Hey all
here's a layout I did of jok3rx's blacker forest, which is a jfet version of the bogner uberschall.
Yes, I spelled vicous wrong. No, I didn't intend to. I was just so excited to be laser etching.
I also etched the tone stack knobs in backwards order. Ah well.
Mispelling and graphic layout were the least of my challenges on this one.
I did the box ages ago, when I first saw Jim's post elsewhere about the jfet uberschall. I intended to build it using an etch for through hole parts, but I just never got a good etch. Time marched on.
I started doing other things, and recently felt confident enough in my layouts to do an smd version of his circuit. While I was at it, I decided to combine the boost and the mids mods into one switch so they would come on at the same time for leads. Went pretty well over all.
Got the pcbs made, and populated, and then it didn't work. Turns out that during my layout shenanigans I used a bad pinout on the jfets, but fortunately, I could just rotate them mismatched to the pads.
Then it fired up! And sounded amazing!!
But the squeal... dear lord, the squeal, it was heart rending.
I tried all kinds of things. Shielded cable, cap changes, resistor changes, buffers, etc. A few things helped but nothing fixed it. I thought, "maybe I routed those traces too close. Maybe I shouldn't have used a ground plane. Maybe the ground plane should have only been on one side of the pcb." All kinds of things went through my head, on multiple nights, at 2am. Or later.
Then while I was in there swapping out caps, I realized I put the treble pot where the bass pot should be. So I decided to move it and boom. There it was.
I made this layout to match the box (almost), which I had previously stuffed with pots and a footswitch. But I never checked the values of the pots once they were in. Turns out they're from an earlier version of the schematic, not the one I used to do my layout. Damn it!
Changed them to match the schem I used for my layout and now most of the oscillation is gone. I still get some at the extremes of vol settings but its so much better...
I might update this pcb (and the box) when I get a chance since there's a few things I'd change now that I'm older and very little wiser, but overall I'm pretty happy with it!
(http://i1194.photobucket.com/albums/aa361/wgc2005/Guitar%20stuff/viscious/visciousbf03.jpg)
(http://i1194.photobucket.com/albums/aa361/wgc2005/Guitar%20stuff/viscious/visciousbf02.jpg)
(http://i1194.photobucket.com/albums/aa361/wgc2005/Guitar%20stuff/viscious/visciousbf01.jpg)
Awesome job, Jim, love this one! It sounds killer with a tube screamer at low settings in front of it.
Thanks for looking, have a great weekend...!
Great work! I love the layout. Extra points for switch-mounting the board.
With rock and roll, you can misspell anything and it's OK. It's not a mistake, it's artful and loaded with esoteric meaning.
Just tell everyone it's a portmanteau
vi·cious adjective \ˈvi-shəs\
: very violent and cruel
: very dangerous
: having or showing very angry or cruel feelings
+
vis·cous
\'vis-kəs\
adjective
having a thick, sticky consistency between solid and liquid; having a high viscosity.
"viscous lava"
=
Viscious
Seems like a cool name to me 8)
Ha!
Thank you for the kind words and support of my misspelling, gentlemen. I would say its apt, and I learned from it in more ways than one. I had at that time recently learned to powder coat, and was only just working out the issues with laser etching powder.
No regrets!! Onward, upward... ;)
Btw I wanted to mention that in the future, I think I would do the 3pdt so the led is in the center pole, to give more separation between in and out.
Bean's std wiring is great, but if you have a squealing pedal, it might be worth putting in on pole 1, led pole 2, and out at pole 3.
There's not much distance otherwise, and I think it can easily contribute to oscillation with high gain circuits.
Killer! I was checking out some Uberschall vids. A lot of shredding goin' on.
Thx mark! I've never played through a bogner so I don't know how close it gets, but I like it! It seems every time I really dig someone's tone theres a bogner amp involved.
I dig it! Mistakes are just learning experiences and believe me, I've learned a LOT! ;)
What wire are you using there?
Thx man! That's why I post this stuff, hopefully someone else can avoid a problem if I've already tripped myself up and hopefully figured out the issue. But cool to see nice comments too.
I think this is tayda wire, not really great stuff, but hate to throw it out. I like amphenol ribbon or the pre bonded stuff from guitar pcb or small bear a lot better.
I hope I didn't seem like I was saying you made a lot of mistakes. I meant that I have made a lot of mistakes myself. But yeah, learning from other people's mistakes can definitely save you some headache as well!
Thanks for the reply on the wire. I'm still on the hunt for some good ribbon cable but I guess the search continues.
nah, didn't take it that way at all. But I did make a lot of mistakes though!
I really like the amphenol spectra bond 3 conductor. mouser 523-111-2699-988
Just now saw this... :P Damn cool Billy!!
That looks like a killer sounding thing... funny fact is that yesterday while hanging at the local music store, they have received an Uberschall and a Shiva.. i would'nt mind owning any of those 2 amps.
JOK3RX, i might send you a pm....
Rej
Love it, and I love the misspelling. It makes perfect sense.
Thanks gents! I really appreciate the kind words.
So much has happened to me in the months since I finished this that it feels like I finished this ages ago.
It is a great sounding thing, and I would love to see a Canadian/uk/jok3rx coalition build! Hint hint.
I have been playing around with the circuit in diptrace here and there and may do another spin sometime soon just to satisfy my ocd.