Brimar vs Mullard cv4003/12AU7

I’ve used both as input tube and drivers in my power amp. I very much like the combination.
The Brimar has warmth with more depth and more extension at both ends. Tight bass. Mullard has the warmth but is more refined, realistic with soft highs. A Mullard in the right circuit can sound holographic.

I no longer use my trusty NOS Mullards (new amp, different tubes) but for me the best thing by far about those tubes was the flash at start-up. Sure, they sounded great, but it's that flash…oh yeah…uh huh...

I purchased my Brimars from Upscale after trading emails with them to get a thorough description of their sonics. They came in original NOS boxes with plastic pin protectors and are well built tubes.
There are at least 4 different types of Mullards with a different sonic signature, the cv4003 is the ruggedized version. Sweet, liquid mids like the Brimar, both have boxplates.

A Mullard in the right circuit can sound holographic.

Hello, Mullard Man here.  No comparison, (in the right circuit).  The Mullards are hard to beat.

I've not tried the Brimar's but immediately chose the Siemens E82cc/12au7 over two different Mullard's, including the CV4003.  I also preferred the Siemens over the Radiotechnique 12au7.

Call Andy at Vintage Tube Services and ask his opinion on the Brimars.

Old thread, but I’ve tried both in a rogue sphinx v2. For me, the mullard’s sounded better...more holographic. They both have good dynamic range and are quiet in my system, but after using the Brimars for a while, I switched back to the Mullards. I’m thinking it might be system dependent though

@bradbort , yes it's system dependent. I'll add that it's component dependent.
I used Mullard longplate square getters from the 1950's for years in a preamp. Also used a Mullard CV4004 as an input tube in my amp.
When I changed to a new amp, I needed more clarity and extension, and the Brimars were a better fit.

I preferred the Brimars on an Octave V80SE integrated.  They were nothing short of glorious.