Leipzig TRUE analogue synthesizer User manual

analogue solutions Leipzig e&oe (c) 1-1-08 1
Leipzig

analogue solutions Leipzig e&oe (c) 1-1-08 2
Contents
SPECIFICATION...........................................................................5
INTRODUCTION...........................................................................7
APPLICATIONS............................................................................7
SAFETY INSTRUCTIONS ............................................................8
CIRCUITS IN DETAILS.................................................................9
VCO & 2........................................................................................9
NOISE GENERATOR..................................................................10
MIXER.........................................................................................11
VCF .............................................................................................12
Filtering External Sound Sources............................................12
ENVELOPE GENERATORS.......................................................13
EG1/2 ASR..................................................................................13
VCA.............................................................................................14
LFO .............................................................................................14
MODULATION ............................................................................15
MIDI to CV CONVERTER...........................................................16
To Set MIDI Receive Channel ...................................................16
REAR PANEL .............................................................................17
REAR PANEL DETAILS .............................................................18
REAR PANEL AUDIO CONNECTIONS .....................................19

analogue solutions Leipzig e&oe (c) 1-1-08 3

analogue solutions Leipzig e&oe (c) 1-1-08 4

analogue solutions Leipzig e&oe (c) 1-1-08 5
SPECIFICATION
Brief Overview:
Leipzig is a self contained TRUE analogue synthesiser. The voice circuitry is entirely
analogue, using all discrete and op-amp components. There is no voice DSP.
Leipzig has a similar sound and specification to the classic Moog Prodigy / Rogue
synthesisers, but with many improvements such as MIDI and more modulation paths.
VCO1
Tune, Glide, PW , PWM, Mod Source &Amount controls, Saw out, Pulse out
VCO2
Tune, Glide , Sync, PWM, Mod Source &Amount controls, Saw out, Pulse out
VCF
Low pass filter: Cut-off, Emphasis, Key Track, ENV1 Mod, Mod Source & Amount
controls
Mixer
Audio source mixer, including external audio inputs
VCA
Mode switch, Output volume
ENV1
ASR envelope with trigger LED
ENV2
ASR envelope with trigger LED
LFO
Square & Triangle waves
Noise Generator
White noise
SUB oscillators
-1 from VCO1
-2 from VCO2
MIDI to CV Converter
16 bit high resolution with auxiliary controller CV2 output (modulation CV)
Many modulation possibilities.
Rotary controls:
25
Rotary switches:
6

analogue solutions Leipzig e&oe (c) 1-1-08 6
Push button:
1
LEDs:
6
Jack sockets (6.35mm, mono);
3
MIDI Sockets;
2
Rugged steel contruction
Dimensions:
Height: x 5U
Weight:
xKg
Power:
x
Accessories:
Manual
Mains adaptor (230v)

analogue solutions Leipzig e&oe (c) 1-1-08 7
INTRODUCTION
Congratulations on buying the Leipzig synthesiser. Leipzig is part of the Analogue
Solutions range of analogue music equipment. Leipzig is a precision electronic musical
instrument. It combines all the often needed music electronic circuitry to make a music
synthesiser in one compact module.
No compromise has been made with the construction of Leipzig. Cheaper options in
parts have not been used;
Full rugged steel case - no plastic mouldings
Good quality smooth potentiometers, fully sealed against dust
Good quality knobs with spun aluminium caps
High grade double sided lead free circuit board
All power and signal input/outputs have EM filters to remove external noise and im-
prove immunity
High Quality DAC for MIDI to CV conversion - 16bit!
Very stable MIDI to CV conversion
Very stable analogue oscillators
Expensive blue LEDs
Hand built by humans
Lasting quality and appeal with a life far longer than any software plug-in or DSP
synth
APPLICATIONS
MONOSYNTHESISER
Leipzig is for use any time you need analogue sound effects, fat basses, screaming
leads, beeps, tones, zaps, and all the other crazy sounds associated with analogue syn-
thesis. Use in place of your boring digital synths and DSP soft synths.
EFFECTS PROCESSOR
Leipzig has an audio input socket, so you can feed external sounds into the onboard
analogue filters for analogue processing.

