I wanted to add some additional thoughts on the Pendulum ES-8. I wrote a review after having it in my studio for a while. What I expected was a cleaner tube compressor that added a little character to a 2 bus mix. When it did not, I was a little disappointed with the unit though it was still a well made clean tube compressor.
2 years later I had the opportunity to check it out again, and this time I fell in love with it. The second time around I removed preconceived notions and just listened to what it did. I also had more experience in hearing other high end mastering compressors as well and had a deeper understanding. With the ES-8 or other cleaner compressors the mistake is to listen for what character, sparkle, or change in tone the compressor adds to the signal. As many clean compressors don't do that, what you do have to do is learn to listen only on how the mix affected? If you just focus on the signal, you hear how the ES-8 is able to reduce the peaks while staying out of the way. It has the ability to keep the sparkle, 3 dimensional sound you had after going through a nice bus compressor like a Portico or API. It allows you to clearly hear the reverb tails while at the same time reducing the peaks without being heard. When you learn to hear for this, a smile will come across your face. In addition, you are able to hear the subtle density it adds to the center of the mix. The ES-8 is a work of art. The Fairchild presets work really well, and you have the ability to reduce deeper without affecting the signal. It is similar to some high end solid state clean compressors you are aware of, but the tubes in it does add a slight smooth sound but it is gentle. When you want to just control the transients without changing the overall sound of your mix, the ES-8 will do it.
Many times mixes will need something to warm them up as they may be too clean. You may want to add some analog character. But when you get the sound you want as the recording stage, and you don't want to change the sound but just help it to gel, the ES-8 will do just that.
Here are two helpful threads to help you understand the compressor. The first is my review which shows the updated review 2 years later as well. The second thread has a comparison of the ES-8 to other compressors.
Pendulum ES-8 Vari Mu limiter
thermionic phoenix-manley vari-mu-pendulum ES-8 shootout