The OB-X and OB-Xa Analog Synths

Oberheim OB-X Synth

Oberheim OB-Xa Synth

8 Voices of legend

What happens when you take 8 mono synths and use them together? Huge analog sound! This sound is the result of slight imperfections between each voice card and, because of some electronic components (mis)behavior, parts from the orginal circuit (notably the OB-X) caused all sort of distortion happening at different stages from filter to VCA and also at the output stage, OB-Xtreme place a special attention to the later with an emphasis on "the Growl".

V2 is a full remake, while OB-Xtreme V1 was a simpler take on an OB voice card architecture, V2 is more closely related to original OB designs and specs (including features from OB-X, OB-Xa etc) it is not a direct V1 replacement, nevertheless it got a Legacy mode for Envelope Generators and Filter control so V1 sounds can be reproduced or made (more on that later).
V2 have higher specs in every part of the circuit, it comes as an upgrade gift to all V1 owners, V1 owners can update for free or use a "give what you want" option.

Get OBXtreme!

Main features

The summer 2022 pre release was the full functioning synth minus the v2 factory presets (only v1 bank + some extra were included, LFO2 wasn't active). Since then additional work have been done for Release version which features many improvments, more controls on voltage offsets (portamento offsets! you know you want that), more modulations and better logic. Design sounds and funk it up with some brass stabs, cutting leads, lush pads and screaming bass.

A complete list of OB-XTreme 2.0 features is provided below, in a nutshell OB-Xtreme can act as an 8 voice polyphonic, 8 voice unison mono or true (one voice) mono, a FAT mode engages the unison while also providing polyphonic unison, that means 8x8 voices power.
Most OB-X/OB-Xa functions are provided, including SAW, PULSE, TRI oscillators shapes and the peculiar SAW+PULSE which can produce an interesting +1 OCT harmonic depending on the pulse width setting.
the 2Pole filter is based on the OB-X and the 4Pole is based on the CEM3320 implementation, the 2pole has that classic SVF linear "singing" resonance across the bandwidth while the 4pole will resonate less at lower cutoff values (a bit Moog like), a bandpass output is also provided in 2pole mode while 4pole have an optional volume loss compensation.
The Xtreme factor is the main control over the emulated OTA enduced distortion, one chip in particular the CA3080 was used a lot at different places in the circuit (although less and less over the OB synths evolution). OB-Xtreme gives some control over that, you can push them way beyond the original specs or stay at minimum for more traditional behavior, you can also bypass PRE or POST circuits for versatility. The PRE stage will act more on lower notes while the POST stage is linear across the range.

Another feature is the under the hood access so you can control the 8 voice cards voltages across the main parts. The cards variations are an important factor to mimic the analog character, while using a VCM (virtual component modeling) approach, I wanted something effective but not time consumming so I designed some pre-defined offsets and deviations that you can dial in or scatter across all 8 voices.
You get seven macro sliders: OSC (which doubles on the front panel as the "SPREAD") controlling OSC 1 and 2 tuning offsets, FILT filter envelopes offsets, AMP for amplitude envelope offsets, VCF for VCF deviation, PW for pulse width offsets, PORT for portamento glide time lag and XMOD for cross modulation offsets. Additionally you can toggle a realtime small random deviation per note or randomize and scatter deviations around. Voltages offsets reflect on the GUI as positive or negative voltages (yellow/blue).
I removed a not so usefull temperature function that changed the EG timing to make room for individual card tuning, the cards tuning in semitone (+1 OCT range) can give interesting results, we can have a ressembling chord mode when using unison (FAT) mode.

All manufacturer and product names mentioned on this page are trademarks of their respective owners, which are in no way associated or affiliated with ALYJAMESLAB. The trademarks of other manufacturers are used solely to identify the products of those manufacturers whose tones and sounds were studied during ALYJAMESLAB sound development. All names of instrument and inventors have been included for illustrative and educational purposes only and do not suggest any affiliation or endorsement of OB-Xtreme by any company or instrument inventor

OB-Xtreme Videos & Sounds Demos Playlists (v1 + v2 coming up).

