Random*Source SERGE DSG mk2 User manual

RANDOM*SOURCE
RANDOMSOURCE.NET 1
Serge Slopes (DTG)
SERGE Slopes (DTG)
2“ DSG mk2
Slopes is a 2” wide version of the Dual
Universal Slope Generator mk2 that is
designed to cover both oscillator / audio as
well as clock generator and envelope duties.
All Random*Source Serge modules are
brought to you under license and in coop-
eration with Serge Tcherepnin.
The power of the DSG mk2
This 2” version of the Dual Universal Slopes
Generator features a cycle switch and an
1V/Octave input for the left side for easy
use as an oscillator (that tracks over a bass
range of up to 4 octaves or more). Best
tracking is achieved with the Rise set to
max and Fall controlling the pitch. The right
side is essentially identical except for those
extras.
Outputs are the normal (unipolar / DC)
output (white) and a gate output underneath
the pulse width of which depends on the
ratio of the rise and fall of the normal output.
Patch the red (GATE) out into TRIG IN on either side for cycle mode - of course the left side can also
achieve this with the switch. Both rise and fall can be manually set to create anything from a sawtooth
wave to triangle to a reverse sawtooth (or anything in between). By using the lower switch, a control
voltage can be set to affect RISE, FALL or BOTH slopes. Both sides feature (black) audio INs for lter-
ing effects etc.
The 4U pcb kit consists of a panel pcb serving as an interface to the front panel as well as a main pcb
which already contains most of the parts in surface-mount technology (SMT).

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RANDOMSOURCE.NET 2
Serge Slopes (DTG)
Please note:
• The main DSG pcb is the same as used for other incarnations of the DSG mk2 - whether the
DSG pcb is a “contemporary version” or a “classic” version does not matter. However, both
sides have to be set (adjusted) for common CV control:
• There must be a link or zero-ohm resistor at the 2 spots marked “COM”; and
• The 4 spots marked “SEP” have to be empty (remove any zero-ohm resistors).
• Connect only the pins within the white rectangular boxesmarkedonthepanelpcb.
Ignore the ones marked blue in the picture above.
• Use antistatic precautionwhenhandlingthepcb-don’ttouchthesmallSMDpartsandICs
withyourhands.
• Onlythesepartshavetobesolderedin:trimpots,pinstripestoconnectthemainpcbtothecom-
ponentpcb,MTApowerheader-thesecond(smaller)powerheaderisforconvenience,youcan
useittopoweranothermodulenexttotheDSG.
• LED:Toset/controlLEDbrightness,installeithertrimpots(“LED”)orresistors(e.g.2k)onthe
componentpcb-donotinstallboth!Use low current LEDs-atleast100-130mcdorultrabright
LEDs(60°)plusatrimpot of (only) 2k or (or a 2k resistor) for (fairly) bright LEDs (100-
150mcd).Ifyouuseultra-brightLEDs,a5korhighertrimmermightbeneeded.
• Thecomponentpcbcontainssomepotentiometerfootprintsthatallowyoutochosethedirection
inwhichthepotentiometerworks.Usethe“NORMAL”orientation(asmarkedonthepcb)unless
youhaveagoodreasonnotto.

