Review: BIAS X AI-powered guitar tone creation platform by Positive Grid

Josh of NoiseQuest returns to share his thoughts on Positive Grid’s BIAS X guitar tone platform.

Summary

Positive Grid ushers in a new era for its flagship amplifier, cabinet, and effects simulation. Equipped with newly developed modules, modern workflow enhancements, a refreshed interface, and an innovative Agentic AI (Artificial Intelligence) copilot, BIAS X attempts to redefine guitar and bass production.

Pros:

• Newly developed, AI-modelled effects and amplifiers are improved and noticeably more lifelike.
• The Agentic AI is well implemented, offering a fun and rewarding way to interact with the plugin when creating processing chains.
• Users can import custom Impulse Responses (IRs).
• MIDI (Musical Instrument Digital Interface) and Automation Mapping is intuitive.

Cons:

• No backwards compatibility for presets from previous generations (e.g. BIAS FX2).
• No dedicated amplifier or rig capturing functionality.
• No presets for the individual components (e.g. Amplifiers, Cabinets, and Effects).
• No preset snapshots to swap between different parameter configurations within the same patch.

Intro

Originally founded in 2013, with headquarters in Silicon Valley (United States) and Taipei (Taiwan), Positive Grid has undergone a noticeable shift in strategy and direction since their inception. Having always embraced the latest technological advancements to enhance creative workflows and streamline guitar/bass production, the company’s early software and hardware products prioritised deep control, customisation, and creative exploration.

Tools such as BIAS Amp, BIAS Pedal, BIAS FX, BIAS Head, and Tonecloud, established a symbiotic ecosystem designed for modern workflows, deservedly garnering a loyal following among hobbyists and professionals alike. Whilst this approach encountered challenges, with Positive Grid being scrutinised for slow development, confusing pricing structures, and convoluted upgrade paths, users had ultimate control across an integrated system that laid the groundwork for a promising future. A groundwork that enabled users to create virtual amplifiers and pedals from the component level, before building rigs and presets that could be shared with the wider online community for studio use and live performance.

As Positive Grid has matured, their strategy has evolved to prioritise convenience, mobility, immediacy, and ease-of-use, thus leading to the stagnation of the aforementioned products in favour of a new catalogue–principally, the Spark range of amplifiers and accessories, and BIAS X. Considering the rapid adoption of AI, this likely represents a smart shift by Positive Grid, who deserves credit for making these adjustments without sacrificing quality. It has, however, been an uncomfortable transition for those who invested in the company’s early products, which have either been sunsetted or are nearing the end of their lifecycle. One of the major pain points is the lack of backwards compatibility, which prevents users from accessing their previously created presets within the new products. Such a strategy was always unlikely to endear loyal customers, so it’ll be interesting to see how Positive Grid navigates this new chapter.

Below, we explore BIAS X–the brand’s flagship software suite that’s been revamped to mark the beginning of their new era.

Design & Features

Users familiar with previous iterations of BIAS FX will notice that the interface has undergone a significant overhaul. BIAS X provides an environment that is clean and easy to navigate, with subtle animations that help to orient the user.

The sharper graphics bring the components (e.g. Amplifiers, Cabinets, and Effects) to life, creating an experience that is both immersive and visually pleasing. There is also a noticeable “snappiness” to the plugin, which feels light and responsive in comparison to the sluggishness of previous generations. Divided into five distinct panels, the interface adheres to the following structure:

1. Side Panel (Red Box): From top to bottom, this panel provides access to the Preset and Gear menus, the Agentic AI copilot, and the plugin settings.
2. Header (Blue Box): Access to preset saving, undo/redo actions, DSP (Digital Signal Processing) monitoring, and MIDI and Automation Mapping.
3. Top Panel (Green Box): The Signal Chain. Here, users can add and reposition components (Amplifiers, Cabinets, and Effects) via drag and drop.
4. Main Panel (Purple Box): The currently selected components on the signal chain are visible in this panel, whereupon their parameters can be edited and automated.
5. Footer (Orange Box): Important global controls are located here, including Input and Output controls, a Noise Gate, and a Tuner.

