Save Up to 30% on Our Catalog of Used & Vintage Gear! Shop Now Save Up to 30% on Our Catalog of Used & Vintage Gear! Shop Now Save Up to 30% on Our Catalog of Used & Vintage Gear! Shop Now Save Up to 30% on Our Catalog of Used & Vintage Gear! Shop Now

Tiptop Audio's ART of Modular Polyphony

A New Paradigm for Eurorack Modular Patching

Jacob Johnson · 05/11/23

Tiptop Audio has been making waves for the past couple of years with their line of Buchla designs in Eurorack format. But at Superbooth 2023, Tiptop is proving that they're not only bringing the past into the present, but they're also thinking ahead and boldly stepping into the future of modular synthesis.

For their showcase in Berlin this year, Tiptop has unveiled a new line of ART modules boasting incredible tuning precision and, perhaps to the interest of most, true polyphonic patching capabilities. Between the new ART communication protocol and their new Polytip format of patch cables, there are a ton of new ideas being revealed that challenge the conventional norms of modular synthesis.

In this article, we'll give some background as to what ART is all about and the challenges that it aims to solve, as well as provide an overview of the new modules. As you'll come to find out, ART was designed to be as elegant and streamlined as possible, while still open-ended enough to maintain the spirit of modular synthesis.

The Challenges of Tuning Modular Synthesizers

Tuning is an important process for any instrument, and given the vast sonic range and capability of a modular synthesizer, tuning may be one of the few common threads between otherwise completely different elements in a patch. For the solo performer, improviser, or anyone that simply records their patches down to a single stereo track, this process is usually fairly straightforward: tune all your oscillators and voices to be in tune with each other, and that's it! Of course, this process can become more elaborate in exceptionally large systems and/or those with unquantized analog sequencers, but tools like MIDI-CV converters and pitch quantizers can help.

However, when it comes time to jam with a friend, incorporate non-modular gear, or even just lay down overdubs on a previous recording, the difficulties of modular tuning become a bit more clear. Even with quantizers and other digital pitch modules, you will still need to make sure that your oscillator's base frequency is in tune with the instruments you're working with. Unlike MIDI, voltage is completely relative as a base for pitch—1V could be A440 or it could be middle C, all depending on how the oscillator is tuned.

Being conscious of your oscillator's tuning is an easy habit to get into, but that's only one potential concern. Certain modules might only track well within certain note ranges and thus will begin to deviate from being "in tune" when pushed beyond that range. Temperature drift can also be a real concern, where tuning an analog oscillator again at a later point after setting up might be necessary. Furthermore, recalling a previous patch and dialing in the tuning again can be a real hassle, and frustrating when, despite your best efforts, the new layers are not in tune with the prior recordings.

The Challenges of Polyphonic Modular Patches

We've talked about creating polyphonic modular synthesizer patches a couple of times in the past, both in using traditional methods and contemporary solutions. It's not impossible, but the amount of work and planning involved is certainly much more than just pulling out a dedicated polysynth. That said, the creative possibilities are well worth the effort for some, though there are definitely some concerns worth keeping in mind, regardless of your chosen approach.

On one hand, true polyphonic patches are often prohibitively expansive and expensive. For even a simple eight-voice subtractive synth, you'll need eight oscillators, eight filters, eight VCAs, and eight times as many LFOs and envelope generators are desired. There's also the problem of voice allocation, usually requiring a system of switches or shift registers, and all of those potential tuning issues mentioned above are multiplied for all of your voices. This can be physically and financially overwhelming, and despite the appeal of a modular synthesizer's patchability, the practicality of a hardwired keyboard synth is clear.

On the other hand, modern options reduce the size and complexity of patches required for polyphony, but these conveniences come along with compromises. Macro chord-type oscillators are very fun for pads and can be flexible with their array of chord types and voicings, but they're not the best choice if you're aiming to recreate the seamless, weaving voice-leading techniques of orchestras. Additionally, these and other approaches using samplers and physical modeling voices usually lead to consolidated signal paths that share filters, envelopes, and other elements. While we love a good paraphonic patch, it's not the same as true polyphonic control.

