TwinPath
User's guide

Introduction

TwinPath can be used to enable parallel effects processing, or as a replacement for host-specific methods to create such parallel setups.

It hides the details of managing multiple signal paths, and offers a compact, quickly accessible control interface. The result is a consistent setup you can easily recreate in any DAW, regardless of how each host handles audio routing.

Each complete TwinPath setup requires 3 nodes placed on the same stereo track. During placement, nodes automatically get grouped and assigned a new bus that's managed internally by the plugin.

User interface and automation parameters are contained in the 1st instance (controller node).
The 3 nodes will be referred to as a group throughout this document. Each group has its own bus (consisting of several parallel streams).

Placement, correctness & completeness

A TwinPath group will only process audio when the following conditions are met:

• All nodes have been placed (completeness)
• The nodes are on the same track, in the correct order, and they are not bypassed; there is no overoccupancy / duplication of roles (correctness)

The following are important notes and information regarding the creation and maintenance of a well-functioning setup. In summary:

Always use the built-in preset management system instead of host presets

Since some host applications don't properly distinguish between preset data and plugin state data, to prevent compatibility problems across many hosts, the plugin cannot reliably reject bus & node configurations saved in presets that may not fit the active project.

When using host presets instead of plugin-managed ones, this can lead to:

• Duplicated or incorrect node roles assigned in the same group, disrupting bus communication
• Turning groups into incomplete ones, disrupting subsequent creation of new groups (A newly placed controller could be mistaken for a missing piece from an already existing group)
• Breaking the "same track rule", potentially leading to severe problems even if various safeguards are employed by the plugin (like immediate bus shutdown)

Possible remedies if a host preset was accidentally applied, resulting in defunct groups:
While it's VERY STRONGLY advised to have the situation avoided in the first place, a manual repair may be attempted at the user's own risk - the plugin will attempt to do its best to patch things up, e.g. repair bus configurations once a conflicting node is removed.
Assuming there was just one preset load, simply deleting and re-instantiating the node in question should solve the problem. If this was the 1st (controller) node, you may want to save its state to a temporary preset using the plugin's own preset system - this however is only straightforward when the group is not deemed incomplete (otherwise the group needs to be completed first).

Always keep the 3 nodes of the same group on the same track

Even if the plugin appears to work with its nodes distributed across different tracks, it is contrary to the plugin's core mechanism of bridging its parallel processing to a sequential interface.

Non-sequential node layout carries a non-zero risk of various forms of audio stream and data corruption, even if the plugin comes with multiple safeguards and a failsafe bus shutdown mechanism.

Recommendation: complete all setup steps in one go (for each group)

It's a best practice to not interrupt a setup workflow and come back to it later. This way there is no possibility for accidentally leaving incomplete groups or making auto bus assignments violate the "same track rule".

User interface basics

The following information applies throughout the user interface:

• Default values:
  • Rotary knobs: double click/tap
  • Horizontal sliders: click/tap on the label above (when applicable)
• Quick preset save: long press on the preset name
  

Parallel lanes vs regular controls

The user interface blends a 2-way parallel layout with regular controls / indicators. Symmetries in the layout are the guiding principle to differentiate between the two.

Common elements

Monitoring

Monitoring allows checking the exact, unprocessed output of each subchain. This can be useful when editing effects, or when fine-tuning or diagnosing certain aspects of the merged output signal.

The monitoring toggles (labeled as "MON" on the UI) aren't designed to be performance controls, or as "solo" switches; they serve as a utility for accessing the verbatim streams before they are merged.

Subchain gain adjustment

Each parallel stream's gain can be adjusted within a range of -6 - 6 dB using the "GAIN A" and "GAIN B" rotary knobs. These are intended as fine-tuning controls; it's therefore recommended to set up the subchains to have comparable volume levels.

Dry/Wet level

As one would expect, this setting works on the group level. At the dry position, TwinPath will relay its original input, skipping all effects contained in the subchains.

Cross-fade mode

Cross-fade mode can be used to blend between Subchain A and Subchain B, using a single control (labeled "BLEND").

PRE / POST

In PRE mode, cross-fading is applied at the input stage, while in POST mode, blending is carried out on the subchain outputs.
The two modes can be very different when effects with large delays or feedback are used (in other words, in cases where an effect tail is produced). The MONITOR feature can be used to examine effect behaviour in different modes.

PRE mode is often recommended for long-tail effects. This configuration allows the effect decay to naturally wind down when the input is shifted to the other subchain, while blending the unattenuated tails together to serve as a versatile creative tool.

Dual mono mode

Dual mono allows independent effects processing on the two component channels in a stereo signal. In this mode, the level meter shows the output of the plugin, where differences in L/R peaks can be gauged and used as instant visual feedback when adjusting channel gains.

SHIFT

A smooth mapping change from L/R to M/S is supported via the SHIFT control.

Subchains are fed a mono signal (on a stereo bus) extracted from the dry signal based on the channel mapping.
When merging the subchains, the LEFT channel is taken from both streams (and a reverse channel mapping is performed).

BIAS

The BIAS slider is a stereo dry/wet control (with a 2x control curve steepness).
NOTE: gain adjustment is not applied to the dry signal (left channel at BIAS=1 or the right channel at BIAS=0).