Navigation

Navigating BIAS X’s environment is a breeze. As demonstrated by the GIF below (click to play), components can be selected simply by clicking on the signal/processing chain, and they can also be repositioned via drag and drop.

The main panel will update to reflect an expanded view of the selected component, making it easy for users to edit and explore the module’s settings. The interface is well-designed and highly responsive, with the lack of context menus and buried windows making for a pleasurable user experience. Given that there is an abundance of components/modules to explore, it would be convenient for each one to possess individual preset menus.

Being able to store one’s favourite settings for each component would be a major workflow enhancement, so it’s unfortunate this feature is missing. Likewise, it’s also not possible to save multiple parameter states within each preset. Whilst the undo/redo functionality helps to correct any unintended mishaps, not being able to seamlessly switch between different states within one preset–for example, when switching effects for different song sections (e.g. Intro, Verse, and Chorus)–feels like an oversight.

Presets & Components

As mentioned earlier, the left panel houses BIAS X’s Presets, Components (labelled as ‘Gear’), Agentic AI, and Settings. Preset management (see image below) is straightforward, with options for Factory and User-created presets.

Those familiar with previous generations will notice that Positive Grid’s community-driven Tonecloud is missing. The omission of this feature is a consequence of BIAS X’s inability to load presets from earlier versions of BIAS FX, which undermines what was once a highly engaged social community. It remains to be seen whether a new iteration of this concept will be implemented in future releases, as this was a valuable way to engage with the community and explore alternative processing chains.

BIAS X’s Gear list (see GIF below) features a comprehensive selection of components (Amplifiers, Cabinets, and Effects).

With over 120 components available, virtually every imaginable genre is catered for, so users are really only limited by their imagination when it comes to constructing their desired processing chain. It’s also worth noting that the same component can be loaded into the processing chain multiple times, which is particularly useful when using the Splitter (discussed later), or when layering effects for creative and experimental sound-design.

Effects

With a selection of 63 AI-modelled Effects (see image below), BIAS X is an excellent sandbox for sonic experimentation. From dynamics processing, to equalisation, saturation, modulation, reverb, delay, and beyond, BIAS X offers a suite of high-quality effects that excel at a wide range of processing tasks.

In addition to the ubiquitous pedal-style effects seen in the previous image, BIAS X contains emulations of popular effects and processing modules, such as the API 2500 Bus Compressor (see image below), Roland Space Echo, and Binson Echorec.

Whilst these emulations aren’t as exacting as dedicated plugins from other developers, their inclusion makes it easy to add extra polish and cohesion to a guitar/bass mix. They also contribute to BIAS X’s versatility, adding to its credentials as multi-effect for other instruments and extending BIAS X’s utility beyond its intended application. Overall, the effects are well crafted, with the advanced AI-modelling bringing depth, dimension, and realism to the resulting audio.

Amplifiers

With 33 Amplifiers (see image below) split across five domains (Low Gain, Mid Gain, High Gain, Acoustic, and Bass), BIAS X has an amp to suite every flavour and genre.

The improvement in sound quality over BIAS FX2 is immediately noticeable, with emulated options ranging from rare vintage icons to modern classics. It remains to be seen whether Positive Grid will add more emulations as the plugin evolves, but the current selection serves as a solid and versatile foundation. It’s worth noting that users will get the best results by following sound gain staging principles and not clipping BIAS X’s input, which can be monitored in the plugin’s footer. Whilst this is essential for optimal results that maintain high fidelity, overloading the input can be highly effective for creative sound-design, so experimentation is advised and encouraged–provided it’s done with intention.

Cabinets

BIAS X features 27 Cabinets that have been created in partnership with Spectre Digital. They are integrated directly into the signal chain (see image above) and are automatically assigned to match the chosen amplifier, though they can easily be swapped out for other options via the gear list.

