Tube Rolling

I currently use the PrimaLuna Evo 300 power amp in my main system. I’m not aware of any reissue Brimar CV4003 so I assume you’re talking about the NOS variety from the likes of Upscale Audio. I have a pair of those, and while I have had them in my Evo300, I primarily use them in my tubed headphone amp where they excel. The Brimar CV4003 is a nice tube, but I’m just as thrilled with my Siemens silver plates, and an oddball pair of Blackburn plant Sonotones that are a complete 180 degrees from any other Mullard I’ve heard. 

Tube swapping is just one of those things you have to experiment with and figure out for yourself within your system. I’ve not used the TAD tubes, but have used the Gold Lion KT-88s with success in addition to the TS KT-150 which sound great, but in my experience has terrible quality control and thus longevity is an issue. Also currently loving the Gold Lion KT-66 in the evo. Price does not equal performance when it comes to tubes in my opinion.

Just remember the 2 innermost on both are what will have most impact.

Go to the Upscaleaudio.com site

 Plenty of PL user reviews on most popular tubes. I remember when those  were 1/4 the  current price!

The KT88'S should sound like... KT88's! Hopefully you'll prefer them over the EL34.

8 of them is a  pricey experiment.

I rolled the tubes in my PrimaLuna Integrated. Biggest impact was moving to KT-150’s.  I believe took the sound to the next level.  Also moved to NOS 4003’s and no way as an improvement as the 150’s.  I would start there.  

I used those tubes from Upscale in my Rogue ST-100, I really liked them and would swap with some Telefunken's, they both gave a nice contrast and kept things interesting. I thought the Brimars had a really nice tone and the telefunkens were a little more dynamic. On the Rogue, I believe these tube were the phase inverters, Rogue told me the phase inverter tubes had the biggest impact on the sound in their amp. For what that's worth.

You might also want to reach out to Brent Jesse.  He is more than happy to share his experience and opinion on which tubes to use in what equipment to achieve the sound / change you are  pursuing.