Mentioned by mixing engineer Michael Brauer as being used on "Violet Hill" in this Sound on Sound interview about the production of Viva la Vida & Death and All of His Friends.

Vocals: Waves Renaissance & Digidesign de–essers, AMS reverb, Zoom 1202, Lexicon PCM81, Watkins Copicat, Empirical Labs Distressor, Federal, Gates, Fairchild 666, EAR 660, Neve 1176 & Awa G7201 compressors

"I used two Renaissance de–essers on Chris's voice that were doing different things, and then a stock Digidesign de-esser. That was it for the plug–ins I added on this session. The Sonnox Oxford and the Eoisis were not out yet at the time.

"The analogue things I did on the lead vocal are really interesting. As I said, I initially mixed the songs on my own, because the band was in England re–recording some songs, so I knew I might have to recall each song. But on this song I pretty much nailed it, apart from that Chris wanted the vocals to be more exciting and different. In the end the vocal had some AMS non–linear reverb on it, while the main sound came from an old Zoom 1202 reverb and a Watkins Copicat delay, plus a special patch that I created in the PCM81, which is a much bigger reverb. So it's a combination of things, but you don't really notice them, all you notice is that Chris is in a very present, big room. When I had found that combination 'Violet Hill' really became a song, it really came alive, because his voice was able to fight through all the stuff that was going on and make it personable. There's no reverb on the rest of the track, which is another reason why the lead vocal sounds so huge: it's not fighting another bunch of reverbs. If you send everything to reverb, you don't hear it, but if you send only one thing to reverb, it'll be huge.

"For the main part of the song I had a Distressor on the insert of the lead vocal, and I sent this to another five compressors: the Federal, the Gates, the Fairchild 666, the Neve 1176 and another Distressor in Nuke mode. They're all coming back individually on the board, and it was a matter of blending those compressors. As usual in my way of working, the compressors are there to give attitude and tone, and don't necessarily compress. For the end bit of the song, where it's just Chris and the piano, I used the Awa G7201 limiter/compressor. It's an Australian compressor and it has an incredible air and presence. It's a unique sound that you can clearly hear at the end, as it's the only effect on the vocal on that point. Finally, the church group background vocals are sent to the same combination of reverbs as the main vocals. No other effects, no EQ. It means that all the vocals in the main section blend together."

From the live Mix with the Masters masterclass : Answering the question "What is your favourite studio gear ?" Xavier answers "Definately the Ear660, it's the ultimate weapon. We have like 4 of them. If the studio was burning, I would unscrew them out."

Mentioned in this February 12, 2015 article from the Vintage King website.

2015 was a remarkable year for Vintage King clients involved in the music industry, as we had over 30 artists, producers and engineers we work with nominated for Grammy awards. While we all know how secretive sonic creators can be about their work process, we asked a few of our favorite studio workhorses to divulge the secrets of their Grammy-nominated vocal chains.

While Chris Stapleton may be a new face for many music fans, producer Dave Cobb (Sturgill Simpson/Jason Isbell) and engineer Vance Powell (Jack White / JEFF the Brotherhood) are no strangers to creating amazing records. When deciding what gear to use during the recording of Stapleton's Grammy-nominated album, Traveller, Cobb asked Powell to select what would be used in the vocal chain.

The end results saw Vance opting to use a vintage U47 and running them through vintage Neve 1073 and an Esoteric Audio Research 660 for compression/limiting. The vocals were all cut live with the rest of the band playing in the same room at RCA Victor Studios. The only exceptions were two albums tracks that were recorded outside the front of The Castle studio, thus the sound of passing cars and crickets.

Mentioned by mixing engineer Michael Brauer as being used on "Violet Hill" in this Sound on Sound interview about the production of Viva la Vida & Death and All of His Friends.

Bass: EAR 660, Altec 436B, Dbx 160, Akai S612, Moog MKPE

"The bass was interesting. I had the same bass track coming back on two channels, and on one of them I had the EAR 660 compressor, going into an Altec 436B compressor, going into my Moog MKPE three–band parametric EQ, all going via the inserts. That channel was for the low end, giving the sound its fullness. On the other channel I had a Dbx 160, crushing heavily, with the bottom end taken out. That gave the bass its punch and mid-range. I also sent the basses to an Akai S612 sampler. A friend of mine turned me on to doing this. I don't use it as a sampler, but as a distortion device. If you put the Akai in microphone mode and you overload it, you get really nice warm distortion that you don't really notice, but it sounds good. If I want something more vicious than the Akai, I'll use the [Thermionic Culture] Culture Vulture instead, which I feel is one of the best pieces of equipment for adding some attitude. It's great for when tracks are recorded too cleanly. Finally the basses, like the drums, went through Bus B in my multi–bus compression setup, which consists of Distressors going into my Avalon E55 EQ."

In a photo taken in the control room at Tottenham House during the recording of Radiohead’s In Rainbows in September/October 2006, it is evident that music producer Nigel Godrich uses the Esoteric Audio Research EAR-660. This is confirmed by the image showing the EAR-660 in a rack alongside a blackface UREI 1176, three silverface 1176s (Rev H), and a Tube Tech CL1B. An Elektron MachineDrum is also visible on the piano bench, and an early-2000s Apple iMac can be seen in the control room.

In a video by MusicRadar Tech titled "Fred Falke In The Studio With Future Music," Fred Falke demonstrates how he uses the Esoteric Audio Research EAR-660 as part of his outboard gear setup to process audio tracks.

According to the "equipment list" found on Church Studios, owned by Epworth, one of the things listed is EAR 660.

"Let me shake the cobwebs out. On Sing the Sorrow I remember that we spent half a day trying different mics (15 or more), mic pre's and compressors. We finally settled on a Blue Bottle w/B-6 capsule - Chandler TG-2 mic pre - EAR 660 compressor. We would record in parts - singing parts, quiet singing and screaming parts. Dave does have an incredibly dynamic voice so it took a lot of riding of levels. On decemberunderground I changed up the chain a bit and on the new album I tweaked it again to suit his singing style." - Joe McGrath (recorded Davey Havok)

https://www.gearslutz.com/board/showpost.php?p=4295011&postcount=8&s=1dfbebf221826bb7b27355b339a88600

Philippe uses 2 E.A.R 660 on his mix bus

In the YouTube video titled "わーだーさんのスタジオ訪問記〜NK SOUND TOKYO編〜【ニラジ・カジャンチ Neeraj khajanchi】," composer Neeraj Khajanchi showcases his studio setup, featuring the Esoteric Audio Research EAR-660. This Fairchild-type valve limiter-compressor is renowned for its transparency and exceptional transient response, making it a preferred choice among audio professionals for its effective signal processing capabilities.