Troy Van Leeuwen

At 1:11 in the video he says he uses this amp live as a dry amp in combination with his Vox and the Fender as wet amps.

Troy plays and talks about his Vox AC50CPH Head Amp, there is no proof that he plays this any time apart from just the occasional jam but it seems that Vox gave him this Amp in exchange for a bit of publicity. This video is posted by Vox Amps on Youtube.

This blog shows an interview with Troy about his team on the Post Pop Depression tour, and shows the new Echopark vibramatic 23 head amp.

"Troy getting a taste of his new 50 watt non master Narb Amplifier.."

Used on Gone is Gone, Echolocation and Villains, as stated in this October 26, 2017 AudioTechnology interview and this September 12, 2018 The Gear Page post by user Navyjon21.

AudioTechnology, October 26, 2017, "Too Close for Comfort: In the Studio with Queens of the Stone Age"

On the amp side, van Leeuwen relied on a two amp system. He used his Peavey solid state head for anything that was quick with a lot of attack. The other amp he used was an EchoPark Vibramatic 4T5 made by Gabriel Currie. “It’s a perfect mix of a ’60s Bassman and a ’60s Super Reverb with a little Vox,” he explained. “It’s very open. The head itself is small and he makes these cabinets with one 12-inch and two 10-inches in them, so I had the option of either speaker. I just love those speakers and cabinet, so I was using them most of the time.”

The Gear Page, "Echopark 4T5......anyone?", Navyjohns21, comment #8, September 12, 2018

I actually own the very first production model of the 4t5 which Gabe just told me is no longer being made. The amp was loaned to Troy Van Leeuwen of Queens of the Stone Age to record his side project gone is gone before it reached my hands. (...) If you are interested in what the amp sounds like in a live setting here is a link on youtube from Queens of the Stone Age live in Rio from 2015. Troy Van Leeuwen is exclusively using the 4t5.

https://www.youtube.com/watch?v=CSI3jWB6468

In the video "Queens of the Stone Age Rig Rundown with Troy Van Leeuwen" by Premier Guitar, at the 24:46 mark, Troy Van Leeuwen's live rig setup includes a pair of GMi 33F6 amplifiers.