Ideally, a solution that consolidates the size and amount of patching for polyphony would be perfect. And if there was also a way to remove the concerns of tuning and voice allocation, polyphonic modular systems would be way more streamlined, allowing the user to focus more on the fun aspects of patching. As it turns out, Tiptop Audio's new ART system manages to make it all possible in a way that's easier than ever before.

ART: An Ecosystem for Stable Tuning And Polyphony

Tiptop Audio began ART development as a solution to the tuning woes of Eurorack modular synthesizers. But it also ended up being perfectly suited to the creation of polyphonic patching systems, too. Tiptop has long had polyphonic Eurorack systems on their mind, even showing a prototype oscillator concept with multi-core patch cables over ten years ago at NAMM 2012. Things have come a long way since then, with the introduction of the ART protocol and the Polytip patching format serving as the catalyst for an all-new line of Tiptop modules.

Tiptop Audio's P3000 prototype shown at NAMM 2012 Tiptop Audio's P3000 prototype shown at NAMM 2012

So, what is ART? Like MIDI, ART is a digital protocol for note data including note on/off, velocity, pitch bend, and more, but the rate of transmission is over 40 times faster than MIDI. This means that there is minimal latency, just as you'd experience in patching with analog signals. ART also features a streamlined method of configuration compared to MIDI, with all channel setup and allocation handled internally by ART control modules and compatible oscillators. And since ART messages are absolute pitch references, just like MIDI, tuning is always consistent.

ART messages are sent over standard Eurorack patch cables, so they're as easily patched and distributed as 1V/Oct and other modular signals—fully compatible with passive multiples and stackable patch cables. But it's important to mention that ART is very much not the same thing as analog 1V/oct signals, and trying to use ART signals on incompatible oscillators won't yield usable results. As such, getting started with ART requires both compatible oscillators or voices as well as dedicated ART controllers.

An Overview of the First ART Modules

The ART protocol was designed to achieve a balance of simplicity and flexibility, and as such there are a few different ways to get started with it. More modules are in the works, but this initial batch establishes the basic conventions of ART systems: a central ART controller either coordinating a number of discrete polyphonic voices in the traditional modular sense or working with some of Tiptop's new consolidated polyphonic modules.

Let's begin with OCTOPUS, the first of Tiptop's ART controllers. At first glance, this looks like a regular MIDI-CV converter, but rather than producing 1V/Oct voltages, it translates MIDI data into ART messages along with velocity control voltage. OCTOPUS provides a number of configuration modes that group its eight channels into any combination of polyphonic or multi-mono settings. In Poly configurations, messages will rotate between different channels to work with individual monophonic voices, combining them into a polyphonic unit. Otherwise, ART channels correspond to MIDI channel numbers, so connecting MIDI sequencers, controllers, or DAWs allows you to easily control connected elements.

To build discrete polyphonic voices in the traditional modular way, Tiptop currently offers two different ART-compatible oscillators: ATX1 and VORTEX. ATX1, a solid analog oscillator, is a shining example of how ART can eliminate the difficulties of tuning. When connected to OCTOPUS, ATX1 is able to analyze the environment of your modular case, accounting for temperature and heat to maintain stable tuning. Of course, it's still very patchable, supporting FM and hard sync, and Tiptop designed ATX1 to still exhibit enough of that "analog" feeling to not feel sterile.

VORTEX, on the other hand, is a digital wavetable oscillator with ART support. Like ATX1, it's a single, discrete voice that can be combined into polyphonic units with other ART modules. VORTEX features vintage digital-analog converters for a legacy-flavored sound, and it comes pre-loaded with numerous wavetables, but an SD card slot supports user waves to be loaded. Of course, you can select and modulate the position of the wavetable either manually or with control voltages.

A point worth mentioning here is that you won't find gate outputs for note events on OCTOPUS—instead, Tiptop has placed these on the oscillators themselves! We don't usually think of oscillators as the source of gates or triggers, but the implementation of ART makes this the most sensible place for voice gates to be found. This allows for the components of voices to be placed closer together in a rack and thus patched within themselves, rather than stretching cables all over your case. And as we'll soon see on the more complex ART modules, this is going to be really helpful for keeping things tidy.

