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[software/elephly-net.git] / posts / 2013-01-27-preamp-board-arrived.markdown
1 ---
2 title: Stick preamp PCB arrived
3 tags: audio,pcb,DIY,preamp,chapman stick,free software
4 ---
6 ![One of the boards](/images/posts/pcb-1.jpg)
8 Today I received a package from Shenzhen containing ten printed circuit boards.
9 I ordered a single board through [a taobao store]( for only
10 100 RMB (about USD 16), but I suppose there is not much of a
11 difference between the production costs of ten boards and that of one.
13 The board is the heart of my two-channel Chapman Stick preamp / signal router.
14 It includes a cross-over circuit for the bass side, so that I can partition the
15 bass signal into two frequency ranges that can be routed and processed
16 independently. It has three very simple effect inserts (high bass, low bass,
17 and melody), two buffered outputs (both signals mixed down to mono or dual
18 mono), and a tuner output (which could be used for an on-stage monitor).
20 The circuit and the board were designed using the
21 [free]( programs
22 `gschem` and `pcb` of the excellent
23 [gEDA suite]( (For some odd reason `pcb`
24 is not available through the official Archlinux repositories; I
25 installed it through the Arch User Repository.) You can get my circuit
26 diagrams, the PCB layout, and custom footprints through the
27 [git repository]( I
28 set up for this project.
30 ![Oops.](/images/posts/pcb-2.jpg)
32 The manufacturer only received the exported Gerber files that I checked with
33 `gerbv`. Sadly, I didn't realise that the silk screen layer would be printed on
34 the bottom side of the single-layer board, so the text on all ten boards is
35 mirrored. (I suppose I could get used to saying "TЯƎƧИI", but "YᗡO⅃ƎM" just
36 sounds weird.) Now I will have to carefully check the orientation of the
37 transistors before soldering them onto the board because I'm not sure whether
38 they have been mirrored when I designed the board.
40 I'm still missing two or three parts (different component packages and power
41 line filtering), but I'll start soldering the first components to one of the
42 boards tonight.