GForce Software Oberheim OB-1 review, emulation of the first programmable analog synth

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Review: GForce Software Oberheim OB-1 is an authentic, souped-up emulation of the first programmable analog Synthesizer from 1978.

Dave Spiers and his British company, GForce Software, teamed up two years ago with the legendary Oberheim. The aim is to preserve the spirit of the Oberheim classics for posterity, not as hardware but as plugins, i.e., software. All this with the support of Tom Oberheim.

Some big stars from Thomas Elroy’s historical catalog have already been virtualized, including the 8 Voice (OB-E), OB-X, SEM, or the iconic DMX drum machine. Today, they’re adding another one to the list. This time, they’ve chosen a rare Oberheim synth that flies under the radar of many, the OB-1 from 1978.

GForce Software Oberheim OB-1

That’s quite a surprise. I would have guessed that the next GForce Oberheim collaboration would be a Matrix or OB-Xa emulation. Wrong, it turned out to be the OB-1, the first storable/programmable monophonic analog Synthesizer. 

GForce Software kindly sent me a license two weeks ago so I could test the new OB-1 for you. 

Oberheim OB-1

The original and the Oberheim OB-1 plugin are very classic in synthesis. Based on the SEM architecture, it consists of two multi-wave oscillators with sync and cross-mod options, a 2-pole/4-pole analog filter, LFO, and two ADSR envelopes.

A highlight of the original was the ability to program up to 8 patches and save them in the hardware’s memory—a novelty in 1978. GForce Software didn’t stop there for their endorsed emulation. They have given the virtual OB-1 more horsepower with new features and options. 

Classic UI

The GForce OB-1’s UI is perfect! The MK1 version inspires it, is very clear, and is fully scalable. You can immediately see the synth’s structure on the main page, with all the parameters—nothing hidden behind countless menus. Very hands-on and intuitive.

There is also a second selectable UI that gives you vintage OB-1 vibes. It removes most of the new features and only leaves the original ones. Okay, yes, not all but most. 

GForce Software Oberheim OB-1

GForce Software Oberheim OB-1

Unlike the Oberheim OB-1 1978, the plugin version is a polyphonic Synthesizer with up to 16 voices and mono unison. This fits the synth very well.

As with the original, the sound generator section consists of two multi-wave oscillators with control over the waveform and frequency. These are anything but simple, as they use combinations of mixable waveforms selectable with the dedicated switch.

The left position gives you a triangle and saw, the center inverse saw and sine, and the right narrow pulse, square in the center, and wide pulse. Mixing these makes achieving different wave shapes in the in-between results exciting.

Modulating the waveform mixing via the envelope or LFO gives even more timbre options. Frequency modulation (FM) for each oscillator, cross-mod at audio rate, and sync are also available. You can create FM, sync, or ring-mod-style sounds in just a few steps. 

From here, the signal then goes into the output section. The original had these in the unusual form of switches. In the plugin, GForce Software has implemented it more modernly as a classic oscillator mixer.


In addition to the levels of the individual OSCs, each oscillator has a mixable sub-oscillator that adds more power and bottom to your sound. Below is a noise generator with white, pink, or a mix of both.

With the VCA On switched off, you can bypass the VCA envelope; instead, each note press will open/close a gate.

Screaming Filter

The next step in the signal path is the filter. Unlike the Oberheim SEM with its state variable, the original OB-1 featured a pair of cascaded OTA-based 12dB/oct lowpass filters. GForce Software has also modeled this for the Oberheim OB-1 plugin with both 2-pole and 4-pole options.

You can control it with classic cutoff and resonance parameters. Nothing fancy new. Additionally, you have fine-tune for the frequency and key-track. One knob modulation for the cutoff is possible via the dedicated filter envelope or LFO.

It’s a unique filter, in my opinion. A color that you are not used to from Tom Oberheim synths. The filter screeches a lot at high resonance and becomes a wild beast. It can also be smooth but not like the classic SEM state variable.


Supercharged Modulation

Modulation is also onboard. In the modeled core, the GForce OB-1 emulation has the same modulation as the original: two ADSR envelopes and an LFO (sine, square, S&H) with a delay and rate control. GForce, however, has logically expanded them, making them more flexible.

The envelopes have a loop and retrigger function. This means that they are pseudo-LFOs. The single LFO now offers sync and a retrigger option as well.

That’s not all! GForce Software has once again drilled out the mod options by implementing the famous X-Modifiers. These are dedicated souped-up multi-wave LFOs and ADSRs for almost all parameters. They take the OB-1 sound into new wild areas. This should satisfy any modulation desire. 

I’m missing a simple modulation matrix where I can read all the mods directly. The color coding system is fast, but the matrix would be easier to read.


