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(post
:title "Stick preamp PCB arrived"
:date (string->date* "2013-01-27 00:00")
:tags '("audio" "pcb" "DIY" "preamp" "chapman stick" "free software")
(figure "pcb-1.jpg" "One of the boards")
(p [Today I received a package from Shenzhen containing ten printed
circuit boards. I ordered a single board through ,(ref
"http://taobao.com" "a taobao store") for only 100,(~)RMB (about
USD,(~)16), but I suppose there is not much of a difference
between the production costs of ten boards and that of one.])
(p [The board is the heart of my two-channel Chapman Stick preamp /
signal router. It includes a cross-over circuit for the bass
side, so that I can partition the bass signal into two frequency
ranges that can be routed and processed independently. It has
three very simple effect inserts (high bass, low bass, and
melody), two buffered outputs (both signals mixed down to mono or
dual mono), and a tuner output (which could be used for an
on-stage monitor).])
(p [The circuit and the board were designed using the ,(ref
"http://www.fsf.org/about/what-is-free-software" "free") programs
,(code [gschem]) and ,(code [pcb]) of the excellent ,(ref
"http://www.geda-project.org" "gEDA suite"). (For some odd reason
,(code [pcb]) is not available through the official Archlinux
repositories; I installed it through the Arch User Repository.)
You can get my circuit diagrams, the PCB layout, and custom
footprints through the ,(ref
"http://git.elephly.net/hardware/stick-preamp.git" "git
repository") I set up for this project.])
(figure "pcb-2.jpg" "Oops.")
(p [The manufacturer only received the exported Gerber files that I
checked with ,(code [gerbv]). Sadly, I didn’t realise that the
silk screen layer would be printed on the bottom side of the
single-layer board, so the text on all ten boards is mirrored. (I
suppose I could get used to saying “TЯƎƧИI”, but “YᗡO⅃ƎM” just
sounds weird.) Now I will have to carefully check the orientation
of the transistors before soldering them onto the board because
I’m not sure whether they have been mirrored when I designed the
board.])
(p [I’m still missing two or three parts (different component packages
and power line filtering), but I’ll start soldering the first
components to one of the boards tonight.]))
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