
BaconPaul has released Six Sines, a free and open-source TX81Z that was inspired by the FM synth plugin.
FM synthesis is a somewhat divisive topic; some love it, some hate it, and others don’t understand all the fuss.
There’s no denying the power of FM synthesis, even if synths like the Yamaha DX7 gained fans and turned enthusiasts away equally.
Thankfully, things have moved on since the DX7, which had a notoriously convoluted workflow that would test the patience of angels.
Whether you love digital FM’s distinct character or find it too cold and harsh, the conversation never ends.
The recent release of Behringer’s BX1 (DX1 clone with CS-80-inspired filters) has the topic trending again, making it an ideal time for BaconPaul’s Six Sines.
BaconPaul is part of the awesome team behind Surge.
Six Sines is a free, open-source MPE-compatible, 64-voice, six-operator FM synth plugin for macOS, Linux, and Windows.

The interface provides a straightforward workflow that lets you start making interesting sounds immediately.
The top row of the GUI is where you can adjust each of the six operator ratios.
Clicking on any of these ratio controls will open a corresponding panel at the bottom of the interface, where you can select waveform types and set their phase, adjust a DAHDSR envelope, a multi-wave LFO, pitch, and modulation.
Sandwiched between the ratio controls and the bottom panel is an FM modulation matrix and operator mixer with individual level/pan controls (Main Level, Pan, and Tune controls are just above).
Waveshapes include sine, squarish, swish, and the original Yamaha TX81Z waveforms. The original Yamaha TX81Z waveforms have been revived recently, including Sonicbits Exakt late in 2024.
Six Sines comes to life through modulation; each operator can output audio, modulate itself, or subsequent operators.
“Each operator, operator modulation application, operator feedback, and operator level can be independently and individually modulated.”
Six Sines is currently in version 1.0.4 and receiving regular updates from the developer.
The plugin is available in AU, VST3, and CLAP formats for macOS, Windows, and Linux.
Returning to the Behringer BX1 for a second, how do you feel about the clone-after-clone strategy?
I can understand the strong reactions within the industry, but I’m always surprised at how much they offend some retail customers (albeit a minority, but it seems strange to me).
Download: Six Sines (FREE)
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