Eternal Engine MARS is a new polyphonic tube Synthesizer with four oscillators from the makers of the Apparatus duophonic tube synth.
2023 is already two years behind us. It’s almost that long ago that the developers of Eternal Engine introduced Mars. It’s not the planet Mars but a new polyphonic tube Synthesizer.
The Mars Synthesizer is now ready for shipping. The features are also official.
Eternal Engine MARS
The MARS is a compact, 5-unit high rack format 4-voice polyphonic analog tube Synthesizer. According to the developers, the audio signal path is based on their previous APPARATUS duophonic Synthesizer. Mono, duo, and 4-voice polyphony modes are available.
Eternal Engine MARS features four oscillators with four distinct operation modes: basic with single, triangle, sawtooth, fixed pulse width (1/2, 1/4, 1/8), pulse, ensemble, and a noise mode with highpass and lowpass filters. They are based on the R-2R DAC TDA1387 and offer PWM and FM.
Then, it goes into a voltage-controlled tube filter of the second order with cutoff, resonance controls, self-oscillation, and overload function. The VCA, or voltage-controlled amplifier section, uses a traditional architecture of tube opto compressors.
MARS also offers a triode asymmetric overdrive to spice up the signals even more. The highlight of the Eternal Engine MARS is the four vacuum tubes included in the delivery. They give the synth a unique, crunchy timbre.
The heart of the modulation engine is a 4-slot/channel modulation matrix. This can be operated directly on the interface without menu diving.
The mod engine features two HADSR envelope generators with pre-delay and multiple retrigger options. Further, it houses an LFO with smooth waveform morphing (sawtooth-triangle-sawtooth, pulse-square-pulse), a sample and hold generator, and noise with reconfigurable highpass and lowpass filters.
Portamento and legato with auto and continuous modes are also onboard. However, there is no arpeggiator or sequencer.
Connectivity
On the backside, you have a 5-pin MIDI interface (in/out), a USB port with galvanic isolation, a master output, a phone socket, and an external input. The latter allows you to route and process audio signals through the tube engine.
It hosts a power supply input and four CV gate connections to integrate the synth with Eurorack and other analog setups. Eternal Engine also says a dedicated plugin will give you full software control (DAW control) over the synth.
A funny detail is the display on the left side that uses Nixie lamps.
First Impression
The MARS is an exciting polyphonic analog Synthesizer with special feature set and look. In terms of features, it’s not an all-rounder, and there are many synthesizers that can do more. However, the special feature here is the tubes and the unique signal path. That makes it very original and unique.
Yes, it’s a niche, special-interest synth, and I’m glad someone has brought it to market. It sounds lovely and rich-flavored. I attached the latest sound demos.
Eternal Engine MARS is shipping now. It’s available from the official website and costs $2199 + VAT + shipping.
Article From March 9, 2023
Countless synthesizers revive designs from the past. However, the unusual, experimental synths often inspire most to think outside the box. Plus, they bring the market forward. For me, they bring new ideas to the table that you don’t see in synths from the big players. That was also the case with the Apparatus from Eternal Engine, a crazy vacuum tube-based duophonic Synthesizer.
From the same developers comes the MARS, the polyphonic brother of the Apparatus—a different synth and different designs, but with the same tube concept.
Prototype
At the time of writing, the Eternal Engine has not shared any details about its polyphonic tube synthesizer. Only two videos are available that give a first sound impression of the prototype. The developers are currently working on the firmware.
I like the layout of the MARS very much. It’s very straightforward and well-structured. You don’t see it in the picture, but it probably has an oscillator block, filter, etc. A more classic subtractive setup. In the picture, we can see four tubes. It’s probably a four-voice synth where each voice has a tube.
What will make this synthesizer special are the built-in tubes. These have already given the crunchy, rich saturated sound character to the Apparatus.
Here is a little demo of the new hybrid tube synthesizer. The hardware part of the synthesizer is ready. Now we are finalizing the firmware.
I’m looking forward to seeing the final version of the synth. If all the features are right, the synth calibrated, it could have an epic sound. But let’s see how it will evolve during the development the next months and how the final product will sound.
Eternal Engine MARS availability and price TBA.
More information here: Eternal Engine
Would love to hear more sounds. The “Space Solo” sounds great, but a few of those filter sweeps seemed a bit clunky at times. Could not tell of it was operator or the synth itself.
I have no problems with limitations as long as the sound is interesting, and functions like a musical instrument. Synths are great for sound exploration, but I feel like some of the all in one synths currently are a little cartoonish. Looking forward to hearing what this is capable of in higher-def recordings.