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Serge Slopes (DTG)
Bill of Materials
Trimmers
2 100k DSG: Offset Trimpot (Bourns 3362P, Vishay T73YP104KT20 or similar)
DSG: to adjust the uni-polar output to a range of 0V to 5V
2 5k DSG: 1V/Oct Trimpot (Bourns 3362P, Vishay T73YP502KT20 or anything that
matches the footprint) to adjust the tracking of the 1V/Oct input.
Single turn is sufcient.
2 2K or more DSG: LED brightness
(instead of RLED resistors)
- on panel pcb -
Trimpot (Bourns 3362P or Vishay T73YP202KT20 or anything that
matches the footprint) to adjust the LED brightness. Pick value
depending on LED (see text).
Optional - use trimpot or LED resistors (not both!)
Resistors
(4) (2k*) RLED* Pick according to LEDs and desired brightness
only if not using trimmers for LED brightness!
Headers / pin connectors - DSG side
-SIL header 8pol OMIT - NOT NEEDED! (8-pin connector, links main pcb to component pcb)
4 SIL header 10pol 10-pin connector, links main pcb to component pcb
Misc
1 MTA-156 MTA-156 power connector
8 Banana Jacks
RED
DSG: TRIG IN, GATE OUT, Emerson-Johnson
Mouser: 530-108-0902-1 (red) or Thonk
2 Banana Jacks
BLACK
2x IN, Emerson-Johnson
Thonk / Mouser: 530-108-0903-1 (black)
5 Banana Jacks
WHITE
CV / unipolar Emerson-Johnson
Thonk / Mouser: 530-108-0901-1 (white)
2 LED 5mm low current pick color to suit LED lens
2 LED lens 5mm VCC, Mouser 593-3000R (red), 593-3000A (amber) ...
4 Potentionmeter
50k
SSG: linear (B50K) Alpha 9mm vertical pcb mount
available from Thonk, Tayda
6 Potentionmeter
50k or 100k
linear (B50K or B100K) Alpha 9mm vertical pcb mount
available from Thonk, Tayda
1 SPDT Switch SUB
(2 positions)
ON - ON
CYCLE
SUB-Miniature - Mountain-Switch
Mouser: 108-0042-EVX
2 SPDT Switch
(3 positions)
ON - OFF - ON
DSG: RISE / BOTH / FALL
SUB-Miniature - Mountain-Switch
Mouser: 108-0044-EVX
6 Davies knobs 1900H - Thonk

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RANDOMSOURCE.NET 4
Serge Slopes (DTG)
DSG mk2 Conguration
The DSG mk2 might be pre-congured to be used in a (full) DSG with separate control over Rise and Fall. This
is perfect for use in a 3” wide DSG, however, to use the pcb in a 2” version, you (may) have to change this
setting:
SEParate control of Rise / Fall: two 0R resistors (SEP) act as links / jumpers and COM is open.
COMmon CV control: no SEP resistors installed and COM is linked with a 0R resistor (or jumpered).
For Slopes (and all incarnations that have RISE / FALL / BOTH switches on both sides of the module)
both sides of the pcb have to be set to COMmon:
1. Remove the two 0R (zero ohm) resistorsatthetwospotsmarkedSEP(leftandrightof
COM)-youcanuseoneoftheminthenextstep.(ToremoveanSMTresistor,useafairlybigblob
ofsolderonthetipofyourirontoheatbothsidesoftheresistoratthesametimeandpushisout
quickly.)
2. Set a jumper at COMorsolderina0RresistorontothepadsunderneaththeCOMrectangle.
Building
This is simply a suggestion - you might nd a different workow more practical:
1. MounttheBananajacks,theLEDlensandtheswitchesontothefrontpanel.Ifyouuseretention
ringsfortheLEDlenses,attachtheringtothelens.(Do not mix up the switches!)
2. Screw(10mm)spacerstothepanelpcbifdesired-thisiseasiestdonewhilethepanelpcbisnot
yetattachedtothefrontpanel.
3. MainpcbandpanelpcbaretobeconnectedthroughprecisionDIPsocketandpins.Itisrecom-
mendedtousethepinsonthemainpcb(facingdown,solderedfromabove)andthepinsockets
onthepanelpcb(standingup,solderedfromthefrontpanelside).Breakorcutoffthepiecesyou
needandstickthemtogethersothatmainpcbandcomponentpcbformanicesandwich(don‘t
solderyet).Checkthatyoudidn‘tleaveoutanypins/holesandthatthesocketsareallonthe
sameside(panelpcb).Alsomakesurethepcbshavetherightorientation(sothatthepotswill
sitoutside!).Solderallthepinsinwhilekeepingthesandwichtogether-thisavoidsanymisalign-
ments.
4. Carefullyseparatethesandwich-ifyouusedprecisionsockets,thismaynottotooeasy-they
sticktogethernicely(givingagoodconnection).
5. SoldertheLEDtrimpotsorresistorsontothepanelpcb.Soldershortpiecesof(stiff)wire-about
10mmlong-intothepadsfortheswitches.Theseshouldstickupintheaironthesidefacingthe
mainpcbsandshouldonlygothroughthepcbasmuchasrequiredtosolderthemin(i.e.should
notstickoutmuchontheotherside).