The Fat and screaming sound!

Product Demos by Aly james

OB-Xtreme Features and Details

  • Cross Platform 64bit capability (Windows VST3 and Mac AU(Audiounit).
  • 64bit build using latest OS and IDE(PC VisualStudio and Mac Xcode).
  • Updated GUI(graphic Interface) also now using high-res graphics and DPI awareness.
  • Rewritten and Refined sound engine.
  • 8 voices poly or mono unison with per voice PAN control and global stereo widening control, can also turn into real (one voice) mono or act as polyphonic unison (8x8).
  • Most of OB-X/OB-Xa functions added (OSC shapes, X-MOD, F-ENV, SYNC etc) on top of new modulation routing.
  • Enhanced oscillators spectrum and filter modes (2Pole/4Pole LowPass and 2Pole BandPass) based on OB 2pole SVF and CEM 3320 24Db, 4Pole can have an optional volume compensation.
  • Accurate SAW + PULSE OSC mixing (can produce +1 octave harmonic depending on the pulse width).
  • Up to x32 oversampling.
  • POST and PRE OTA (CA3080 chip used for VCA, Filter and Output Stage) variable distortion (Xtreme factor) with bypass.
  • x8 Voice cards voltage offsets and deviation can now be controlled easily by seven macro controls, optional random propagation and realtime deviation (per note).
  • Legacy modes for Filter modulation and EG/VCA shapes to match V1 sounds and behavior if needed, the default envelope/VCA behavior is the CEM3310/CA3080 combo (Linear VCA and exponential envelopes) while the legacy mode can be used for more snappy sounds (using an ultra exp VCA response).
  • Vibrato LFO, original LFO + additional LFO 2, Phase reverse option mode for LFO 1 & 2 (card 1,3,5,7) got phase reversed modulations, can also invert Keytracking.
  • LFOs have gate re-triggering option, SINE, RAMP, PULSE, SAW, TRI, S&H and Noise shapes, LFO2 can be BPM synced or act as a one-shot ramp (up or down) envelope.
  • LFOs can be set to single: one LFO on the main board for all voice cards or to multi: one LFO per card
  • Optional OB-X 6bit resolution on the Filter Cutoff knob scanning.
  • Sustain pedal can act normally or use the OB Mode (sustain like piano) controllable Envelope Release offset.
  • (Mac) Introducing new Mac Signed and Notarized Installers.
  • Basic internal preset browser with main categories.
  • OB-X (light mode) or OB-Xa (dark mode) changeable skins.
  • Cross Platform 64bit capability (Windows VST3 and Mac AU(Audiounit).
  • 64bit build using latest OS and IDE(PC VisualStudio and Mac Xcode).
  • Updated GUI(graphic Interface) also now using high-res graphics and DPI awareness.
  • Rewritten and Refined sound engine.
  • 8 voices poly or mono unison with per voice PAN control and global stereo widening control, can also turn into real (one voice) mono or act as polyphonic unison (8x8).
  • Most of OB-X/OB-Xa functions added (OSC shapes, X-MOD, F-ENV, SYNC etc) on top of new modulation routing.
  • Enhanced oscillators spectrum and filter modes (2Pole/4Pole LowPass and 2Pole BandPass) based on OB 2pole SVF and CEM 3320 24Db, 4Pole can have an optional volume compensation.
  • Accurate SAW + PULSE OSC mixing (can produce +1 octave harmonic depending on the pulse width).
  • Up to x32 oversampling.
  • POST and PRE OTA (CA3080 chip used for VCA, Filter and Output Stage) variable distortion (Xtreme factor) with bypass.
  • x8 Voice cards voltage offsets and deviation can now be controlled easily by seven macro controls, optional random propagation and realtime deviation (per note).
  • Legacy modes for Filter modulation and EG/VCA shapes to match V1 sounds and behavior if needed, the default envelope/VCA behavior is the CEM3310/CA3080 combo (Linear VCA and exponential envelopes) while the legacy mode can be used for more snappy sounds (using an ultra exp VCA response).
  • Vibrato LFO, original LFO + additional LFO 2, Phase reverse option mode for LFO 1 & 2 (card 1,3,5,7) got phase reversed modulations, can also invert Keytracking.
  • LFOs have gate re-triggering option, SINE, RAMP, PULSE, SAW, TRI, S&H and Noise shapes, LFO2 can be BPM synced or act as a one-shot ramp (up or down) envelope.
  • LFOs can be set to single: one LFO on the main board for all voice cards or to multi: one LFO per card
  • Optional OB-X 6bit resolution on the Filter Cutoff knob scanning.
  • Sustain pedal can act normally or use the OB Mode (sustain like piano) controllable Envelope Release offset.
  • (Mac) Introducing new Mac Signed and Notarized Installers.
  • Basic internal preset browser with main categories.
  • OB-X (light mode) or OB-Xa (dark mode) changeable skins.

