Suiseki Phase Shifter Manual

Thank you for purchasing the Suiseki circuit board and panel set. This document includes the parts
list, schematic, a reference layout image, construction notes and operation notes.
Construction Notes:
The attached bill of materials (BOM) lists all parts needed for the board. The BOM uses mostly
Digikey product numbers for reference, but parts can of course be ordered from any supplier such as
Mouser or your favorite octopart.com search result using the vendor numbers. Some folks like to use
all 1% metal film resistors, but it is not necessary. The only critical capacitors are C8 to C14 and C23
to C25, these need to be polyester film types. Note: there are seven 0.1uF bypass capacitors of the
usual X7R ceramic type.
The board is made with a standard hot air solder layer, but soldering with leaded solder is fine.
Similarly, you can use "no-clean" or organic solder, just be sure to rinse the board in the case of organic
solder.
The recommended soldering order is install all axial resistors first. Certain resistors are vertical-
mount: just bend one lead in a "U" such that it points down next to the other lead, then install. Next,
install the three ICs, then transistors and capacitors. These parts can all be soldered with organic flux-
core solder and rinsed in warm water. Be sure to allow sufficient time for the board to air dry.
Note: leave out capacitor C25 for now. It will be installed after the power header JP1 is installed. C25
is a tight fit and it is easier to deal with after JP1 (and R11) are mounted.
Note: four 15K resistors are omitted: R21, R28, R38, R39. These are bias resistors for the
linearizing diodes of the OTA cells. On this version they are not necessary and are not used.
The parts that must be soldered with rosin-core or "no-clean" low residue solder are the pots, jacks
and headers. Pay attention to the panel pots and jacks so they line up flush with the panel board. It is
helpful to check the fit for each panel part. Flat washers between the circuit board and the panel should
not be needed, just be sure to use a washer under each pot and jack nut in final assembly.
The trimpot R27 can be mounted on the top or bottom. It is used to tune the default position of the
phase shift response when no LFO or CV signal is present.
JP1 is a user's choice of 2x5 or 2x8 shrouded header. For 2x5, the header installs in the lower 5 rows
of holes, leaving the top 3 rows open. The 2x8 header of course occupies all holes. In both cases the
header installs on the component side of the board with the notch to the right (toward edge of board).
Once JP1 is installed, go ahead and install capacitor C25.
LED: the LED is installed last, after the panel is installed. Using pliers make a right-angle downward
bend in the leads approx 4mm from the base of the LED with the shorter lead above the longer lead (as
seen before bending). Drop the LED leads into their PCB holes and gently nudge the LED into the
panel hole. Turn board over and solder one LED lead. Adjust the alignment if needed, then solder the
remaining lead. The LED will glow green for positive LFO half-cycles and red for negative LFO half-
cycles when installed correctly.
Suiseki Phase Shifter for Eurorack