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Serge Slopes (DTG)
6. Mountthepotsontothecomponentpcb.Potsshouldsitonthesidemarkedonthepcb-thisside
facesthefrontpanel.Don‘tsoldertheminyet.SticktheLEDsintothecomponentpcb-thelong
legmustbeatthe+side.
7. Carefullymountcomponentpcb(withthepotsandLEDsinserted)ontothefrontpanel.Firstslide
/pushtheLEDsintotheLEDlens-alltheway,thismaytakeabitofforce.Youmaythenhaveto
wiggleeachpotabittogetthepotsthrough.Makesurethethreadsofthepotsgothroughcom-
pletelyandthepotssitrightatthefrontpanel.Screwthepotstothepaneltomakesureofthat.
8. Onceeverythingisnicelyinplace,especiallytheLEDssittinginside(andnotontop)oftheLED
lenses,soldertheLEDsandthepotsontothecomponentpcb(whilethefrontpanelisattached).
9. Soldertheswitchesinbysolderingtheair-wiresontothecorrecpondingcontacts:
10. Solderthebananajacksin.Youcaneithersolderthemdirectlytothesurroundingvias(rings
around)or-whichmakesremovingeasiershouldyoueverneedtodothat-byinsertingastiff
(bare)wireintothelittlehole(via)andsolderthatwiretothetopofthebananajack:
11. Solderthethrough-holepartsontothemainboard.
12. Attachanyscrews/spacersifdesiredandmountthemainpcbontothecomponentpcb.
13. Connectapowercordsupplying+12V,GND,GND,-12VtotheMTA-headeronthemainboardand
youshouldbereadytogo:-)

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RANDOMSOURCE.NET 6
Serge Slopes (DTG)
DSG Calibration
LEFT SIDE: Use the CYCLE switch to get the left side (= top half of pcb) to cycle on its own - this way you can
directly start calibrating.
RIGHT SIDE: Patch GATE OUT into TRIG IN to start CYCLE mode (acting like an oscillator).
From the original kit instructions:
Turn the RISE and FALL knobs to center position or above. Patch the OUT(put) into an audio mixer or
Output Module to monitor the output. There should be a triangle wave present which can be changed to a
sawtooth wave of lower frequency by turning down either the RISE or FALL knob. The frequency and timbre
will depend upon the settings and the shape as set by the relationship between the Rise and Fall times.
Starting from a middle position, adjust the OFFSET trimmer so that the OUTput is in the range of 0V to 5V.
The module will most likely stop cycling towards either end of the trimmer - if this happens, move the trimmer a
bit back towards the center, unplug the patch cord between GATE OUT and TRIG IN and plug it in again - that
should bring the cycle back.
Adjust LED brightness according to taste - make sure you don’t turn the brightness up too much (i.e. trimmer
setting shoud be at least 1k unless you use white or blue LEDs).
Using the trimpots on the main pcb the 1V/Oct tracking can be adjusted. However, be aware that by design
the tracking of this module will not reach the range covered by dedicated oscillators. To adjust the tracking of
the RIGHT side, set the wave to an inverted Sawtooth (negative ramp, Rise is as steep as possible) and calibrate
for the lower range (up to 440Hz).
Power Consumption
DSG mk2: ≈85mA @ +12V and ≈65mA @ -12V
(Version 25. September 2017, 9:36 PM)
SERGE Modular by Random*Source. Module and circuit under license from Serge Tcherepnin. All rights reserved.