Used on "Hymn for the Weekend", as mentioned by A Head Full of Dreams co-producer Rik Simpson in this Sound on Sound article.

It was very important to get the development and arrangement of the vocals right. Many of the 45 tracks are effect tracks. There’s only one lead vocal track each for the verses [LV Verse], for the bridge [LV Bridge], and the choruses [LV Chorus], and then Chris sang a number of bridge and chorus vocal overdubs. The main verse vocal has the Avid Channel Strip, which is taking out some low end, an SPL TwinTube, which adds some saturation, the UBK1 compressor adding more crunch, and the UAD Fairchild 670 and SSL E Channel. I don’t use a great deal of compression from each unit. I will just tickle it a little bit with each one, and each one adds a different characteristic. I could just add a whole load of compression from one plug–in, but like this it doesn’t sound over–compressed. The Pro–Q 2 is, again, a high–pass filter. In the sends there’s a Waves H–Delay that I recorded elsewhere, and sends to a main D–Verb and two QL Spaces aux tracks. I have different reverbs and delays for each part of the song so that the vocal sound evolves during the song.

“The main chorus lead vocal has the FabFilter Pro–Q 2 EQ, the Waves Rennaissance Vox, again the UBK1, two instances of the FabFilter Pro–DS de–esser, two instances of the UAD Pultec EQP–1A, and the FabFilter Pro–MB multi–band compressor. I like the FabFilter de–esser. I am still trying to find the ultimate de–esser, because it’s quite a hard thing to do right. I have two because one is doing high top sibilance, and the other lower stuff around 2kHz. The sends on chorus lead vocal go to aux tracks with the Waves H–Delay, the FXpansion Bloom with a lush, wide stereo delay, a small chamber from the QL Spaces plug–in, a mono delay from the UAD Echoplex, and several other delays. The sends to the delays are all automated independently, with different words getting different delays.

“One thing of note is that there also is a ‘Hope House M80’ vocal track, recorded when Chris was still using the Telefunken M80, and it’s mixed in very low. There’s also a lead-vocal double that has ‘251’ marked, indicating that Chris was also using that mic. But the main vocals were recorded using the Soyuz. There are two tracks marked ‘251 Melo Lead’ and ‘251 Melo Double’, again mixed in low. ‘Melo’ stands for Melodyne, and these tracks are raised two semitones. They were recorded in a different key for a different version of the song, and detuning them added a certain alien quality to these vocals which we really liked. At the bottom of the session are the Beyoncé vocal tracks, on which I mainly used the SSL E Channel strip, UBK1, L2, SoundToys Echo Boy, Avid ModDelay and the QL Space.”

Lady Gaga uses the Universal Audio UAD Fairchild 670 Tube Limiter Plug-In Collection, as confirmed by her engineer, who stated, "I like to use the UAD Fairchild 670 on the vocal bus, because it inflates the vocal. In 'Rain On Me' I used it to control Ariana's total vocal bus, and Gaga's vocal bus" (Soundonsound, Inside Track: Lady Gaga 'Rain On Me').

“The Universal Audio plug-ins are my bread and butter,” he says. “I use the UAD EMT 140 [Classic Plate Reverb], the Lexicon [224] Digital Reverb, and the Roland [RE-201] Space Echo. If drums or bass sound boring, UAD’s Fairchild 670 Compressor beefs stuff up and gives them character. Or the [Teletronix] LA2A plug-in on bass. Synths go straight to Pro Tools. Guitars and piano go to outboard effects like the hardware Space Echo, which I love for its unpredictability. I used a Manley Massive Passive EQ a lot too. The TubeTech CL-1B was the main vocal compressor. And I have a set of Lucas Limiting Amplifiers into a pair of Amtek Pultec PEQ-1A clones. That is a dummy-proof signal path. It’s hard to botch that.”

On the song “Don’t Lie,” I put the Fairchild 670 Compressor Plug-In on all the vocals, and on “Obvious Bicycle,” we had the Fairchild on lead vocals. I don’t know how else to describe it, but it just makes them sound buttery.

This has got to be my fav plugin

"Also, the Fairchild Tube Limiter Plug-In Collection is great because it is unique; none of the other compressors sound like it. On the Killers Day and Age, that was often a drum compressor, for either individual sounds or the entire kit. It suits Ronnie’s [the Killers’ drummer Ronnie Vannucci, Jr.] sound well. His kit is really more like one single sound source than a collection of multi-micing drums."

The main verse vocal has the Avid Channel Strip, which is taking out some low end, an SPL TwinTube, which adds some saturation, the UBK1 compressor adding more crunch, and the UAD Fairchild 670 and SSL E Channel.

Night session. #polefolder #uad #fairchild #mixsession

Used on Bocelli's vocals for "Fall On You", as mentioned by sound engineer Justin Cortelyou in this February 2019 Sound on Sound interview. An image of the settings can be found here.

"There are five vocal tracks because Andrea and Matteo sang some doubles, and also when we were in Nashville, some production decisions were taken about where to use Andrea's and where to use Matteo's vocals. Matteo re-sang the first chorus, which is the third track. We used slightly different EQ than on the previous take. The vocal chains we used on the two of them are different from any other vocal chain I have done! Andrea's vocal chain starts with the Massenburg Designworks EQ, with just a low cut and adding some high end. Next is the Eiosis e2 de-esser, cutting around 6kHz; the UAD Fairchild 670, not doing very much, only compressing in some hot spots; the Manley Massive Passive EQ boosting some high end; and the Maag EQ2, doing a sub low cut and adding some more air."

Jason van Wyk shared a photo on Facebook showcasing his use of the Universal Audio UAD Fairchild 670 Tube Limiter Plug-In Collection.