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Table of contents

further links:

general discussion

https://www.muffwiggler.com/forum/viewtopic.php?t=195208&start=0

http://www.psycox.co.uk

BOM:

make sure you know which PCB Version you have

for SY-1M  rev.1 (sold in Arpil 2018) MOUSER BOM https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=1305 e9618c

or use rev.1 MOUSER/DIGIKEY BOM Cross-reference : VIEW IN GOOGLE DOCS

for  rev.2 (sold since 05.September 2018) https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=b83daa5bf6

for rev.1. and rev.2:

add 2x Multiturntrimmer for CV V/Oct or 4x if you want multiturn for V/OCT Midi too.

order: T67W-100K from tme.eu or from mouser:

Mouser-Nr.:

858-67YR100KLFTB

rev.1 customers from europe:

for both versions: (not in BOM)

Important files:

rev.1 Build doc. DOWNLOAD

rev.2 Build doc. DOWNLOAD

Midi Reference doc. DOWNLOAD

Board Reference sheet:  sy_1m_board_reference_sheets_825.zip

Original Schematics Pearl Syncussion: schematics.pdf

Usage VCO modes:

A VCO 1 only 
B VCO 1 modulates VCO 2 frequency, the latter is routed to the VCF 
C Both VCO to the filter but VCO1 at reduced level. 
D EG 1 modulates VCO1, EG2 modulates VCO2. Both VCO to the filter 
E VCO 1 modulates VCO 2 which has a sawtooth wave. VCO 2 to VCF 
F Noise to VCF, no oscillators

HOWTO SMT ASSEMBLY:

my addional build tipps:

•  the first provided BOM was wrong, the included FLAT pushbutton (this ~7mm height switches aren´t needed), the correct 2 pushbutton switches (~12mm height ) are included for the first batch. (ordered until April 2018)
•  the groundpads are not easy to solder, i prefer to use leadfree soldercore for this pads (clean this pcb sections after soldering)
•  Change R63  to 1K to get the best noise gain or use a 2SC1815 like in the original  (with reversed pinout and a 10K resistor for R63)
  
  
  
•   for calibration: R10 and R42 must  be grounded or the VCO frequency goes down and down  - also you can try to trigger with a sequencer while calibration the syncussion.
  

Power Input

the BOM use a 2,5mm middle Pin powerconnector  BUT the most powersupplys use a 2.1mm middle pin, you can´t use a 2.1mm powersupply with a 2.5mm connector.

the most webshops have more 2.1mm powersupplys in stock and 2.1mm is the defacto standard.

middlepin is +

Spec:  DC 9V output with 300mA or more, 12v Powersupplys works too, but the regulators only waste the voltage to heat

Pinheader assembly

•  solder one the pin header to the pcb
•  shorten the pin stripes by 1mm-2mm
  
  
  
•  plug the pin stripes in the hader, it has to be full in it - like this:
  
  

•  now attach on the top a further pinheaderlike this: (the same is on the right side with the 3pin header,  the 4pin header dont must be shorten because the header don´t have the same height.
  

before you solder the pinheaders to the top pcb

make sure the pcb is flat and do not bend.

make sure you solder the MIDI channnel switch, midi input jack and power input to the bottom side like :

if you have everything soldered and you´re ready for the first test, make sure all IC´s and THT Trannys have the correct orientation, dont install the ATMEGA for the first test

please doublecheck the polarity of your powersupply, middle pin is +

set the powerswitch to off,

connect the powersupply

Changes/mods

• the original Syncussion use a 2SC1815 in the noise section, i tried in one build this type (with reversed pinout) and a 10K resistor for R63, the result is the same like with BC54,

no difference in sound, gain etc.

• use Multiturn trimmer for CV V/OCT and Midi v/oct

Power Modification

install on new build:

preinstall in case your coil makes hizz/hum: (click to enlarge)

Image AddedImage AddedImage AddedImage Added

Dustover

https://www.diysynth.de/?cat=c17_Staubschutzhuellen-Staubschutzhuellen.html

Dustcover mats: 

http://synthronics.de/dust-covers_syncussion_sy-1m/

Gallery