analogue solutions Leipzig e&oe (c) 1-1-08 8
SAFETY INSTRUCTIONS
Please read carefully before using:
• Only use the correct power adaptor - 230V (or 115V whatever your country
needs)
• Never handle the adaptor with wet hands
• Never excessivly bend the adaptor cable or get it trapped or place heavy objects
on it. If the adaptor cable becomes damaged, replace the adaptor.
• Ensure the unit is disconnected from the mains before moving or cleaning.
• Always disconnect the unit from the mains if there is lightning in your area.
• Ensure the unit is on a stable surface, and never place heavy objects on top of it.
• Never allow young children or animals to operate the unit or adaptor.
• Do not use excessive force when using the controls or inserting cables to the con-
nectors.
• Theunitshould notbeoperated intherain ornearwater andshouldnot beexposed
to moisture. If the unit is brought from a cold environment to a warm one, the unit should
be left to reach the ambient temperature.
• Keep unit away from heat sources, such as radiators, ovens, heaters etc.
• Never allow the unit to get wet. Do not operate it near water, like pools, sinks, bath-
rooms etc. Do not place beverages on or near it.
• Never open the case or attempt to make repairs. Refer any servicing to a qualified
service personnel.
Preventing damage to other connected devices;
Leipzig has a very high dynamic range. It is capable of produce loud signals of very
high and sub-sonic frequencies that could blow inadequate speakers if played too loud. It
is recommended that input levels to external equipement (mixers, amp's etc.) is kept low
when first connected, and then sowly increased to a userable level.
Maintenance Instructions
Any cleaning of the the case should be done with a clean lint-free cloth. DO NOT
USE SOLVENTS OR CLEANERS, as this will deteriorate the exterior appearance of the
equipment.
Mounting
Mounting does not mean 'place on the wall' or 'to make love to' in this instance. Place
the unit soundly on any stable surface so he cannot fall off or over, causing it or yourself
injury.

analogue solutions Leipzig e&oe (c) 1-1-08 9
CIRCUITS IN DETAILS
Here follows details on all the sockets and controls, with brief simplified explanations
of what the circuits do. We have not gone into technical details on how and exactly what
each circuit does but tried to explain each control's function and effect.
Anyone who has used synthesisers before should be familiar with the terms used and
therefore be able to predict their behaviour and how they affect the sound. The best way
to learn how to use Leipzig is to go straight ahead and play with it. Reading of this manual
may only be neccessary for finer operational detail.
VCO & 2
The voltage controlled oscillators (VCOs 1 and 2) produce
the raw audio waveform usually used as the initial source for
sound creation. They provide cyclic audio waveforms that can
bepitched.VCOs usuallyreceivetreatment fromtheVCF to turn
their basic tones into pleasant sounds.
TUNE
Two independent TUNE controls for the oscillators. Controls the
course pitch of the VCO. Range is about +/- 2 octaves.
GLIDE
Two independentGLIDEcontrols (portamento) forthe oscil-
lators.Eachtime you play anewnote, the pitchwillglidefrom the
last note to the new note. The GLIDE control alters the speed.
At minimum there is no glide.
Pulse Width
(Just below VCO1 GLIDE control). For VCO1 only. This alters the pulse width for
VCO1's square wave (alters the 'duty cycle'). If you do not understand this, don't worry
about it! Just turn it and hear how the tone changes.
SYNC
VCO2 only. This switch routes a sync signal to VCO2. Oscillator sync is where a
master signal (selected by the switch) will reset the waveform of a slave signal (VCO2 in
this case) each time the master waveform starts a new cycle.
Try the different settings and listen to the effect. You may have to modulate the pitch
of either VCO1 or VCO2 to enhance the effect.There is a balancing act between the pitch

analogue solutions Leipzig e&oe (c) 1-1-08 10
of the two sound sources (usually the 2 VCOs) to get a good effect.
Sync source choices are;
VCO1 square wave
LFO square wave
EXTernal signal
Off (flat line symbol)
PWM
Two independent pulse width modulation controls (PWM), one for each VCO. This
allows modulation of the square wave 'duty cycle'. Once again, don't worry about this
technically, just enjoy the effect!.
Turn to the left for LFO triangle wave modulation.
Turn to the right for Envelope 2 modulation.
Centre is zero (no modulation).
For VCO1, it is best to first put the Pulse Width control to the centre before using
PWM, otherwise the sound might cut (unless that is the effect you want!)
NOISE GENERATOR
Thenoisegenerator produces whitenoise.Thisis like thehissyou hear betweenradio
stations. The signal is available for filtering via the EXT/NOISE mixer control.
Noise would be used for sound effects such as breath, wind, percussion, etc.

analogue solutions Leipzig e&oe (c) 1-1-08 11
MIXER
The mixer is used to bring various audio source signals together
for filtering. There are four mixer controls. In all cases, centre is
zero volume, or turn to the left or right to select either of two sound
sources.
NOISE/EXT1 level
Turning the control anti-clockwise in increasing amounts sends
the signal (if any) coming in off the rear panel EXT1 socket to the
mixer.
Turningthe controlclockwise in increasingamounts sends white
Noise to the mixer.
In a central position no signal is sent to the mixer.
-1/-2 SUB level
SUB is a duplication of the VCO square wave output, but at a
lower octave. Use to beef up the sound.
Turning the control clockwise in increasing amounts sends a -2
octave VCO2 square wave signal to the mixer.
Turning the control anti-clockwise in increasing amounts sends
a -1 octave VCO2 square wave signal to the mixer.
In a central position no signal is sent to the mixer.
Saw/Pulse VCO1 level
Turning the control clockwise in increasing amounts sends VCO1s
pulse signal to the mixer.
Turning the control anti-clockwise in increasing amounts sends
VCO1s sawtooth wave signal to the mixer.
In a central position no signal is sent to the mixer.
Saw/Pulse VCO2 level
Turning the control clockwise in increasing amounts sends VCO2s
pulse wave signal to the mixer.
Turning the control anti-clockwise in increasing amounts sends
VCO2s sawtooth wave signal to the mixer.
In a central position no signal is sent to the mixer.

analogue solutions Leipzig e&oe (c) 1-1-08 12
LED indicators
Each oscillator has it's own 'frequency' LED. This is taken from the VCO's pitch, but
of course divided down enough octaves so you can see it flash!
VCF
The voltage controlled filter low pass filter (VC LPF) is used to
alterthetone of the signal coming from the mixer output (VCOs/Noise
) and is the heart of what gives an analogue synth its character.
CUT OFF
This sets the cut-off frequency, the point at which the LPF will
start to filter-out harmonics.
EMPHASIS
Emphasis (Resonance, Q or Feedback) is a feature of adding
feedback to the filter circuit. The output of the filter is fed back into
thefilter input.Emphasis sets the level of feedback.As the control is
increased to higher levels the filter will self-oscillate. The oscillation
frequency is set by the cut-off control.
UseEmphasis to alter the tone of thefilter effect.It can be used
to create 'squiggy' sounds and 'pulse hits'.
KEY TRACK
ThepitchCV (CV1) alsocontrolsthe filter-cut off.The KEYTRA-
CL control alters how much this happens. Key Track is sometimes
also known as Key Follow. This is used when you want a brighter
sound as you play a higher pitch, since an increasing pitch means
higherCV1, which in turn increasesthe cut-offfrequency (assuming
theKEYTRACK control is up).This brighteningof sound is how real
sound behaves. 'Real' instruments usually sound brighter in their
higher registers.
KEY TRACK can also be used to 'play' the resonance, but set-
ting EMPHASIS to self-oscillate.
ENV1 MOD
This control alters how much the cut-off is modulated by enve-
lope generator 1. Balance this control with the CUT OFF control.
Filtering External Sound Sources
External sound sources, such as vocals, guitars, mixer sends, samplers, etc. can be
sent through the filter for extra treatment. Note, mic's and guitars may need pre-amp'ing;
use if the signal is too quiet.
Simply plug the sound source into the rear panel EXT1 socket.
Turn the mixer control EXT/NOISE to EXT, and up to a suitable level.
You may wish to return the VCO1 and VCO2 mixer controls to their centre positions
so the VCOs cannot be heard.

analogue solutions Leipzig e&oe (c) 1-1-08 13
Turn the VCAmode switch to THRU (ON).This will leave the VCAopen so a constant
signal can be heard.
Finally, play around with the filter and modulation settings as neccessary.
The VCO signals can also be introduced, and use the various VCAmodes and enve-
lopes if you wish to contour the sound level and add additional effects.
ENVELOPE GENERATORS
LED indicators
These will turn on each time the EGs are
triggered.
EG1/2 ASR
EG1andEG2 are identical.They areASR
(attack / sustain / release) envelope genera-
tors. Use to modulate various parameters of
the synthesiser.
ATTACK
Controls the Attack time. This is the rate
at which the envelope signal will take to reach
full level when the MIDI note/key pressed.
DECAY / REL
Controls the Decay or the Release time
- the time it take the envelope signal to return
to zero when the key is released.
SUSTAIN
If this switch is on, then the DECAY / REL
controlbecomes Release. If akeyishelddown,
the EG is sustained at full level.
If this switch is off, then the DECAY /
REL control becomes Decay. There will be no
sustain.
Note: this switch has 4 positions. The left
2 positions turn SUSTAIN off, and the right 2
on. We are unable to get 2 way switches for
the series of potentiometers/switches that we
use.

analogue solutions Leipzig e&oe (c) 1-1-08 14
VCA
TheVoltageControlledAmplifier (VCA) isthe circuit thatis used
to change the output volume. Normally an envelope signal would be
used to do this, so the sound starts loud then gradually fades away.
The filter audio output is hard-wired to the VCA signal input.
Mode rotary switch control
The VCA can be controlled in 4 modes;
EG1
When EG1 is selected, the envelope signal of EG1 is used to
modulatethe VCAlevel. Use itif you requirethe VCAlevel tochange
over time.
EG2
When EG2 is selected, the envelope signal of EG2 is used to
modulate the VCA level. Use it if you require the VCA level to change over time.
GATE
When GATE is selected, the MIDI converter's Gate signal is used to modulate the
VCA. With this, the VCA level is either off or full on. The audio envelope would be like an
organ's, with no attack or decay time.
THRU
When THRU (on or bypass) is selected, the VCA is left permanently on at full level.
Use this setting if you wish to use the Filter as an effects processor, to process external
audio fed into Semblance.
VOLUME
This sets the output volume of synth, i.e. the output level from the VCAthat is output
from the SIGNAL output socket.
LFO
This is in the MODULATION panel (see later). The Low Frequency Oscillator (LFO)
is basically identical to a VCO; it is another oscillator, except that it produces periodic
wave forms of low frequency, typically sub-audio. These slow cyclic waveforms are used
for modulating other circuit parameters, for example, for sweeping the filter cut-off up and
down, either slowly for a nice sweep, or faster for a 'wah-wah' type effect. It could be used
to modulate the VCO pitch for vibrato.
The LFO is found in the MODULATION panel (see diagram).
LFO RATE
This sets the frequency (speed) of the LFO.
LFO SPEED LED indicator
This wil turn on each time the LFO signal is at a positive voltage, indicating the speed
of the LFO waveform.

analogue solutions Leipzig e&oe (c) 1-1-08 15
MODULATION
The modulation panel is where you route
SOURCE modulation signals to their DESTI-
NATIONS. Think of it as a modulation matrix.
There are three modulation destinations
in this panel;
VCO1 (pitch)
VCO2 (pitch)
FILTER (cut-off)
These can be modulated by the sig-
nals selected by their respective SOURCE
switched.TheAMOUNTcontrol alters thelevel
of modulation.
The modulation sources available are;
VCO1: LFO triangle, LFO Square, EG1,
VCO2 square
VCO2: LFO triangle, LFO Square, EG2,
MIDI (modulation CV / CV2)
FILTER:LFOtriangle,LFOSquare,VCO2
square, MIDI (modulation CV / CV2)
These are not the only modulation types
available. Other modulations are available
within each feature's own panel (e.g. VCO1
and 2 can have PWM, the LPF has EG1 and
KEY TRACK modulation).

analogue solutions Leipzig e&oe (c) 1-1-08 16
MIDI to CV CONVERTER
TheMIDI to CV converter (MCV)is adevice that convertssome
MIDI signals into analogue voltages. It allows analogue synthesiser
circuits to be integrated and used with your MIDI set-up.
MIDI messages responded to are Note on/off, Velocity, Mod
Wheel, All notes off. Note messages provide analogue outputs for
pitch CV, auxiliary CVand Gate.
Activity LED
The Activity LED will briefly light whenever it receives a MIDI
message that itself will respond to, i.e. a message on the correct
channel, and of correct type, note on/off and mod wheel (if CC/VEL
source is set to mod wheel). It remains on when Red Square is in
Program mode.
The MIDI to CV converter produces three kinds of signal;
CV1 This is a pitch CV and is hard wired to control both VCO pitches.
CV2 This is a modulation CV that is wired into the modulation panel
Gate This is a note on/off signal wired into the VCAand EG triggers.
To Set MIDI Receive Channel
Press and hold the Program button. Then do either;
Press a MIDI key. This will set and store the receive channel to the channel received
in the note data.
CV2 will set itself to Velocity.
Release the Program button.
Or
Move a Continuous Controller. This will set and store the receive channel to the chan-
nel received in the CC data.
CV2 will set itself to the CC number received.
Release the Program button.
Note; The Program button must be held in whilst pressing a key or moving a control-
ler. CC number 7Fh is reserved. Avoid using this controller.

analogue solutions Leipzig e&oe (c) 1-1-08 17
REAR PANEL

analogue solutions Leipzig e&oe (c) 1-1-08 18
REAR PANEL DETAILS
The rear panel is shown above and detailed below;
POWER IN
This unit features a standard IEC power socket. Check the correct mains voltage is
selected on the switch on the bottom panel - 115V or 230V AC. Disconnect the unit from
the mains supply before switching to the correct voltage for your mains supply.
MIDI IN
Plug your MIDI cable in here. Connect this to the MIDI out or thru of your MIDI con-
troller.
MIDI THRU
The MIDI data coming into the In socket is copied to the Thru socket. This is so you
can control additional devices from your MIDI controller without the need of a MIDI thru
box. The Thru socket will not function when in Poly mode.
EXT1 signal input socket
This is the input socket to feed audio signals into the synth. The signal is routed to
the EXT audio input of the mixer.
EXT2 signal input socket
This a second input socket to feed audio signals into the synth. The signal is routed
to the EXT audio input of the mixer.
SIGNAL output socket
Thisis the main audio outputLeipzig Itis the signal output fromthe VCA,post-Volume
control.
All jack sockets are 6.35mm mono.
Try to keep your leads under 3M to keep the signal quality as clean as possible.

analogue solutions Leipzig e&oe (c) 1-1-08 19
REAR PANEL AUDIO CONNECTIONS
The main signal output is on the rear panel. Connect this socket to a spare mixing
desk input channel. If you want to feed external signals into Leipzig, use the rear panel
EXT1 socket. Maybe hardwire if from your desk's effect send.
It is recommended to keep your MIDI and CV/audio cables as short as possible to
keep the signal quality as high as possible. We recommend no more than 3 metre cable
lengths.
SOUND SOURCE
Synth, sampler,
guitar, etc. AUDIO
OUT
To main mixer, hard
disc recorder, etc.
AUDIO
OUT
AUDIO IN

analogue solutions Leipzig e&oe (c) 1-1-08 20
Specification subject to change without notice.
Warranty
This unit comes with a 1 year (from purchase date) back to base warranty, (i.e. cus-
tomer must arrange and pay for carriage to and from Analogue Solutions or the dealer
from which purchased).
Thiswarrantyshall not applywherethe product hasbeensubject to alteration,misuse,
accident, neglect (such as extremes of temperature and/or moistur) or to wear resulting
from normal use.
We will normally carry out most the labour or repairs free of charge for an extended
period of an additional 4 years from purchase date, but this may not included cost of any
damaged parts which will be charged for.
Atthe sole discretion ofAnalogue Solutions,the warrantyis deemed to be voidshould
the unit be or considered to have been opened or any other modifications or tampering be
carried out by unauthorised parties.
CE Compliance
This unit complies with Complies with EU Directives 73/23/EEC and
89/336/EEC. Standards: EN55103-1, EN55103-2, EN60065