Im finally a dependent

Started by Seven64, April 25, 2012, 03:01:34 PM

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Seven64

Etched my first pcb today.  I need to harness my excitement and take my time drilling but I'm pretty proud of it.  I only had to cut one trace.  I think I need a better printer because it won't go over 300dpi....so the transfer quality kinda sucked.

It's a zombie chorus rg keen layout


rousejeremy

You got all the text in there on your first try? Awesome!
Consistency is a worthy adversary

www.jeremyrouse.weebly.com

Seven64

it was technically my 5th try with this pcb.  i havent taken another shot at it since last july.  I tried to transfer it 4 times, 3 using the magazine method and once using photopaper.  i could never get a good transfer.  i ordered some pnp blue about 6 months ago, but had 1/2 the day off today and decided to give it a shot.  the pnp blue was super easy to transfer!

Mark Hammer

You,re gonna need to take a dremel bit or a utility knife to some of those areas and create a bit more of a gutter between traces for "insurance", but all in all, not bad.

Seven64

Yea I was wondering that.  Is there still a link somewhere to your tick fix for this layout?  I have searched everywhere but it seems to be down for me

Mark Hammer

Can't find it myself, either, and I'm probably pondering a different solution now, some 10 years later, anyways.

Here's what you ought to do, though.  Make sure you use a low current/power chip for U3.  That could be a TL062, a TL022, or an LM358, among your choices.

You can see a wire jumper situated between R16 and C8 on the parts layout.  That connects up V+ to pin 8 on U3.  Replace that jumper with a low value resistor; anything from 10R to 47R or so.  Run a 1-10uf cap from pin 10 to wherever the nearest ground point is.  Naturally, the + side of the cap goes to pin 8.

That will provide some decoupling and isolation such that when the LFO suddenly draws current to produce a square wave, there will already be some reserve current in that added cap, such that there won't be enough overall current draw to produce a spike in the audio path.  Plus whatever current it does draw will be lowpass filtered by the added RC network.

crazy8

Nice board, and 5th try really isn't that bad. Can't make them myself anymore, (shaky hands) makes shredding a little difficult too.  :icon_sad: (Gotta keep my hobbies). I just get my pcbs from pcb solutions . They don't get upset about my small orders.  :icon_lol:
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