Finally, built-in effects refine the sounds. It includes a multi-FX processor with a handy high-pass filter with selectable 2-pole/4-pole, a multimode chorus, a stereo delay, and a rich, atmospheric reverb with filtering.


The high-pass filter is a nice addition that allows you to create thinner, more fragile sounds. There is little to say about the others. These can also be found in the other GF soft synths and have always been convincing—especially the delay and reverb, which transform every patch into spherical soundscapes.


The whole thing is rounded off with an arpeggiator and a sophisticated, vintage-style sequencer. The arpeggiator is straightforward, has swing, and offers various classic modes, including up, down, up/down, and random. Nothing special. 

The sequencer, on the other hand, is deeper and more fun. It has three sequencer lines, each with up to 16 steps and custom lengths. So, ready for polymetric sequencing. There is one for the pitch, one for the velocity, and another for macro 4. Yes, for automation of a macro control. Great for complex patterns.

Programming is easy. You can set each step either individually or live via keyboard input. Once done, you can playback them in various modes: forward, backward, for/back, and random.

GForce Software Oberheim OB-1 sequencer

Initially, it looked a bit difficult, but the programming was straightforward and fun after a short intro. Please check the factory patch library. It has some very impressive patches that demonstrate the sequencer capabilities.

Ratcheting or probability is missing, but randomization of the sequences at an interval is possible.

Patch Browser In GForce Software Oberheim OB-1

Talking about sounds. Like the previous GF plugins, it also includes the new patch browser. This can be accessed with one click and categorizes all available presets with dedicated tags: collection, category, types, timbres, and patch. 

It ships with over 300 stunning out-of-the-box presets from professional sound designers. I have to praise GForce Software for their selection of sound designers.

They did a stellar job here again. The built-in sounds are great and immediately inspire. They show nicely what is possible with the virtual Oberheim OB-1. 


You can find your classic basses, leads and juicy pads but also very experimental sounds that you would not expect from an “analog modeling synth.” I struggled to find anything wrong with the presets. OK, I found a thing. 

I would be happy to hear a little less effects in the patches. Many sounds live off of them. But it would also be nice to hear more of the analog modeling engine without the full effects boom.

Other Goodies

Not to forget that there are also four freely assignable macros. Each can have several parameters, allowing you to tweak multiple parameters simultaneously. Macro 4 can also be automated in the sequencer, which is neat, too.

Further, it includes programmable velocity responses, intriguing note pan modes, and mappable polyphonic aftertouch. I tested the latter with my Kontrol MK3 from Native Instruments. It responded perfectly to the input from the keyboard.

GForce Software has also added the famous vintage knob in the Oberhein OB-1 plugin and the bender of the original unit with different destinations.

Sound Demo

GForce Software Oberheim OB-1 Review

Dave Spiers and his team have created another outstanding Synthesizer plugin with the Oberheim OB-1. It has a powerful, rich analog-style sound with much character and energy.

Thanks to the many feature extensions the original didn’t have, many more sounds are possible here, from soft and elegant to brutal ones where the sync breaks out—a joy to play this virtual instrument. 

The new features make sense here and take the synth out of its comfortable simplicity into more mature areas. I also have criticism. I miss a simple modulation matrix where I can quickly read all the connections. That would be helpful, especially for the complex patches. 

However, I cannot judge the quality of the emulation. Since I do not own any Oberheim OB-1 hardware or have never spent much time with it, this is not a topic here. It sounds fat and rich, but like an OB-1? I don’t know, sorry. 

Also, there is no NKS compatibility. I noticed this when testing with my Kontrol Mk3 with polyAT, which is also currently in the studio for testing. It would be nice if GForce Software could add this as an update.

All in all, this is another impressive synth release from GForce Software and Oberheim. 

GForce Software OB-1 is available now for an introductory price of £49.99 + VAT instead of £99,99 + VAT. It runs as a VST, VST3, AU, and AAX plugin on macOS (native Apple Silicon + Intel) and Windows. It also ships with a standalone version. 

More information here: GForce Software 

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  1. Fantastic review. Congratulations to Gforce software on another incredible accomplishment on crafting a magnificent instrument from the Genesis from where the culture was started moving from the present into the great unknown.

  2. What would be interesting, is to see Oberheim implement some of these things into new real-world, future classic performance instruments? With expressive keyboards, knob-per-function layouts and minimal or no features buried in menus. True future classics. GForce is onto something really interesting here, I’ve got it and am just starting to dig into the possibilities. I’m imagining this as a real analog (polyphonic) instrument that I can touch and play. I’d way rather see this in the ‘hardware’ world, than yet another remake of 1982 with USB. As much as people are enjoying (rightfully!) the OB-X8, I’m way more excited at the possibilities represented by a ‘real’ “OB-Z” class of instruments that look and play like this. Any thoughts, Marcus Ryle?:)

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