Building the Christine oscillating fuzz PCB

[Taylor]

Hmm, nothing sticks out. Maybe if you post a picture somebody will see something that looks suspect.

[ckyvick]

Here are some pics, click images to enlarge.
http://imageshack.us/g/204/dscn0473u.jpg/

[ckyvick]

Swapping out the chip fixed the problem. Oscillations galore!

[Taylor]

Interesting - you swapped for a different part number, or just a different IC of the same type?

[ckyvick]

It was the same type as the other one.

[ckyvick]

Made a demo since I can't find one anywhere I used my rc-2 to loop a riff for the first two minutes then I turn it off and mess with the oscillations-

[Taylor]

Great video! Thanks for doing that.

[wizardsofzen]

just completed my Oakley Sound Systems TM3030 (Roland TB-303 Acid Bassline CLONE) ....
heres a short recording of it with the Christine Distortion

http://soundcloud.com/wizards_of_zen/oakley-sound-systems-tm3030-1

its using the tame chip... i should have a new recording later with the nuts chip

[Taylor]

Wow, that sounds great. 

[wizardsofzen]

@Taylor - thanks!

now heres something slightly different... i recorded around 30 minutes using the Christine, but this time plugged into a 2 toys...

Casper Electronics - Drone Lab V2 passed through to Korg's Monotron, then out to the Christine...

these tones are raw and very loud.

http://soundcloud.com/wizards_of_zen/mini-hook-up-ham-jam-01-8-9-11

[Taylor]

Link doesn't seem to work for me.

[turunturun]

Just finished the christine and all I can say is wow. upon first use I thought it was sort of a less refined fuzz factory and was a bit underwhelmed, but then I played with it a bit and really started to figure out how all the knobs tend to interact and have started to get some VERY cool sounds out of it...and it has an undeniably unique flavor/character.
I am now wanting to build about another two so I set and forget a few of them on my favorite sounds and then put them in a GCX or RJM switcher to have patch recall. A couple settings are extremely unique. This is with the 4049UBE. The 4049BCPG buffered chip was out of control and mostly unmusical in my build, but then I only gave it about 30 minutes in court before swapping back in the UBE and it took me at least 2 hours to get a feel for where the tones are with the UBE so maybe it deserves more study.

SUPER PCB taylor!!!! I....MUST....GET....MORE....!!!!!

[Taylor]

Cool! And my props as always to The Tone God for the great circuit.

The buffered chip is definitely very crazy and for a lot of people, unmusical probably describes it. Just a matter of taste - I think someone earlier said that to him the unbuffered chip was way too boring, so different strokes and all that applies well here. 

[mthibeau]

I can't get my build to work, it lights up and the volume and tone seem to do something, but there is no fuzz and the whole top row of knobs don't do anything I can hear.

I have swapped out the IC, no difference.

I did mount the pots all backwards, and it got a little sloppy removing them and putting them back in the right way (not all, but some of the inside of some of the PCB holes came out with the pot post). Do I need a new board?

I am pretty new at this, but I have built 4 veroboard projects already and they all work. I thought this would be much easier using a PCB.

Any ideas how to go about troubleshooting it? Or should I just order another board and re-try later?

- Thanks,
- MikeT

[Taylor]

Hi Mike, my guess would be that the pads got destroyed when desoldering and lost their connection to where they need to go.

If you have a multimeter, set it to test continuity and look at where the traces go from the pots. Test for continuity from each leg of each pot to where the pad is going. This will help you locate what's working and what isn't. If you find that a particular pad connection isn't working and you can't get the pad happening right, a kludge solution is to run a wire from the pot to wherever it's going.

I can't really answer whether you should get another board since there's sort of a conflict of interest there. 

If you don't have a multimeter, definitely get one! It will be indispensable for building and debugging.

[mthibeau]

Cool, thanks Taylor, I have a multimeter and will check that tonight.

- Mike

[Taylor]

Another thing to check is to measure voltage at lug 1 and lug 3 of the power pot.

[mthibeau]

I tested continuity on the pots through the traces, found one that seemed iffy, but I was able to put some more solder in there and it's now working.

But that didn't fix it.

I have 3.1v on lug 1, 2 and 3 of the power pot.

- MikeT

[Taylor]

I have 3.1v on lug 1, 2 and 3 of the power pot.

- MikeT

Regardless of how the knob is set?

[mthibeau]

I have 3.1v on lug 1, 2 and 3 of the power pot.

- MikeT

Regardless of how the knob is set?

Sorry - tested it again

lug 1 - turned all the way down = 3.5v, all the way up = 5.6v
same for lug 2
lug 3 - turned all the way down = 3.5v, all the way up = 0v

I may have been a little light with my solder connections for my IC socket, I may add a little more to some of them and test again. I took a couple of pictures of the board all built up, would that help?

Thanks again,
MikeT