In the context of subtractive synthesis, completing a full voice traditionally requires two envelope generators. One usually controls the filter, while the other is an amplitude manager connected to a VCA. To facilitate this arrangement in a compact package, Tiptop's CONTROL PATH contains all of these (except for the filter itself). The incorporated VCA is controlled by the right ADSR envelope, while the left may be patched out to a voice's filter or even something like the VORTEX wavetable position. In any case, both envelopes may also receive Velocity CV input for level control—in the case of ART systems, this would probably come from OCTOPUS.

As we've seen so far, Tiptop is providing everything you need to grab a handful of oscillators, CONTROL PATHs, and your favorite filters to build discrete voices. But of course, even with these considerations for patching and voice management, building out eight full voices would still be a sizable endeavor. For the space-conscious patchers out there, Tiptop Audio has another solution for you that seamlessly works with ART's capabilities: Polytip.

Polytip: A Polyphonic Module Patching Format

That's not a USB port on your module, that's Polytip! Well, technically it is a USB-C connector, but Polytip is a different specification: it's a compact, multi-core cable designed by Tiptop Audio for polyphonic patching. The choice of USB-C as the connector comes from their universal availability, and given recent tech mandates in the European Union this was a long-term consideration as well.

Polytip makes its debut on a few new Tiptop Audio designs: the ART-compatible VORTEX 6 oscillator, the OCTOPASS eight-voice lowpass filter, the OCTOSTAGES eight-voice ADSR envelope, the HEXAGAIN six-voice VCA, and the bidirectional OCTO I/O breakout adapter. These are all true polyphonic modules, but Polytip greatly reduces the number of cables required for patching.

Hang on—how does ART work in polyphonic contexts? Just like MIDI, ART messages are just data, and it's up to the receiving module to interpret and handle it. If you've ever tried playing chords on a keyboard monosynth, you'll know that you won't get chords out of it, no matter how hard you try. Instead, there's some note priority at play—usually playing the most recently received note. For monophonic ART modules like ATX1, the exact same result will occur, which is why OCTOPUS supports channel groupings. But for polyphonic ART modules like VORTEX 6, there's an internal voice allocator which distributes notes accordingly. That's why, even for VORTEX 6, you only need a single, standard patch cable for ART.

More than just an expanded VORTEX, VORTEX 6 is described as a PPG Wave 2.2-inspired polyphonic oscillator. This module has the unique distinction of featuring an ART input, as well as both discrete 3.5mm patch points and Polytip connections for its voice audio and per-voice gate outputs. This means that you can easily use your favorite existing collection of modules with its polyphonic capabilities, but the option to get into Polytip is always there.

To make complete polyphonic voices with Polytip patching, you can utilize the OCTOPASS, OCTOSTAGES, and HEXAGAIN modules. As you would find on a keyboard polysynth, these modules feature global controls that affect all voices, but there's still the ability to route audio and control signals independently via Polytip connections. OCTOPASS is eight 2044-style lowpass filters packed into one module, OCTOSTAGES is eight ADSR envelopes with velocity control, and HEXAGAIN is a six-channel VCA that supports simultaneous use of Polytip and 3.5mm patching.

Of course, there are plenty of situations where you might want to get signals in and out of the Polytip format. Bringing multi-channel control voltage modulation sources into Polytip can be incredibly valuable, as well as breaking out Polytip audio signals for further processing through effects or external mixing. This is where the OCTO I/O adapter comes in handy, supporting bidirectional conversion between 3.5mm and Polytip formats.

The Joy of Patching

This is only the beginning for ART and Polytip—Tiptop Audio is already mentioning that other ideas and concepts are in the work. Even just in this initial collection of modules, we think that the potential for really interesting polyphonic systems is clear, and it's likely a dream come true for anyone with polyphonic patching on their mind.

We're curious to see the other ART and Polytip modules that Tiptop has in development, and we especially hope to see these formats adopted by other Eurorack designers. After all, Eurorack became the thriving hub of ideas and cutting-edge designs that it is today thanks to the collective work of so many different minds—introducing ART and Polytip into this sphere is sure to be yet another way to create some really interesting things.