20cc Spectron: Classic Tape Dual Oscillator | Knobcon 2026

video upload by CatSynth TV

"Andrew from 20CC takes us on a tour of the TXX-1 Spectron, a dual-voice module based on samples from classic recording-based instruments like the Mellotron and Optigan.

To find out more, please visit https://www.20cc.cool/

'The 20CC TXX-1 Spectron is a Eurorack format dual oscillator inspired by vintage analog multisampling instruments such as the Mellotron, Chamberlin, and Optigan. Spectron uses a unique combination of synthesis and sampling techniques to bring the rich, warbly sounds of these classic instruments into Eurorack for the first time, while also offering new possibilities to manipulate, warp, and mangle them.'" Patreon: / catsynth | https://shop.catsynth.com | https://ko-fi.com/catsynth


0:00 Introduction
0:15 Spectron
1:49 Availability
2:08 How sounds are added to Spectron

"The 20CC TXX-1 Spectron is a Eurorack format dual oscillator inspired by vintage analog multisampling instruments such as the Mellotron, Chamberlin, and Optigan. Spectron uses a unique combination of synthesis and sampling techniques to bring the rich, warbly sounds of these classic instruments into Eurorack for the first time, while also offering new possibilities to manipulate, warp, and mangle them.

Analog multisampled instruments had their hey-day in the 1950's through the 1970's. They used analog recording technology - tape recording in the case of the Mellotron and Chamberlin, and optical sound printing on analog photographic film in the case of the Optigan. Each key corresponded to a recording of a note played on another instrument, often orchestral sounds like strings, woodwinds or choirs, which would play back when the key was pressed. All of Spectron’s sounds are based around full, per-key recordings of vintage multisampled instruments.

Rather than simply triggering discrete samples, Spectron organizes many samples to create the illusion of a continuous voltage-controlled oscillator. As pitch changes, playback seamlessly transitions between recordings, preserving the character of each original tape while allowing smooth, continuous frequency control.

There are two assignable timbre shaping sections not normally found on sample-based instruments: FM and Sync. These are tuned to range from subtle modulations that recontextualize familiar sounds, through radical transformations that are barely recognizable, and all the way to harsh and clangorous, with continuous CV control of all points between."


FEATURES:

More than 20 "tapes" recorded from vintage instruments, with more planned after release.

Dual oscillator design: Voices A and B can operate independently or in tandem.

Each voice has a volt-per-octave CV input to control pitch, as well as a gate/trigger input to trigger the samples' attack portion as well as the built-in envelope. The inputs of Voice A are normalled to the inputs of Voice B when nothing is plugged in to the latter.

2 CV-addressable timbre-shaping controls, each with dedicated attenuvertor:

FM - Modulate A's phase at B's pitch, or vice-versa, or cross-modulate. Bell-like percussion, sub-octave overblown tones or harsh static are all there.

SYNC - Samples are played back at progressively higher rates, while the playback head is continuously reset to every cycle boundary. The result soometimes sounds like a deep flanger, or can even resemble time-stretching and pitch shifting techniques.

Timbre controls and CV inputs can be assigned to A, to B, or to both.

An optional built-in ASR envelope can control the amplitude, turning Spectron into two complete synthesizer voices without the need for other modules.

Timbre control CV inputs can be normalled to the either the envelope or the built-in LFO, which has selectable basic waveshapes.

A four-voice pseudo-polyphonic mode allows longer releases to overlap with new notes, enabling a form of multi-voice harmony.

The modulation matrix with multiple sources including two dedicated CV inputs, can route to numerous destinations not otherwise available, enabling advanced patching techniques.

There are two ways to externally control tape selection, which enable multi-timbral sequencing and voice hocketing techniques:

The Scan CV inputs offer direct CV control over tape selection.

Enabling Tape Trigger will cause the tape to change on every recieved trigger. This can also be combined with the Scan functionality.