Windows:

Windows 10 and higher, 64bit host, plugin provided format is VST3.
Not supported but has been proved to work on Windows 7.

Mac OS:

Mac OS (10.14) to Mojave or higher, 64bit host, plugin provided format is AU (AudioUnits).
Not supported but has been proved to work down to Mac OS (10.12.6).

About AudioUnits format:

AU is Apple s proprietary audio technology, part of the Core Audio provided by Mac OSX. It is part of the operating system so it provides low latency and system-level support for the interface. Most DAWs developed for Mac OSX support the Audio Units interface due to its stability and system-level solutions (which also means faster processing). Apple Logic only utilizes Audio Unit format plugins, but other DAWs such as Ableton can also use these.

One or two DAWs like for example Cubase do not support Audiounits directly yet but you can still easily load an AU plugin with the help of a VST host plugin, some popular solutions are DDMF Metaplugin or BlueCat's Patchworks, a popular free one that recently got open sourced is KUSHVIEW ELEMENT. You will find info and a direct link to latest free binaries at the support/OSX Support part of my website.

Protools:

Avid Protools only supports its proprieratary format AAX at the moment but you can still easily load an AU or VST plugin with the help of a VST/AU host plugin, some popular solutions are DDMF Metaplugin or BlueCat's Patchworks, others might be available that I am not aware of yet.

Other info:

32bit is not supported ATM
Mac M1 handles it fine (rosetta 2) even if not compiled for native ARM yet. Native ARM/INTEL as universal binaries as well as Mac VST3 format will come in next update.

Read the OB-Xtreme 2 Manual

Get amazing details about the OB Synth line and master the OB-Xtreme 2!

OB-Xtreme V2 Manual - coming up!

OB-Xtreme 2 User Manual


Owner of 32bit version 1.0 wants to upgrade?

GO HERE

Change Log

You can check your current version with a right click on the GUI.
Updates for OB-Xtreme 2.0 owners are free until version 3.0

pending - v3.0.0
  • Introducing - Mac VST3 and Native Silicon (M1/M2),builds are "Universal 2" meaning VST3 and AU work on both Intel x86-64-and ARM64 Apple Silicon Mac natively.
  • Introducing - Improved GUI, new design, crisper look at different DPI (HD graphics, Vectorknobs).
  • Fix - PWM not receiving full LFO range (voltage polarity fix)
  • Fix - In some cases OSC phase would reset on waveform change and cause a louder sound until it drifts again normally after a few notes.(phase init fix)
  • Fix - Rare crash on receiving legacy MIDI Program Change.
  • Fix - Improved CPU.
  • Fix - Improved VST3 MIDI support.

