quite pleased with the flip-flop paint enclosure.
Cheers,
Adam
The behaviour of the gain pot is most baffling to me, and i might just try 2xB100k pots instead of the dual.
So is your rails are good on each chip and circuit works almost as intended then get some 72's before going any further. Then see where you are.
By rails, do you mean +ve and gnd connections? If so, would the slightly not 0V likely be part of the problem?
Is that to check for poor solder joins?
Also, i assume then that the 72 is a fet input?
I am at the frustrating stage of knowing a little, but far from enough, to allow good troubleshooting technique. Im getting there, slowly.
Thank you for your help.
Adam
Another thing I do is to take a small section of the board at a time and examine it coordinate by coordinate, as it were. Theres often a "doh" mistake in there somewhere ( at least in most of my builds ! ) Resistor values are a frequent culprit.
Finally check each off board connection several times to make sure there nothing wrongly connected off the board.
Have you also read through all of the posts on the project website ? - I have found that sometimes "verified" circuits don't perform as the originals, and eventually someone will pick up the original circuit tracing error and post it.
Good luck - always fancied a Klon but never made one yet.
I will go over the board again, and your suggestions are all very sensible. If nothing comes up with another check and reflow of solder, i may just build another board and repopulate. And again I *think* the offboard wiring is correct, and unless theres a solder bridge on a pot somewhere (esp on the dual gang gain pot) there must be a dodgy connection on the board itself.
Ive had a look through all 200-odd messages on the tagboard forum, and nothing too useful for my problem. Several people seem to have it working too, so i dont think there's an issue with the layout.
Anyway, back to the solder board (in between other pedals, the current guitar build and amp kit no.2 that is!)
Adam
I know a bit, but not enough to compare circuits (especially as i dont have a 'circuit' of the Klon as such, more a layout of where components are on the veroboard. Its possible to derive one from the other, but beyond my time management skills!)
I shall certainly look at the Fuzzdog version, as you say it might spark a Eureka moment.
Cheers,
Adam