The Metric Halo ULN-8 MkIV is an 8x10 USB-C audio interface with world-class AD/DA Conversion, ULN-R mic preamps and powerful DSP performance.

The Metric Halo ULN-8 MkIV improves greatly on its predecessor thanks to a completely redesigned board and FGPA replacing SHARC processors, dramatically increasing the DSP power and memory available.

World-class AD/DA conversion

The ULN-8 boasts excellent mastering-grade audio conversion, carefully revealing every detail of the original analogue source, allowing you to hear the position of your microphones, tape decks or classic analogue gear.

Both A/D and D/A converters are DC-coupled to the analogue I/O stages and provide very low phase distortion. The D/A stage features no low-frequency filter and can be used to generate CV signals to integrate with CV-powered modular synthesizers. On the other hand, the A/D inputs include a super low-frequency DC blocking filter that calibrates the input path and removes DC offset, preventing them from capturing DC CV signals. This can be circumvented with an Edgebus Card, which can add ADAT to drive third-party CV converters such as the Expert Sleepers ES-3. 

ULN-R Boutique Preamp

Eight channels of ULN-R mic preamps grace the audio interface, delivering pristine, low-distortion sound free from any artefacts. Each preamp provides an impressive 90dB of digitally controlled analogue gain which can be precisely recalled thanks to its ultra-precise 0.5dB steps. Furthermore, each input provides its own switchable P48 phantom power.

To complement the pristine nature of the preamp, Metric Halo have included an insertable Character Component Modelling Processing, which adds character from subtle wire with gain preamp to thick and rich tube mic preamps. 

The preamp supports input levels of up to +20dBu, removing the need for pads that affect the sound's fidelity. High SPL with sensitive microphones are not a problem for these preamps nor are low SPL with Ribbon microphones or low output dynamics.

In all cases, the input noise is extremely low with an EIN of -130.5dBu at 60dB of gain, ensuring the best performance possible.

Thanks to the high input levels of +20dBu, the inputs can easily be used as line-in, which could be combined to the line-in inputs to provide an additional 8 selectable analogue inputs as external sources.

The input path also includes integrated analogue Send (pre-A/D converter), allowing the units to be used as remote analogue pres. A Send/Return mode lets you add additional outboard before the A/D stage, such as EQ and compression. Another use would be to send the pre-amplified signal to a backup recording or mixing system, for example, when recording live performances.

Powerful DSP performance

The ULN-8 MkIV comes with Metric Halo's 3D digital signal processing engine, which offers a powerful mixing engine capable of mixing 128 inputs and 64 busses and an extensive audio router. The custom mix engine is much more powerful than the previous generation, with an equivalent DSP power of 30 SHARC DSPs.

The 3D architecture also includes programmable DSP, which supports DSP processing plug-ins which can be used as an insert in the mixer or for the output processing of the Monitor Controller. Over 100 plug-ins are available to use for low-latency monitoring.

The 3D system can improve each unit's performance by routing and sharing the load between multiple units attached via the MHLink, creating a truly unified system. It means that as the requirements increase, the system works as one system, simply adding channels up to 128 inputs and outputs.

Expandable with EdgeBus Cards

In addition to the ability to add additional interfaces, each interface includes an EdgeBus card slot which lets you add a module to add additional I/O.

The available modules include:

• AES/SPDIF EdgeCard (4 in/4 out)
• DB-25 AES EdgeCard (8 in/8 out)
• SPDIF + MIDI EdgeCard (2 in/2 out + MIDI I/O)
• SPDIF + 2x ADAT EdgeCard (18 in/18 out)
• 2x SPDIF + 2x ADAT EdgeCard (20 in/20 out)
• 4x ADAT EdgeCard (32 in/32 out)
• 2x MADI Optical EdgeCard (128 in/128 out)
• 1x MADI Optical + 1x MADI Copper EdgeCard (128 in/128 out)
• 4x MADI Copper EdgeCard (256 in/256 out)