5equencer
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Nov 01, 2024
In October I built a small Eurorack case that I could fit into my backpack to take with me on a trip to visit family in Sweden. After picking all the modules I needed from my main rack, I had 6 HP of space left for a module to control the pitch of my VCO, but the only sequencer I had was a 26 HP baby-8.
To fill that hole I designed this module, the 5equencer. (Huge thanks to Kristian Blåsol from Modular in a Week for coming up with the name.) It’s a simple baby-8 style sequencer with the following features:
- 5 steps
- switch to set the sequence length to 3, 4 or 5
- switch to set the output voltage range to 2V, 5V or 10V (not precise, just within a few hundred millivolts)
- clock input
- reset input
I’m very happy with how useful it is for such a small and simple module. Although it only has 5 steps, I’ve managed to get very interesting sequences out of it by using the EasyEi8ht to control both the step and reset inputs.
Schematic
Download:
Stripboard layout
Download: repository/5equencer-stripboard.diy (0.1 MiB)
BOM
| Name | Value |
|---|---|
| R1, R3, R5, R7, R10, R11, R14 | 100k |
| R2, R6, R8, R9 | 10k |
| R4 | 47k |
| R12 | 680k |
| R13 | 22k |
| R15 | 1k |
| R16-R20 | 22k* |
| RV1, RV2, RV3, RV4, RV5 | B100k** |
| C5, C6 | 10μ |
| C1, C3, C4 | 100n |
| C2 | 22n |
| D1-D9 | 1N4148 |
| D10-D14 | 5mm LED |
| Q1 | 2N3904 |
| Q2 | 2N3906 |
| U1 | CD4017 |
| U2 | TL072 or LM358 |
* Use whatever value gets you the LED brigtness you want, but don’t go below 4.7k to keep current drawn from the CD4017 low.
** ≈2.54mm pitch. Alpha RD901F-20 / Alps RK097 / Aliexpress “RK097N” / Tayda RV9110 / CUI Devices PTN091-H / TT Electronics P091N
Panel
Here’s the template I used to make the panel:
Photos
