Universal Audio Manley Variable Mu Limiter Compressor Plug-In by Marando
In 2010, Universal Audio released the Manley Labs Massive Passive EQ plugin, an emulation of the famous hardware EQ with the same name. I remember it as if it was yesterday that I first launched the demo and started tweaking the virtual knobs. I could suddenly do boosts and cuts that sounded more musical than any other EQ plugin I had ever used before. The way it handled a complete mix and opened up the sound was stunning. For the first time it felt as if I was using an actual hardware EQ, instead of a plugin. It is from that moment that I have been waiting for Universal Audio to make an emulation of the famous Manley Labs Vari Mu Limiter Compressor. With the release of 7.11, the wait is finally over. The UAD Vari Mu is here, and I have spend a lot of hours with it to find out if it possesses that same magic as their Massive Passive plugin.
The most common types of hardware compression designs are FET (Field Effect Transistor), VCA (Voltage Controlled Amplifier), Opto and Variable Mu. Without going into detail, they all have their own way of controlling the amount of audio passing trough. Variable Mu is the only type of compression (I know of) that actually uses tubes for the compression, unlike many "tube compressors" that are Opto based compressors, and use a tube for the gain compensation. Variable Mu compression is said to be very musical, sweet and smooth sounding. For this review I have been using the UAD Manley Labs Vari Mu Limiter Compressor plugin in a lot of different scenario's, to find out strengths and weaknesses.
The developers of Universal Audio have had the help from Manley Labs to design this emulation of their famous hardware device. The GUI very closely resembles the actual hardware, with a lay-out that is pretty much a mirror between the controls for the left channel and right channel. Let's take a look at the most important controls of the Manley Vari Mu. There is a switch for the recovery speed, which can be set in five steps between slow and fast, being 8 seconds, 4 seconds, 0.6 second, 0.4 second and 0.2 second. Next to this control, we find a knob to set the output level, which can be used for example to compensate for any gain loss that might happen when the compressor is doing it's thing. In the top middle, there is a knob that handles the input gain for both channels. It is said that this is not just a simple clean gain knob, but it's also entirely modeled after the dual input knob from the hardware. At the bottom, we find a knob for each channels to set the threshold and a knob to set the attack time. The attack time can be freely adjusted between 25ms (fast) to 75ms (slow).
Not all controls you find on the plugin are found on the actual hardware device, one of them being the mix knob. This knob gives you easy access to parallel compression, by blending the dry signal with the wet signal. And while doing this, you don't have to worry about phase/timing issues between both signals. Other plugin enhancements are controls to link both channels and a headroom knob. The inclusion of the M/S mode, which is also available as a modification for the hardware unit, is also a very welcome feature!
An important piece of information with regards to Universal Audio plugins, is the amount of DSP power they require to run. Knowing that the Manley Massive Passive plugin takes a hefty 60% of one DSP in stereo @44.1khz, I was pleasantly surprised to see the Vari Mu only consumes 24% of one DSP in stereo at the same sample rate.
I have had the pleasure of listening to an hardware Manley Vari Mu a few times in the past during a mastering session and I remember the device as being a box that could transform a mix into a finished master. The way all the different instruments in the mix became one big happy family with just a few dB of gain reduction on the Vari Mu was like magic to me. It's for this reason I first started putting the UAD emulation in a mastering session I did a few weeks ago, to see if it could provide me with that "magic" I remember hearing with the hardware.
After a few minutes playing with the threshold, attack and release times and gain staging, a smile appeared on my face and it stayed there for the rest of the session. Unfortunately, I can not directly compare the plugin to the hardware, so I can't say if it is a spot on emulation or not, but what I can say is that it reminds me of my experience with the hardware and I believe I can hear the magic that made the hardware so much desirable to me. Just as with the hardware, it can really transform a mix into a finished master, by glueing all the different elements of the track together in a way that I have not achieved with any other compressor plugin. In this particular mastering session, it was almost as if I used it in M/S mode to make it more spacious sounding, but in reality I was using it in regular stereo mode with both channels completely linked. And while M/S mode can have a tendency to make the stereo image unnatural, in this case the subtle widening effect I witnessed sounded totally natural and desirable to me. I a direct comparison with some other great bus compressor plugins, I could not get the other compressors to give me a more pleasing way of compressing this particular mix. I might be biased, or effected by the so called "honeymoon" period, but I kept going back to the UAD Vari Mu as being the one I felt suited this song the best.
The next job for the UAD Vari Mu was compressing a male lead vocal. I spend a long time comparing different settings and I ended up with a fast attack/release, some pretty big boost with the dual input knob and the compressor mode set to limit, making the plugin show roughly 2 to 4 dB gain reduction on average, but on the occasional peaks, the meter easily showed more than 10dB of compression. Still, the result was a lead vocal that sounded very smooth and natural to me and I needed little EQ to make it sit perfectly in the mix. I can see myself using the Vari Mu plugin on vocals more often. Other compressor plugins I love on vocals are the UAD 1176 and LA-2A Collection and I believe the Vari Mu is a great addition.
So how does this new toy from Universal Audio behaves on other sources, like piano, guitar, bass or a complete drum buss for example? I tried it all and in every situation I could find a setting that I believed sounded good at least, but not necessarily better than my other favorite plugins for these particular tasks. During my experiments however, I found out that using a combination of the Vari Mu plugin, together with one of my other compressor plugins, often gave me very great results, results I somehow could not achieve without the Vari Mu. This strengthens my believe that the Universal Audio developers have truly modeled the entire signal path of the Manley hardware unit, so that simply adding the plugin already does something nice to the audio signal, even when there is no compression happening.
With the release of the UAD Manley Labs Variable Mu Limiter Compressor plugin, one of my wishes has come true. But, releasing this emulation is not enough, the plugin also has to sound incredible and have that magic the real hardware unmistakably has. In my opinion, it truly delivers. For me, this plugin is a true king when it comes to compressing a complete mix. But simply adding this plugin on a sound source and using the dual input knob to drive the signal (and the output knobs to compensate if necessary) is a trick I will be using a lot more in the future. For me, the UAD 7.11 release feels like an early Christmas gift!