In an interview with Vintage Guitar® magazine, Steve Miller discusses his use of the Fender Concert Blackface Combo Amplifier, specifically mentioning its 1959 brown tolex version.

For sale from Nils Lofgren is an absolute classic: A Brownface Fender Concert Amp from the early '60s. The combo has undergone a number of mods including: an early recap on a few of the key caps, four new 10" Weber Vintage Series speakers, new tubes, and a custom route on the side with what looks to be a mount for a fan (fan not present). The amp has plenty of where wear throughout and is missing the handle, as well as the volume, treble, speed, and intensity knobs. You can tell Nils loved this one and likely toured with it heavily.

On Burton's website, it is mentioned that he used Fender Concert. The Fender Concert Blackface is pictured as an amp he used, so we can assume he used Fender Concert Blackface.

In this Youtube video John plays into his 1964 Fender amp and talks about its features and qualities and what he likes about it.

Jim Roth is associated with a Fender Concert Blackface Combo Amplifier, as highlighted in an Instagram post by jermsfuzz. The post describes this amplifier as a rare late '63 model with distinctive features, such as black Oxford speakers and unusual brown Fender bell caps, and notes its construction on a Bandmaster/Showman chassis.

Mentioned in this February 22, 2016 Ultimate Guitar interview.

What type of guitar/amp did you use on "War Path" and other really early tracks?

It was still the Les Paul, Jr. then and most likely it was a Fender Concert amp with four 10" speakers.

(...) There were many more projects and these all - or a lot of them - pre-date 1965 when you got the Jazzmaster. So what kind of guitar/amp were you using for these projects?

I think all of them were the Les Paul, Jr. and the Fender Concert amp.

Did you ever use any kind of pedal at all for these sessions?

Sheesh, I don't think I was even into the wah wah yet.

Did all the effects come from the amp (tremolo, reverb, et al)?

Yes, plus studio devices.

Was your first film project "Skaterdater"? What was that like recording music for an entire film?

My first film for sure. It was a four-hour, no overdub session with a great bunch of musicians: Arrows drummer Larry Brown, Al Casey on rhythm, Jim Horn on sax and flute, and Larry Knechtel on piano. I'm not sure. It might've been Don Randi. Also, as it was with all the films, we never played to scenes in the movie.

For all these various projects, were you using the Jazzmaster and Concert amp?

That's true although many times I overdubbed my leads through the mixing board in the studio.

Had you given any thought at all to more distorted/fuzz guitar sounds at this point?

I only used the fuzz on the main "Skaterdater" theme plus my version of "Scratchy" and some non-leads on a couple of other tunes on the "Apache '65" album. The fuzz didn't take over my life until "The Wild Angels."

(...) In 1966, you did the music for "The Wild Angels" film and the "Blues Theme" was written. Had you been thinking about creating a more distorted/fuzz-driven guitar sound?

I was definitely thinking along those lines because of it being a biker film.

Was it a conscious thing to get away from the clean, reverb-drenched surf guitar sound?

I wasn't a fan of the reverb and didn't think the word "surf" fit. But yes, I wanted to make a drastic change from my '63 to '65 sound.

Can you talk about those early days experimenting with fuzz sounds?

I was only using the Gibson Maestro but not doing much with distortion until the Mosrite Fuzzrite came along.

Did you try out different amps? Were you turning everything up to 10?

Just my Fender Concert and I only turned the amp up to 10 for "Blues Theme." We knew we wanted a powerful and gnarly sound and having the amp blast out like that was amazing plus it leaked into all the other microphones. By the way, it was recorded in mono.