Abstrakt Instruments announces VS-1 Polyphonic Analog Synthesizer 1:1 Oberheim™ OB-X in Rack
The VS-1 combines vintage analog sound with modern features, designed for those that find modern synths over-perfected. Based on the discrete analog design of the iconic Oberheim™ OB-X, the VS-1 utilizes many of the same design trade-offs, including a signal path comprised of discrete transistors, op-amps, & 3080 OTA’s utilizing through-hole components. Combined with modern digital control, a clean & simple interface, and packed into a 3U rack… this is the essence of the VS-1.
It’s all about the tone. Based on the classic OB-X, each voice consists of two analog VCO’s and a 12dB OTA Filter (LP/BP/HP) and VCA.
VCO’s Two discrete VCO’s per voice with saw and pulse waves. Pulse width can be adjusted from 0% to 100%. VCO1 can be modulated by VCO2 (crossmod) and VCO2 can by hard-synced to the frequency of VCO1. VCO’s can also be modulated by two analog LFO’s, two digital LFO’s per-voice, and a DADSR 5-stage envelope generator.
Noise Analog white & pink noise.
Portamento Analog polyphonic portamento gives a natural clustering effect between voices as the analog components are never perfectly matched. Although this requires many additional components it has been included – another example of small imperfections that impart character. In addition, digital portamento with both fixed rate and fixed time modes is also included. 12dB OTA Filter The classic resonant 12dB multimode filter is the desert island filter, simply awesome in a polyphonic synth. The classic OB-X had a fixed lowpass mode, the OB-R has lowpass, bandpass & highpass modes.
Panning VCA’s Each voice retains the classic 3080 OTA VCA but also includes a stereo panning VCA that can be modulated by several sources. The spread control make it easy to pan voices across the stereo field.
Envelope Generators Each voice has a dedicated analog ADSR for the filter and VCA. In addition there is a global five-stage DADSR with (20) modulation destinations.
Analog LFO’s Two global analog LFO’s with triangle, square and S&H waveforms can be sent to VCO1 frequency and pulse width, VCO2 frequency and pulse width, and filter cutoff.
Digital LFO’s Two LFO’s per voice with triangle, sawtooth, reverse sawtooth, square, and random waves with (20) destinations. LFO’s also have dedicated attack-decay envelopes and can be free-running or synced to the arpeggiator, sequencer, or MIDI clock for tempo-synced effects.
The heart of the VS-1 is a 600MHz ARM-Cortex-M7-based System on Module. The module integrates all memory and I/O interfacing.
16-bit DAC Together with the fast core clock the VS-1 updates scans the controls and updates 16-bit CV’s 4,000 times per second for smooth operation with no lag or stepping.
Key Modes The VS-1 is bi-timbral and supports single, split and layer modes. When in single mode the selected program controls all eight voices. In split and layer modes the voices are split into two groups of four voices called Part 1 and Part 2. In addition to typical Part settings such as split points and transpose, each Part also has an additional setting called Cards per Voice which determines how many voice cards are utilized per voice – options are 1, 2 or 4 cards max (8 cards is the same as unison).
Alternative Tunings The VS-1 supports (15) alternate tunings in addition to standard chromatic western.
Autotune The VS-1 makes use of a modern 16-bit DAC vs the 10-bit DAC of the classic. Together with the 600MHz core processor this allows for high accuracy control voltages. However, design limitations resulting in lower accuracy CV’s are responsible in part for the character of the vintage polysynth – so we have implemented two Autotune modes for Key CV’s. Low-Res mode tunes the voices at the same number of points and the same resolution as the OB-X. Hi-Res mode tunes the voices at many more points at 16-bit depth. In addition, the OB-X does not have auto-calibration of filter frequency and scale for each voice. The VS-1 includes this auto-calibration but it can be bypassed.
Polyphonic Sequencer Full-featured 64-step polyphonic sequencer with 240 patterns. Real-time and Step-Entry modes for easy programming.
Arpeggiator Modes include up, down, up/down, up/down (inclusive), as played, and random. Range between 1 & 4 octaves. An arpeggio can be recorded directly into a sequence pattern.
Chord Memory Chords can be programmed onto one key and played back with root pitch at Key C3.
Aftertouch MIDI Channel aftertouch can be routed to (16) destinations including VCO1 frequency, VCO2 frequency, filter cutoff, loudness, and LFO modulation amount. Eight velocity response curves have also been included to suit playing styles and to compensate for controllers with non-linear aftertouch response.
MIDI/MPE with polyphonic aftertouch is a stretch goal.
OLED High resolution display for visual feedback.
Main Audio Outputs—Unbalanced, 1⁄4 inch audio outputs. These are the main stereo outputs for the synth. They carry Part 1 and also Part 2 if no cables are connected to the Aux Audio Output jacks.
Aux Audio Outputs—Unbalanced, 1⁄4 inch audio outputs. Connect audio cables to these jacks if you want separate stereo outputs for Part 2 (for splits and Layers).
Audio Inputs—Unbalanced, 1⁄4 inch audio inputs. These are inputs to the filters of Voices 1 & 2. Each input has a preamp with gain.
CV & Gate I/O—Voice 1 only.
Filter CV Input—Part 1 only
Assignable CV Inputs—Assign to any parameter.
USB Host—Bidirectional MIDI communication with a computer. The VS-1 is a Class Compliant USB device and does not require additional drivers when used with Mac OS or Windows.
USB Peripheral—Direct connection to a usb-enabled midi keyboard controller.
MIDI In, Out, and Thru—Standard 5-pin MIDI DIN connectors.