11/19/22 - v2.0.2
  • fix- GUI OSC Tuning knobs: no more dead spots and perfect sync
  • fix- GUI Cards OSC Deviation indicators: now update voltages even if not playing
  • OSC Tuning in semitone now displays over OSC's tune knobs when clicked or turned
  • Little CPU reduction

09/29/22 - v2.0.1 release
  • Add v2 factory presets, activate LFO2
  • LFO2 Modes (LFO, BPM Synced, One-Shot Envelope)
  • LFO2 modulation and routing activated (SPREAD, WIDTH, MIX2, MIX3 etc..)
  • Add semi-tones tuning per voice card
  • Vibrato delay time corrected
  • Added preset nav < -> arrows on the main panel
  • Add Portamento voltage offsets and Glissando mode
  • Add XMOD voltage offsets
  • DC filter (20 - 50Hz) control is now available for the end user adjustment (can tame low-end)
  • Re-worked CARDS panel controls
  • Most parameters are now automatable and save state
  • fix- Pitch-Wheel voltage going down briefly when selecting OSC2 ONLY until next trigger
  • fix- EG attack stages now receive voltage offsets correctly
  • fix- wrong LFO voltage on PWM 2
  • fix- GUI filter modes buttons logic now reflect setting (band-pass is only available for the 2Pole SVF)
  • fix- Corrected V1 Presets using wrong legacy settings
  • fix- Corrected LFO S&H rate (was half-time)
  • Code tidy minor CPU reduction
  • HD mode setting is no more reset by preset loading/changing
  • Place holder for a future 4 steps modulation sequencer or whatever it will become

07/16/22 - v2.0.0 pre-release (only missing v2 factory presets and LFO2 not active)
  • Cross Platform 64bit capability (Windows VST3 and Mac AU(Audiounit).
  • 64bit build using latest OS and IDE(PC VisualStudio and Mac Xcode).
  • Updated GUI(graphic Interface) also now using high-res graphics and DPI awareness.
  • Rewritten and Refined sound engine.
  • 8 voices poly or mono unison with per voice PAN control and global stereo widening control, can also turn into real (one voice) mono or act as polyphonic unison (8x8).
  • Most of OB-X/OB-Xa functions added (OSC shapes, X-MOD, F-ENV, SYNC etc) on top of new modulation routing.
  • Enhanced oscillators spectrum and filter modes (2Pole/4Pole LowPass and 2Pole BandPass) based on OB 2pole SVF and CEM 3320 24Db, 4Pole can have an optional volume compensation.
  • Accurate SAW + PULSE OSC mixing (can produce +1 octave harmonic depending on the pulse width).
  • Up to x32 oversampling.
  • POST and PRE OTA (CA3080 chip used for VCA, Filter and Output Stage) variable distortion (Xtreme factor) with bypass.
  • x8 Voice cards voltage offsets and deviation can now be controlled easily by five macro controls, optional random propagation and realtime deviation (per note).
  • Legacy modes for Filter modulation and EG/VCA shapes to match V1 sounds and behavior if needed, the default envelope/VCA behavior is the CEM3310/CA3080 combo (Linear VCA and exponential envelopes) while the legacy mode can be used for more snappy sounds (using an ultra exp VCA response).
  • Vibrato LFO, original LFO + additional LFO 2, Phase reverse option mode for LFO (card 1,3,5,7) got phase reversed modulations, can also invert Keytracking.
  • LFOs have gate re-triggering option, SINE, RAMP, PULSE, SAW, TRI, S&H and Noise shapes, LFO2 can be BPM synced.
  • LFO can be set to single: one LFO on the main board for all voice cards or to multi: one LFO per card
  • Optional OB-X 6bit resolution on the Filter Cutoff knob scanning.
  • Sustain pedal can act normally or use the OB Mode (sustain like piano) controllable Envelope Release offset.
  • (Mac) Introducing new Mac Signed and Notarized Installers.
  • Basic internal preset browser with main categories.
  • OB-X (light mode) or OB-Xa (dark mode) changeable skins.
10/05/14 - v1.1
  • Small bug fix
10/01/14 - v1.0
  • Initial release.

Get It !

Get OB-Xtreme 2 for PC & MAC

OB-Xtreme 2.0 comes with both PC & Mac Installers and Manual
*works on Mac M1 even if not native ARM yet (see compatiblity info tab)