Buchla 208 Clone

few words from my side about the 208 Clones.

At the moment are 3 clones on the DIY Market, the first was the 208R from Roman.F (the Black Corp Owner) which was sold in the E.M.S (electro music store) and its still available there. (208r v2)

Since few years is the 208P available from papz (Constantin) - (Portabellabz.be), this version fixed 99% of the issues of the 208R.

Atm. is the 208X on muffwiggler in planning from boobs, but this device isn't released yet and I prefer to wait.

Some new PCB versions are planned which are easier to build, except you have enough experience in the 208 builds.

On this pages are summaries and few tips/tricks for you

Custom panel for my 208P:

original 208 Version:

BOM:

BOM for 208P

Portabellabz_208p_BOM_by_AshtrayWasp-2.xls

BOM from Roman for 208R

https://electricmusicstore.com/blogs/build/12614717-stored-program-sound-source-model-208

Build Guides:

208R Buildguide:

https://modularsynthesis.com/roman/buchla208v2.1/208spss.htm. (black pcb version)

https://modularsynthesis.com/roman/buchla208v2/208spss.htm (earlier version)

208P Buildguide and Muffwiggler Page

208p build thread (papz's PCBs) - MUFF WIGGLERwww.muffwiggler.com › viewtopic

also read the page: http://www.portabellabz.be/208pcbfaq.html

on Portabellabz.be find you many infos and build notes for the 208P. (backup: 208 build notes_final_02-2021.pdf)

General links to shops or infos:

contact me if you are looking for an assembled version 

https://www.samodular.com  > Cases and parts

http://www.portabellabz.be/208pcb.html > PCBs 208P

https://electricmusicstore.com/collections/all > 208R and more

card12 - improved reverb card: New Buchla Card 12 - contact Boops by email or PM on muffs. (40euro in 2020)

card12 guide: https://modularsynthesis.com/roman/boops_208_card12/boops_card12.htm

card12 BOM: My New Card 12 Mouser BOM. New_208crd12-1.pdf

Schematics:

schemas_208.zip

PCB Pics:

cards-2.zip

Tips and Tricks 

Sequencer LED Resistor: the resistor is at the mainboard panel side, you can't change the 5 resistors without removing the Frontpanel.

Tip: install milled headers at the rearside of the mainboard and easily swap the resistors:

Vactrols

The Vactrols on card5 must be selected to have the correct/or your preferred AM/FM Sound. (look at https://modularsynthesis.com/roman/buchla208v2/208spss.htm)

Trick: use milled pins from an milled IC socket or buy this separately, bend the Vactrols legs and cut them to the same length - minimum on bottom of the vactrol 5mm - install the pins IN THE Vactrols legs/pins - THEN install it to the pcb.

the pcb don't have on both pcb sides solder pads - which makes it too complicated to install the pins at the pcb and later the Vactrols.

now you can easily swap the Vactrols - when you have finished the selecting just solder carefully each vactrol to the pin (just in case you move the 208 very often, to avoid that a vactrol get loose)

Vactrols - card5 cable 

Here´s the ultimate way to swap the Vactrols without removing the card5, in addition to the above trick, 

buy MTA156 headers and sockets or molex 156 sized pins and connect it with a 10-15cm cable.

install temporary duct tape at the card5 bottom side - then you can drop the card5 pcb on top of the 208 pcbs while you remove the vactrols.

10K resistor for routing/card12 output mod

install 2 milled pins as shown above for the 10K resistor at the Mainboard from the rearside, this make changes later easier when you want install a different card12 (https://modularsynthesis.com/roman/boops_208_card12/boops_card12.htm)

Build notes from me: