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Reading Guide · Patch Diagrams

How To Read Patch Diagrams

Patch diagrams are signal maps. They show how audio and control signals travel between instruments: from a source, through processing, to an output. Each symbol represents either a piece of equipment, a type of connection, or an annotation about how to operate it. This guide is organised by symbol category so you can look up any figure you encounter on a diagram.

Found a patch you want to try? Browse the full archive at the Patch Archive or identify equipment on the Studio 1 Overview.
Left column
Shows the actual symbol as it appears in the patch diagram, the exact figure you'll see drawn on a patch sheet.
Middle column
A photograph of the real instrument or connector the symbol represents, so you can spot it in the studio.
Right column
The name, an explanation of what the device does in a patch, and a practical tip for using it.
01
Where sound begins

Signal Sources

Oscillators, noise generators, and other devices that originate an audio or control signal in the patch.

Sine wave symbol
Sine wave symbol
oscillator
e.g. Rohde & Schwarz oscillator
Sine WaveSource
A sine wave can be produced by a sine wave oscillator, but also by function generators, as you will see below. A sine wave is a pure, smooth cyclical waveform with no harmonic content beyond the fundamental frequency. In Studio 1 this is most often generated by the Rohde & Schwarz oscillators or the HP function generators.
→ In studio 1 the oscillators can be found as numbers 1 to 12.
Pulse wave symbol
Pulse wave symbol
function-generator
e.g. HP function generator
Pulse Wave Source
A waveform that switches abruptly between two voltage levels. When the on/off time is equal it is a square wave; when the duty cycle varies it is a pulse. Rich in odd harmonics, it produces a hollow, buzzy tone. Widely used as a clock signal to trigger other modules in a rhythmic sequence.
→ In studio 1 the pulse wave generators (function generators) can be found as numbers 30 to 36 and 55 to 57.
Function Generator symbol
Function Generator symbol
function-generator2
e.g. HP 3300A Function Generator
Function GeneratorSource
A function generator can output a various waveforms depending on the exact model. At times it will be referred to by using a sine or pulse symbol. When the FG symbol is used it means the exact waveform is not crucial to the patch and may vary. In Studio 1, 4 different types of function generator can be found, 10 units in total.
→ In studio 1 the function generators can be found as numbers 30 to 36 and 55 to 57.
Noise symbol
Noise (generator) symbol
noise-generator
e.g. Noise Generator unit
NoiseSource
A noise output is a random voltage signal containing energy across a broad frequency range. White noise distributes energy equally per hertz; pink noise distributes it equally per octave. In many Studio 1 patches noise is the primary sound source, shaped by filters into tonal or textural results.
→ In studio 1 the noise generators can be found as numbers 13 and 49 to 51.
Function Generator symbol
Pulse Generator symbol
pulse-generator
Pulse generator unit
Pulse Generator Source
A pulse generator is designed to generate pulses with adjustable timing parameters. It provides independent control over pulse width, repetition rate, amplitude, and delay, enabling accurate configuration of signals. The unit supports both internal triggering and external trigger inputs, allowing synchronization with other instruments.
→ In studio 1 the pulse generators can be found as numbers 52 to 54.
Function Generator symbol
Word generator symbol
word-generator
HP word generator unit
Word Generator Source
A word generator outputs a programmable binary sequence as voltage pulses. It is often used as a sort of step sequencer: each "word" is a short repeating pattern of on/off pulses. By using the same clock input on multiple word generators intricate rhythms and beats can be composed.
→ In studio 1 the word generators can be found as numbers 41 to 43.
02
Shaping & moving the signal

Processing, Filtering & Modulation

Devices that modify frequency content, amplitude, or waveform, plus control voltage generators that change parameters over time.

Bandpass Filter symbol
BPF / selective amp
selective-amplifier
Selective Amplifier unit
Selective Amplifier Filter
A narrow bandpass filter that passes only a selected range of frequencies while attenuating everything else. The "Q" knob controls bandwidth: a high Q gives a narrow, resonant peak, and a low Q gives a broader, gentler contour. The selective amplifier is always referred to as BPF in patch diagrams. When recreating a patch any BPF can be used, if not specified otherwise.
→ In studio 1 the selective amplifiers can be found as numbers 63 to 65.
Bandpass Filter symbol
Bandpass Filter
bpf
Bandpass Filter unit
Bandpass FilterFilter
A bandpass filter can be tuned to isolate a specific range of frequencies around a chosen center frequency.
→ In studio 1 the bandpass filters can be found as numbers 15 and 16.
Bandpass Filter symbol
Passive Bandpass Filter
pbpf
Passive Bandpass Filter unit
Passive Bandpass FilterFilter
The passive bandpass filter divides audio into octave-wide frequency bands. Each bandpass section allows frequencies within a specific range to pass through while attenuating frequencies outside that range.
→ In studio 1 the passive bandpass filters can be found as number 14.
Third Octave Filter symbol
Third Octave filter bank
Filterset
E.G. HP 8085A Filter Set Unit
Third Octave FilterFilter
A bank of bandpass filters spaced one third of an octave apart across the full audible spectrum. On the HP 8058A unit, each band has an individual output, allowing a single input signal to be split into separate frequency components. In some patches, individual bands are often fed back into each other to create complex resonant structures. In studio 1 there are two 1/3 octave filters.
→ In studio 1 the third octave filters can be found as numbers 25 and 26.
Boxcar Integrator symbol
Boxcar integrator symbol
Boxcar-Integrator
Boxcar Integrator unit
Boxcar Integrator Processing
The boxcar integrator is a gated signal processor that averages input signals over defined time windows, effectively isolating specific portions of a waveform. It can produce smoothed or pulsed audio outputs, emphasizing rhythmic elements or creating unique textures from otherwise noisy or transient signals.
→ In studio 1 the boxcar integrators can be found as numbers 69 and 72.
Lock-in Amplifier symbol
Lock-in Amplifier
Lock-in-Amplifier
Lock-in Amplifier unit
Lock-in AmplifierProcessing
The lock-in amplifier/phase detector extracts small AC signals from noisy environments using phase-sensitive detection. It can transform input signals into unusual audio outputs, often producing strange tones, rhythmic pulses, and unpredictable distortion. This also makes it useful for experimental sound design and creating textures.
→ In studio 1 the lock-in amplifiier can be found as number 71.
Ring Modulator symbol
Ring Modulator
Ring Modulator
Ring Modulator unit
Ring ModulatorProcessing
The ring modulator allows an input signal to be multiplied by a second signal, in this case a sine wave. This process generates overtones, which can give the sound a metallic character. The multiplier is also often used as a ring modulator. When RM is specified, a patch uses the ring modulator connected to the main mixer.
Multiplier symbol
Multiplier
Multiplier
EG&G PARC multiplier
MultiplierProcessing
The multiplier is a signal processor that performs real-time multiplication or division of input signals. It can be used to combine or modulate signals, enabling applications such as amplitude modulation, frequency scaling, or complex signal synthesis. It is mostly used in its multiplication mode, where two signals are multiplied (ringmodulation).
→ In studio 1 the multipliers can be found as numbers 66 and 67.
Spring Reverb symbol
Spring Reverb
Main Mixer
Mixer (Aux Channels)
Spring ReverbProcessing
The spring reverb in studio 1 is patched to the main mixer and can be used by sending a signal through aux channels 5 and 6 to the reverb. The spring reverb is a physical unit that can be used to simulate space, but also for resonant sound-shaping within feedback patches.
Wave analyser symbol
Wave Analyser
Wave Analyser
Wave Analyser
Wave AnalyserModulation
The wave analyser can function as a standalone narrowband measurement system, isolating and measuring specific frequency components with high precision. Combined with the sweeping local oscillator unit, it allows both static spectral analysis and dynamic frequency filtering, making it useful for extracting, emphasizing, or reconstructing complex audio signals.
→ In studio 1 three wave analysers can be found as numbers 58, 59 & 60.
universal programmer symbol
Universal programmer
Universal Programmer
EG&G Universal Programmer
Universal Programmer Control Voltage
The EG&G model 175 is a signal generator and timing controller for automated testing. It produces voltage pulse sequences with programmable timing and amplitude, allowing it to control or trigger other modules.
→ In studio 1 the universal programmer can be found as number 62.
03
How signals travel & notes on the diagram

Connections, Routing & Annotations

Cable types, routing marks, knob positions, output labels, and other notations written onto diagrams.

control voltage symbol
Control Voltage
Control Unit
16 Channel VCA Unit
Control Voltage (CV) Connection
Any signal used to change a parameter rather than be heard directly. CV lines can, for example, connect an LFO, envelope, or programmer output to the frequency, gain, or filter cutoff input of another module.
→ In studio 1 the units that allow for control voltage can be found as numbers 37, 38 and 44.
Gate Input symbol
Gate Input
Control Unit
Function Generator Control Unit
Gate InputConnection
A gate input receives a control signal used to trigger or activate a function rather than be heard directly. Gate signals can, for example, trigger an envelope, start a sequencer step, or switch another module on and off.
→ In studio 1 the units that allow for gate inputs can be found as numbers 37 and 38.
Gate Input symbol
Trigger Input
Control Unit
Function Generator Control Unit
Trigger InputConnection
A trigger input receives a short control signal used to initiate an event rather than be heard directly. Trigger signals can, for example, start an envelope, fire a single drum sound, or advance a sequencer step.
→ In studio 1 the units that allow for gate inputs can be found as numbers 37 and 38.
Split Signal symbol
Multiple / Split Signal
Control Unit
Function Generator Control Unit
Multiple / Split SignalRouting
A filled dot on a line indicates that one signal is being sent to two or more destinations simultaneously. For example, a single oscillator can simultaneously provide audio to a filter and a control voltage to a ring modulator. The FG control unit and custom 16-channel VCA both include multiples, where one input can be split into multiple outputs. In Studio 1, there are also BNC cable splitters that can be attached anywhere.
→ In studio 1 the multiples can be found as numbers 38 and 44.
Mix symbol
Mix / Output
Main Mixer
Mixer / Output
Mixer / OutputMonitoring
The mixer icon marks where the final audio signal leaves the patch and goes to speakers or a recording device. Some patches have multiple mixer points labelled, which means that the audio goes through a submixer before going to the the final mixer.
Quick reference

An example of a typical patch, step by step

SOURCE Oscillator / Noise / Audio PROCESSING Filter MODULATION LFO / Cv / Trigger ROUTING Mixer SECONDARY Further processing feedback loop OUTPUT Speakers / Record

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