Purple Audio MC77 Plugin Review

Purple Audio MC77 Plugin
Purple Audio MC77 Plugin

When the UREI 1176 was no longer in production, Purple Audio stepped in to fill the void by making replicas of the world’s most famous FET compressor. Plugin Alliance has released a software version, allowing us to do a Purple Audio MC77 plugin review. The controls are essentially the same as the the 1176, so you’ll feel right at home if you gave an 1176 emulation already.

The Interface

Rotate the Input knob to the right to increase the Threshold and Gain Reduction. While the MC77 (and 1176) are easy for beginners in the sense that there are fewer knobs, it can also be confusing in not only the layout but the combination of this feature. Threshold is when the compression “kicks in” or starts compressing. Gain reduction is “how much” to reduce the sound or gain.

Once nice addition is the Link button. When engaged, the Output is reduced for you as the Input is raised. While this can be a nice feature, it can also be an annoying feature, so don’t feel bad disengaging it.

The Output knob can be treated as makeup gain. In an ideal situation, you would want to try and set this to match the track volume with the unit bypassed. Basically you want to toggle the plugin on and off, and adjust the output until they have the same loudness.

The Attack range is between 20 microseconds and 800 microseconds. Note the oddity of the knobs being backwards (another problem for beginners.) All the way to the right, “7” is the lower number of 20 microseconds, and all the way to the left is the higher number. When in the OFF position, Gain Reduction is bypassed. This could be useful to add distortion to the signal from unit without compression.

Release is between 50 milliseconds and 1.1 second. As with attack, all the way to the right is the lower number, and left is the higher number. The release time is how long it takes for the signal to get back from it’s peak compression to 63% of the original signal.

Key-In allows for Sidechain compression. If you use the UAD 1176, and are wondering why you would need this plugin, well here’s a pretty good selling point. If you aren’t familiar with the term, Sidechain compression will allow you to route one track (typically a kick drum) into the compressor to throttle the threshold. Rather than rely on the threshold level of the entire track, the sidechain will open and release the compressor, which can create some awesome pumping effects (or horrible pumping effects.) Originally it was used to help competing instruments to be heard.

The SC-Link button enables the stereo link for the sidechain. So if only the right channel is getting a sidechain signal, both the left and right will be compressed.

The radio buttons affect the ratio, which are 4:1, 8:1, 12:1 and 20:1. Use the hold button to select more than 1 button. The 1176 had a “British Mode” where you could push all 4 buttons in. The MC77 does one better and lets you push in combinations of buttons if the Hold button is down.

The Meter will show the amount of Gain Reduction if set to GR (depressed) otherwise it’ll be the signal level of the input or output at +4dB.

Brainworx gives you some nice extras that the original didn’t have. First off, Mid/Side mode is basically standard on everything they do, this seems like a compulsion for them 😉 When engaged, the top unit will do the mid and the bottom unit will do the side processing. The headroom will allow you to adjust the gain level of the plugin, which can be adjusted like a guitar amp to increase clean compression or cause “breakup” (or in this case “color”) at much lower levels.

The Parameter Link can be used to link the knobs on both units so that you can set the attack and release to the same amounts.

One of the cooler features added is the TMT functionality. No two analog units are the same due to the variances is components. This tries to emulate that by making believe you have 20 different units on 20 different tracks, not the same unit on 20 different tracks. Select a different “channel” and you’ll get a slightly different response.

The Mono Maker is a good way to check for phasing issues in your final mix. You can also use it as a cutoff, where anything below that frequency (bass) is converted to mono. Almost like a poor man’s Mid/Side. The parallel mix allows you to treat it like parallel compression where you can mix in how much of the compression effect that you want.

Purple Audio MC77 Plugin Sound Examples

So how does the Purple Audio MC77 plugin sound? I was dying to know how it compared to the Universal Audio 1176. I figured a Piano track would be a good test, so I pulled up an instance of each, and matched their inputs to act as a leveling compressor, meaning I set the Attack all the way up and Release all the way down, and gave them the lowest ratio possible, 4:1.

Purple Audio Leveling
Purple Audio Leveling
UAD 1176 Leveling
UAD 1176 Leveling
Purple Audio Piano
UAD Piano

Wow! Why is the UAD so much quieter? The Purple Audio is only trimming about 1/2db of gain, but the 1176 is hitting 20db. I had to turn the Input to almost 48 to get the 1176 to just trim 1/2db of gain and then raise the Output to match the loudness of the Purple. This is a good example of matching by eye and not matching by ear.

1176 matched by ear

Now they sound much closer and you can compare the difference. To my ears the Purple hits a bit more harder or compresses a bit too much. It sounds less natural on the piano attacks, but this could be perfect for dance music!

You may be wondering why I didn’t adjust the headroom knob, after all that is a nice bonus that brainworx gives you. That is another option, and I actually did do that. If I crank the headroom all the way down to -12 db, it starts to sound closer to the 1176, but only seems to get half way there. It is still louder and only gets down to -10db, while the 1176 goes to -20db and is not as loud.

Let’s just try the Purple Audio MC77 on a few different tracks and build a mix. This is a pluck chord progression. Notice how the MC77 can almost give it a reverb effect.

Purple Audio
Purple Audio
Pluck with No Compression
Pluck with Purple Audio

Now for the Drum Track. I’m going to do Parallel Processing, so I set the mix to 50% to blend in the compressed with the original signal. I am also setting MonoMaker just below 200HZ, as the kick is very prominent in the 50-100 Hz range. I want to accent the Kick and separate it from the snare(claps) and cymbals so I’ll turn on Mid/Side.

Purple Audio on Drums
Purple Audio on Drums

I tried to tune the mid to get the Kick pumping a bit more and if you listen to the claps, notice how they are a bit “wetter” than before.

Drums – Dry Signal
Drums – Purple Audio Signal

Next I’ll add in a little bass. I’m going to use the Monomaker to cutoff around 200Hz, and do Mid/Side. This way I can get a little more top end sound separated out so you can hear the bass on smaller speakers

Purple Audio on Bass
Purple Audio on Bass
Bass – Dry
Bass with Purple Audio

Let’s add in a Lead track and add in some sidechain. Ordinarily you’d probably want to sidechain with your kick, but since I put the drums all on one track, it doesn’t work well as a sidechain source. Instead I’ll sidechain with the Pluck Chords. This gives an almost gated type effect.

Purple Audio MC77 Plugin Sidechained
Purple Audio MC77 Plugin Sidechained
Lead – Dry
Lead – Purple Audio Sidechain
Here’s all the tracks together with no Purple Audio
Here’s all the tracks together with Purple Audio
Pruple on the MixBus.
Pruple on the MixBus.
With Purple Audio on Mixbus

I think that’s just too much compression! Perhaps different types of compression would be better, mix and match.

Final Thoughts

I think this is a nice FET 1176 comparable compressor and would definitely recommend it as a “fast” compressor on individual tracks. The mid/side is nice, and while it could be used on the mix bus, I would only do that if you use VCAs and Optos on the individual tracks. Don’t paint all you tracks in various shades of purple! Also, I don’t ever remember the UAD 1176 putting out distortion like this unit, so that could be good or bad depending on your needs.

If you don’t have a FET (1176) already, then I highly recommend this. If you do, then this might be a nice secondary option since it does seem to “run hotter” than the UAD version, and you get options to adjust headroom. The Monomaker is really useful as well. I do wish the Sidechain Filter had a Low Pass option and not just High Pass.

Check out our article on the Best Plugin Alliance plugins.

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Purple Audio MC77 Plugin
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