Designing PCBs is hard

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: luketeaford, Joe., lisa, Kent

goom
Ultra Wiggler
Posts: 808
Joined: Sun Jun 07, 2009 8:03 pm

Post by goom » Wed Mar 14, 2012 10:28 pm

I haven't read the whole thread , but it also looks like the two caps above IC4 are too close the IC. The caps will not fit there if they're on the same side of the board.

User avatar
Tombola
Super Deluxe Wiggler
Posts: 1878
Joined: Sun Jan 23, 2011 11:33 am
Location: London, England

Post by Tombola » Thu Mar 15, 2012 2:20 am

@goom - those electrolytics are on the other side of the board, because they'd be too tall to fit behind the panel otherwise - same with the 4015s, because they'll be in sockets - I've had trouble with them in this circuit - some work, others don't.

Jarno
Super Deluxe Wiggler
Posts: 2772
Joined: Mon Nov 15, 2010 6:34 am
Location: Rosmalen, NL

Post by Jarno » Thu Mar 15, 2012 3:32 am

I think routing a PCB is fun, on top of this, I can do it on the couching sitting next to the wife. This helps to both fulfill my social obligation AND get some "work" done at the same time :mrgreen:

But since I make my own PCB's and haven't tried double sided ones (yet), I am limited to single sided. Those can be a bit of a bitch to layout without having to resort to a ton of jumpers, especially with SMT parts where you often can't run traces between pads (I try to use widely spaced thick traces because I use toner transfer). Although mixing SMT and TH helps to step over traces.

User avatar
lazerkind
Wiggling with Experience
Posts: 326
Joined: Mon May 03, 2010 9:16 am
Location: mostly Sweden

Post by lazerkind » Thu Mar 15, 2012 5:41 am

I like PCB routing as well, it is like solving a puzzle or cross word.
Frustrating as hell here and there but very rewarding when you are done :tu:

User avatar
sonicwarrior
Super Deluxe Wiggler
Posts: 3815
Joined: Tue Sep 29, 2009 3:36 pm
Location: Cologne, Germany

Post by sonicwarrior » Thu Mar 15, 2012 10:54 am

frijitz wrote:noise bypassing
Like the noise from electrolytics e.g. in a PSU design?

Btw. AFAIK this layout is noisy because of the electrolytics, right?

Image

C2 looks OK, but C1 shouldn't have a shorter connection to COM than to CT.
Fix would therefore be to isolate the ground around C1 and make a bridge to the ground around C2 somehow if I got it correctly.
Soundcloud
For sale: Jürgen Haible Tau Phaser (MOTM format)

User avatar
nickciontea
brownshoesonly
Posts: 1268
Joined: Wed Feb 03, 2010 10:37 am
Location: Chicago
Contact:

Post by nickciontea » Thu Mar 15, 2012 11:28 am

Image

first board since college. first with eagle, laid manually.
thanks to the people who walked me through all my questions

could be better but I feel good![/img]

User avatar
Tombola
Super Deluxe Wiggler
Posts: 1878
Joined: Sun Jan 23, 2011 11:33 am
Location: London, England

Post by Tombola » Thu Mar 15, 2012 1:25 pm

nickciontea wrote:
could be better but I feel good!
:yay:

User avatar
JRock
InterGalactic Barbarian
Posts: 1767
Joined: Thu Dec 23, 2010 2:29 am
Location: PA

Post by JRock » Fri Mar 16, 2012 12:33 am

Here's the one I did today :tu:
Image

:party:

User avatar
SOFTWIRE
Wiggling with Experience
Posts: 495
Joined: Mon Jul 06, 2009 8:31 pm
Location: Salt Lake City
Contact:

Post by SOFTWIRE » Sat Mar 17, 2012 12:12 am

the last pcb i just finished has 753 components and 2615 pins. hand routed in 2 months or so. i wouldnt ever touch the auto router though.... also i swore alot while making it

Image

User avatar
falafelbiels
still learning to wiggle
Posts: 4356
Joined: Tue Aug 04, 2009 7:15 am
Location: Rotterdamm son

Post by falafelbiels » Sat Mar 17, 2012 6:40 am

SOFTWIRE wrote:the last pcb i just finished has 753 components and 2615 pins. hand routed in 2 months or so. i wouldnt ever touch the auto router though.... also i swore alot while making it

Image
SHIT, I get confused by routing my 10x2 cm PCB layouts and here you are building a time travel machine!

User avatar
Chrome Dinette
Common Wiggler
Posts: 190
Joined: Sun Feb 03, 2008 9:14 am

Post by Chrome Dinette » Sat Mar 17, 2012 7:12 am

Yeah, keep at it, it gets easier, though I don't udually do things as complicated as the example in this thread(I'm doing guitar pedals).

I will use the Eagle autorouter, but always have to move stuff around afterwards. Orienting the components on the board correctly is half the battle.

User avatar
iopop
Super Deluxe Wiggler
Posts: 1073
Joined: Wed May 19, 2010 2:11 pm
Location: Helltown, Sweden

Post by iopop » Sat Mar 17, 2012 7:24 am

sonicwarrior: That's quite interesting, since the PSU in question is specially made for pro DIY audio. :hmm:

On the other hand that PCB is among the cheapest PSUs ($8 incl shipping?) Ive ever found and its easy to build.

User avatar
det3
Common Wiggler
Posts: 200
Joined: Sat Dec 06, 2008 2:15 pm
Location: That One Place, yeah.

Post by det3 » Sat Mar 17, 2012 11:31 pm

Autorouters have their place, sure. I can reliably say that any analog audio design I have done has never been autorouted. However, there are designs like this:

Image

that require the use of an autorouter. That's an entire computer on a 2.25 x 0.825 inch PCB. Ten layers and about seven thousand routes.

Even on that design, I used the autorouter sparingly. I'd route small groups of wires that needed to be the same length or have similar constraints then manually clean them up. Route, rinse, repeat. This is using a REALLY good autorouter too (The successor to SPECCTRA). Once you develop enough technique, you can route quickly and effectively while producing hugely superior boards to autorouted designs anytime.

I also can't emphasize enough that placement is 85% of layout. You need to move everything around to optimize and minimize the trace length while achieving overall design goals.
Detachment 3
Destroy what Destroys You

Post Reply

Return to “Music Tech DIY”