My Cornish Style Board, WIP. (pics inside)

[sjaltenb]

hahaha yeah that picture is kinda funny. good thing im in college and the girlfriend just laughs cause she knows she cant say anything 

and yes, thanks to Zedmin FX for providing the DynaComp build!

[Eb7+9]

Questions, criticism, whatever, lets hear it.

you may want to do the whole inside of the enclosure with conductive paint and ground all sides just to be sure you have a good Faraday cage ...
... nice work

[sjaltenb]

Questions, criticism, whatever, lets hear it.

you may want to do the whole inside of the enclosure with conductive paint and ground all sides just to be sure you have a good Faraday cage ...
... nice work

one step ahead of you, its painted with a highly conductive shielding paint from LessEmf.com

[rogerinIowa]

Cornish Hens, Cornish Pixies..... when something  is referred to as "Cornish" doesnt that imply that  it will be tiny? so what gives? just kidding you, I couldnt resist...

that is an amazing amount of work, very impressive!

[cpnyc23]

Most impressive.

Did you design the power supplies yourself? 

-chris

[theblueark]

Quick question, the 9V jacks in the picture look like they are all daisy chained together. What would be their purpose?

[sjaltenb]

those are 4 DC jacks for external FX. they will share a single 1amp 9v power supply. This will power the Wah mostly, but also any external FX, switching boxes, that I need to add will also be powered from there.

Every single other effect has its own AC transformer secondary and  an independent rectified, regulated and filtered power supply to avoid any possibility of ground loops.

I have not updated the pictures, that power scheme is very old. new ones coming soon!

here is the trasnformer all wired up:

[Ben N]

Hooo-eee that is some serious iron!

[sjaltenb]

the czech republic does some fine work! 70 bucks!!!! Not too bad really, the quality is unreal!

15 outputs baby

[mth5044]

There needs to be more pictures stat.

I love this project, hard.

[sjaltenb]

Here is my layout for the PSUs...I think its final. Also im making a few tweaks to the 3pdt bypass and the Adjusticator and buffer pbcs.



and here is jack ormans simple buffer/splitter layout I made for the delay splitter. I'm new to layouts so i know its not great but it should work...i had to put a jumper in there off the transistor but oh well...it makes for a decent layout i suppose. i know i could have just used his layout but i wanted to do it myself 

[Cliff Schecht]

Learn how to do ground fills in Eagle. It's REALLY easy. You click the "Draw a Polygon" option, set the isolate to something bigger than 0 (I use 20 mils for low power, 30-40 for high power stuff) and draw a box around the edge of your board on the bottom layer (pretty much RIGHT inside of the white lines). The isolate just determines how far away the ground plane is from the traces, so tweak to taste. When you're done, right click on the new polygon you drew and name it "GND", which will connect the polygon to the ground connection in your circuit. When you click the "Ratsnest" button... VIOLA! Instant ground fill.

This could especially save you heartache on that first board, your ground is pretty darn weak. And on the second board, it looks like the spacing between a few components and traces is a bit close. For the electrolytic caps going to the resistors, make sure the trace doesn't come to close to the square pads. For the top-left resistor, raise it up a little bit as it's kind of close to the large pads right below the part. Also, on the fourth resistor from the left, the top part isn't connected to anything. In the window editor, make sure that your wires are actually connecting to the parts. The easiest way to do this is to clock "move" and drag the parts around, all of the wires should move with the parts. You can avoid these problems by using a grid of either .1 or .05 inches (.1 is the good default, .05 is for "finer" work like on a microprocessor).

[sjaltenb]

Thanks Cliff!

yeah I did figure out the ground fills but was hesitant to use it on the PSU because the actual layout didnt seem to need it. However I suppose it would be good to have a good strong ground on it... I will change it and post an update

Thanks for catching those mistakes on the buffer board!! I don't know how i missed that one part 

I'll get there one day...

[Auke Haarsma]

Cliff already explained everything you need for the groundpour.

Some more details and explanation can be found at gaussmarkov's site:
http://gaussmarkov.net/wordpress/tools/software/eagle/ground-pour/

[sjaltenb]

PS...Special thanks to Papa for the original layout design for the PSU. It doesnt look like it there but the traces are .4 and the isolation is .25. i am leaving room for a clip on heat sink, thats why there is so much spacing. I need to check the sizes of the electrolytics too... i'm using nichicon 2200uf@25v, then 100 and 470@16v. the others are .1


Here is the input splitter...same design just without the 4th output. This should be a little better...

[Paul Marossy]

It's looking great so far! I would like to build something similar, but I don't want to go thru all the effort. 

[Auke Haarsma]

I'd use a bit wider isolation on the PSU, something like .30-.40. But if you can etch this : go ahead impressive work mate!

[sjaltenb]

thanks auke, probably a good idea!

one thing i was thinking about doing.... I have a ton of extra male/female molex socket connectors. I was thinking that I could place a male socket on each PSU that taps into the 9v output and ground, this way once the entire board is wired up, I could first Test each effect with a battery (by plugging it into the power supply test socket) to make sure everything is working...then disconnect and use the transformer after all seems to be working. It seems this would be a nice way to isolate power noise issues by determining what happens if I use a battery, without having to unsolder a single thing, i could just cut off the AC mains and plug right in....

Seems like a good idea to me...here it is:


Also, here is my Adjusticator Layout and schematic. definitely a work in progress. I just left pads to wire the pots in with. I am using it to control line level rack delay levels for the Send/Returns:

[sjaltenb]

The board is almost up and running. I am waiting on a bunch of PCBs from John Lyons (power supplies and 3pdt switching pcbs)

Today I tried to make sure every circuit was ready to be wired up, doing odds and ends, etc. The EQs still need to be mounted, which will be a pain, and some spare parts for a few fx here and there.

I have used about 200ft of belden paired cable 

The transformer, input/output board are all ready to go, as well as amost every effect. It is hard to think about how the entire thing is routed, really gotta take your time and think about it. Heres the latest pics, the coil of wires on top are for the PSUs-FX, and the other large coil to the right is for all the s/rs, volume, wah, whammy, etc.

Some of the FX circuits are kind of just floating there until I solder the wires, then I will secure them to the board. Anyways, enjoy!





Question: I am going to mount the Power supplies on the back wall, to the left of the in/out panel. Do power supplies themselves "radiate noise" like a transformer does? I think if I have any problems I will just encase that entire area with a metal wall....The closest effect is a GE7 and the delay mixer... Every single wire is shielded to ground

[Auke Haarsma]

impressive work mate! I'm looking forward to the clips and vids of this beasty in action!