In this article it states : "The main adjustment to his mixing routine has been an analogue summing setup that takes that task out of Ableton Live’s hands and adds a bit of colour to the stereo bus. He bought two 16-channel Lynx Aurora converters that feed a pair of passive 16-channel RMS216 Folcrom passive summing mixers. The sum of the 16 stereo channels hits a pair of Neve 1073DPA preamps first to “crunch the mix up” and make up gain, then an SPL Vitalizer, the one piece he’s had for a while and is “just like a glorified EQ that adds a bit of artificial valve quality.” The last thing strapped across the master bus is a Manley Vari- Mu compressor before it gets fed back into the DAW to print. The gear doesn’t see any use other than for mixing, so it allows Parker to leave it set up and return to any mix at will. “I’ve always loved mixing with Ableton,” said Parker. “But I love the sound of a mix being crunched together in analogue. I love the sound of a desk, but I hate not being able to recall any time I want. I flit between songs, sometimes every few minutes. It goes completely against my workflow to have to set up for one song by going around the room and setting EQ knobs on a desk and adjusting faders to how the mix was last time. It’s against how I’ve grown up working.” For the recording of Tame Impala's album Currents

In a Q&A, Wolfgang Gartner talks about his mastering process: "It’s extremely important to have a good mastering job, but how you choose to do it is down to personal taste. I decided to start mastering my own stuff last month and invested in some nice hardware to help do the job. My main tools now are a Crane Song STC-8 compressor and an SPL Tube Vitalizer, in addition to a pair of Empirical Labs Distressors with British Mode that occasionally work for mastering, but not always. Aside from that, I just throw a limiter on top and maybe EQ it a bit in Cubase, but overall I let the hardware do most of the work."

Original source here.

From his blog post on home mastering. "This thing can really make things shimmer. While it's capable of much more, I tend to use it to bring out high end clarity and energy when a track is a bit muddled - probably the only instance where I'm using a tool to combat a problem I couldn't or didn't solve in mic'ing or mixing. Usually first up in the chain."

In his reddit AMA, Doctor P say he uses the following

"instruments: massive kontakt battery nexus diva korg legacy collection minimoog processing: fabfilter pro q camel phat waves C1 waves SSL comp SPL tube tech izotope ozone wow i never realised how small the list of my plug ins would be"

Mixing engineer Jaycen Joshua includes the SPL Tube Vitalizer in his gear list, as detailed on his official website.

Can be seen throughout the video in the rack on the right of the screens