As expected, users can also select between different microphone types and placements, and they can also load custom IRs into the plugin. Overall, this is an excellent implementation that seamlessly integrates with BIAS X’s workflow. Due to their complexity, cabinet simulations can often feel clunky and laborious to configure, but BIAS X bucks this trend in favour of a light and frictionless experience. As with the other components, the quality of the cabinets is worthy of acknowledgment, adding a convincing sense of depth and lifelike dimension to the signal chain.

Splitter & Mixer

The use of parallel processing chains has become an industry staple as amp sims have exploded in popularity, so it’s no surprise to see this feature implemented in BIAS X (see image below).

Users can create one split per chain, which is positioned before the amplifier (green box). A Mixer module is inserted at the point where the parallel chains merge (blue boxes), with options to balance the volume and the panorama of the two signals. Users can populate the chains with different effects, which is an excellent way to enhance stereo width, or create complex, layered effects.

Whilst this feature covers an essential function in modern workflows, Positive Grid missed an opportunity to go the extra mile with this feature. As such, there are no options for advanced routings (e.g. Mid/Side), and it’s not possible to create more than one split within the chain.

Artificial Intelligence

Situated unassumingly in the bottom-left corner of the Side Panel, BIAS X’s Agentic AI brings a new dimension to plugin interaction, and it is little wonder that this innovation stole the headlines upon the release of the plugin.

Embracing the global trend that has seen the widespread adoption of Large Language Models (LLMs)–such as ChatGPT and Claude–across multiple industries, Positive Grid has opted to build this functionality into BIAS X. The principle motivation behind this decision is to help users accelerate the time it takes to bring their ideas to life. By conversing with the AI in natural language, users can describe their desired mood, tone, gear, and timbre. The AI will then populate the signal chain with components that match the description, therefore acting as a copilot that reduces the creative barriers many experience when trying to sculpt their tone. Notably, the Agentic AI allows for continuous conversation, so users can keep tweaking their description until they’re happy with the final result.

Though it’s not possible to route audio into the chat directly from external sources (e.g. Apple Music, Spotify, and YouTube, etc.), audio files can be uploaded, whereupon the AI will attempt to match the sonic characteristics of the file. Although the results vary depending on the audio source, BIAS X performs admirably and convincingly when the guitar part is soloed or clearly audible. Again, users can continue to request changes after the audio file has been uploaded, so there is ample opportunity to customise the final result.

It’s important to note that BIAS X will create the generated processing chains from the existing components within the plugin, altering their settings to approximate the desired tone. In that sense, the AI offers genuinely insightful exposure to modules that users might typically overlook, therefore serving as a brilliant educational tool that acquaints users to different effect combinations and routings. Far from being a gimmick, this feature adds genuine value and serves as a tasteful example of how AI can supplement one’s workflow whilst avoiding the controversy associated with purely generative AI tools.

Given the inherent power of this feature, it’s surprising that Positive Grid hasn’t directed its potential towards Amp/Rig Capturing. Whilst the ability to read audio files offers an alternative workaround, the lack of dedicated capturing prevents BIAS X from matching the features provided by IK Multimedia’s TONEX and Overloud’s TH-U, which may deter some users from exploring the platform. Finally, it’s worth noting that BIAS X must be connected to the internet to make use of the AI, as no local option is provided. Despite this, the plugin will continue to work and users can always access their previously saved presets when offline.

In Use

Agentic AI aside, guitarists and producers familiar with virtual amp sims will feel right at home when using BIAS X. The user experience embraces industry conventions, thus ensuring a smooth transition from other plugins and eliminating any steep learning curves. Incorporating Amplifiers, Cabinets, and Effects into the signal chain and editing their parameters is straightforward, thus reducing friction and simplifying the creation of custom processing chains. Importantly, BIAS X handles MIDI and Automation Mapping with relative ease, both of which allow for organic and human expression when animating effect chains in realtime.

