There are a number of elements that go into creating a professional and polished final mix, but one of the true essentials is the last thing that the mix sees: the stereo buss compressor. So what makes Manley’s Variable Mu stand out among the many stereo buss compressors out there? Three words: tubes, punch, and glue.

Manley’s Variable Mu is an all-tube stereo limiter/compressor that utilizes the re-biasing of vacuum tubes to achieve compression in the same manner as the renowned Fairchild 670. This distinctive system of compression puts this unit in a class of its own sonically, which is perhaps why it’s found in countless mixing and mastering studios around the world.

Manley offers a number of modifications and versions of the Vari-Mu, and the unit I own is the Mastering Version. It comes stock with detented knobs and a high-pass side-chain filter, both features that I couldn’t live without. The rotary knobs are beneficial for a number of reasons: they are slightly higher fidelity, they allow you to match settings accurately on each side for stereo material, and they give you the ability to precisely recall settings with ease. The high-pass side-chain filter allows frequencies below 100Hz to pass through the compressor unprocessed, so that the bass isn’t driving the compression on the whole mix; this translates to punchier mixes.

A key element to consider when utilizing a stereo buss compressor is that the mix will change when the compressor is engaged. I always mix with the compressor in the signal chain so that I’m hearing and balancing what will become the final mix. This is one of the main reasons that it’s advantageous to utilize a stereo buss compressor in your signal chain while mixing, rather than holding off for the mastering stage.

In terms of use, I run the Vari-Mu in compression mode (1.5:1) with the attack speed at the fastest setting (25 ms) and recovery at MF (0.4 sec) with the threshold set for around 2-4dB of gain reduction and the output with a slight increase in level when compared to the unit bypassed. I almost always have the high-pass side-chain filter engaged and run the unit in SEP mode (as opposed to LINK), which seems to give a more balanced stereo image.

I strongly believe in the value of investing in one’s personal studio, as you only get out what you put into it, and in time, those investments will pay off. There are certainly more affordable stereo buss compressors available, many of which are great in their own ways, but I have to say that the Manley Variable Mu Mastering Version Stereo Limiter/Compressor is truly top-of-the-line, and has proven well beyond its worth in investment.

I hope this entry helps you understand the importance of stereo buss compression in the mixing process and how the Manley Vari-Mu is an extraordinary tool for creating more professional and polished final mixes. If you want to learn more about the Manley Variable Mu Limiter/Compressor, please visit Manley’s website at http://www.manley.com/mslc.php

Have any questions or comments? Feel free to leave them below.

Until next time,
Val Garay





Nigel BrownVariable Mu