Atlantis

Description

Dual Oscillator Subtractive Synth Voice

The Atlantis is heavily inspired by the architecture and sound of the classic Roland SH-101. It has always been one of our  favorite synths and we really liked how the seemingly limited architecture allowed for all sorts of creative and musically useful sounds to be easily generated.

Just like the 101 it is quick to dial in beautifully rich bass and lead sounds. However this module uses triangle core VCOs (based on the Dixie core) instead of Saw core which respond much more musically to FM. The modulation oscillator can be used as an LFO or VCO (audio rate) and both track very precisely over 8 or more octaves.

In the mixer section you can adjust the balance of the primary oscillators waveforms including a sinewave which is normalled to the EXT IN jack. You could also patch in one of the modulation oscillators waveforms into this channel and be able to operate the Atlantis as a proper two oscillator synth. There is a switch labelled “LINK” which enables the modulation vco pitch to be based as an offset of the primary VCO. This is useful when using it as a stacked dual vco or when you have the mod VCO acting as the linear FM source for the primary vco and wish to maintain the ratio.

The filter section is a Roland style cascaded 4 pole multimode filter with LP, BP and HP modes. The LP Boost switch engages a special mode useful for the LP that produces a much fatter and prominent sound that is not drowned out by resonance (unlike the original SH-101). The filter self-oscillates to produce a very clean sine wave which also tracks 1V/Oct. Between the Mod VCO, Primary VCO, Sub Oscillator and resonating filter it is possible to layer up to four different pitches at one time.

The envelope section is an ADSR with a dual range switch. It also can be set to a looping mode which can be gated on/off externally.
The output VCA feeds into a two level output clipping circuit that you can use to get a much ballsier/dirtier sound.

Main features:

• Modulation VCO: triangle core with Hard Sync and Link switch to connect pitch to primary
• Primary VCO: triangle core with Hard Sync, Octave switches, Linear/Exp FM and PWM
• Global modulation bus with four VCO waveforms, noise and S&H options
• Cascaded 4-Pole multimode filter
• Looping ADSR with range switch, manual gate, and external level (velocity) control.
• Three position output clipping circuit
• 27 jacks for creative and complex patching options
• Header on back of pcb that allows it to be linked (normalled) to the Intellijel Metropolis sequencer
• Skiff Friendly

Summary of enhancements/differences over the SH-101 core:

• Discrete triangle core vcos (with far better tracking and Hard sync)  instead of CEM based IC.
• Primary vco has linear FM (not just exp)
• MOD VCO can be linked to the primary VCO pitch CV.
• Modulation oscillator switchable from LFO to VCO
• Filter is multimode, 2/4pole switchable and has a special LP boost mode
• Filter allows for selection of inverted ADSR mod source
• Mixer section includes and external source which is normalled to a sinewave
• Filter has built in soft clipping
• Envelope has looping option, re-trigger and selectable time range
• Output VCA has two stage clipping circuit
• Patch points for every synthesis section

Spec

• Width: 40HP
• Max depth: 38mm
• Power: 214mA @ +12V, 196mA @ -12V