Finally, the implementation of BIAS X’s Agentic AI deserves recognition for its ease of use and high quality. Users with experience in prompt creation, sound engineering, and music production will be able to extract the best results when using this feature because their familiarity with the relevant terminology will enable them to communicate their ideas clearly. That said, Positive Grid has taken commendable steps to ensure that the AI understands the use of natural language, thus ensuring that people of all experience levels can yield creative and functional processing chains.

Newcomers to BIAS X may find the following list of quick tips useful when acquainting themselves with the plugin:

1. Re-ordering effects can radically alter the final output. For example, boosting/cutting the frequencies of an analog-modelled equaliser before a distortion pedal is a fantastic way to sculpt and automate the harmonic content of a signal.
2. Break convention by applying BIAS X to instruments besides guitar and bass. Re-amping Keys, Synths, Leads, Drums, Vocals, and orchestral instruments is highly effective for creative sound design and mixing purposes.
3. Enhance and create stereo width. Running mono signals through the Splitter and experimenting with different effect combinations in the parallel processing chains creates sonic complexity and a wider stereo image.
4. Repeat effects. Overloading the signal chain with the same effect can yield wild results. Remember to place a limiter at the end of the chain to protect your speakers and your ears!
5. Creative prompting. When conversing with the AI, describe your desired tone using language that isn’t commonly associated with music and audio terminology. The final output is often surprising and highly usable.

Conclusion

There can be no denying that Positive Grid has done an exceptional job in bringing BIAS X into the modern era. The app is thoughtfully designed, streamlined, and intuitive, with a host of fantastic processing modules and an innovative implementation of AI that will resonate with many users. Indeed, the quality on display is evident throughout every component and aspect of the plugin.

However, one can’t help but feel that choosing not to upgrade the pre-existing architecture was a missed opportunity. No doubt, Positive Grid has their reasons, but the deep customisation and tight integration of their early product range showed unique signs of promise that never maximised the potential on offer. It’s a shame that more couldn’t be done to reconcile the previous framework with the new direction because products such as BIAS Amp and BIAS Pedal demonstrated innovations that would clearly benefit from Positive Grid’s advancements in AI. As a result, some long-term users may feel their trust has been ruptured, and it may take some convincing on Positive Grid’s behalf to prove they are committed to the long-term support and development of their current catalogue. Should this be the case, the future is bright for BIAS X, which is in a strong position to capitalise on the rapidly evolving landscape of AI technology.

Technical Info

1. Simple download, installation, and authentication process. A Positive Grid user account is required.
2. Mac & PC are both supported: Standalone, VST3, AU, and AAX.
3. Positive Grid provides an online manual and a series of YouTube tutorials to help users get started with the software.
4. CPU usage is light and well optimised.

Disclaimer: This review was conducted on a MacBook Pro M4 Pro with 48 GB RAM and 1 TB SSD (macOS Sequoia 15.7.4). User experience with the reviewed software may vary with different technical specifications.

Alternatives

1. AmpliTube (IK Multimedia)
2. TH-U (Overloud)
3. Paradise Guitar Studio (Universal Audio)
4. Amp Room (Softube)
5. Genome Suite (Two Notes)
6. AmpHub and ToneHub (STL Tones)
7. Guitar Rig (Native Instruments)
8. Amplifikation 360 Bundle (Kuassa)
9. All Amplifier Bundle (Nembrini Audio)
10. Archetype Series (Neural DSP)
11. Axiom (Blue Cat Audio)
12. Helix Native (Line6)
13. Revalver (HeadRush)

BIAS X is available at the Positive Grid store for $149 USD. A free 14-day trial version can be downloaded to give it a try.

Josh Turvey is a musician, producer and an avid plugin enthusiast. He provides online, 1-2-1 tuition for guitar and music production for NoiseQuest.