Tube Rolling

Hi Guys, I am going to be tube rolling very soon with my Primaluna Evo 300 Pre-amp &  Primaluna Evo 400 Power amp, Has anyone tried the new Brimar CV4003 / 12AU7 / 6189 for the gain tubes and the TAD KT88’s- STR Redbase for the power tubes ?

Many Thanks


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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 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.  

In terms of sound and texture.  Since I also have a PL Dialogue Premium.  What combo of Gain (center two) tubes and power tube combo would give you a taste of 300b goodness?

I am using some of Upscale's "Kevin's stash" Gold Lion 12AU7's and they sound great with 0 noise. They have a warmer sound than some of the others. Over the years, I have probably purchased @20 tubes from them. I've had very good experiences buying tubes from them. Same with Brent Jesse. In case you're interested I have a set of 4 reissued Mullard KT88's in my stash that I bought from Upscale and never used. If you end up trying out those Brimar 12AU7's, I'd be interested in your feedback. 

  Veerossi. What power tubes are you using with the Gold Lion 12au7s.  Which Primaluna do you have and would you say the sound is close to a SET or maybe even a 300b amp?

The NOS Brimar CV4003 has a moderate amount of warmth with extension up top and in the bass. Not as warm as Mullard, but is more detailed. I’ve used them in preamp gain stages and also in my amps.

Brent Jesse is a great dealer, but the CV4003s from Upscale are low noise and have lasted for years. Just so there's no confusion with other tubes, these have box-plates.

+1 Brent Jessee

Great selection of tubes, extremely knowledgeable, and will give an honest with confidence

Brent Jesse’s site is a fantastic resource of information.  When you want a little info on a tube’s characteristic sound it’s there. He himself has always been helpful to me in finding uncommon tubes that he didn’t even know existed.  
whenever somebody asks me what a certain tube sounds like I tell them to look up his site.  

Brent Jesse is the best! And yes I have used the Brimar NOS CV4003 tubes in my Primaluna and its a nice upgrade.  

I also have the PL preamp and amps.  Tube rolling has been a lot of fun.  As many said it’s worth it (and easiest to get an answer your question) by experimenting.  That said, I found the best place to put these 12AU7s is in the preamp (4 middle spaces).  The power tubes for the amps also make a noticeable difference.  I’ve tried just about everything else except the KT88s.  After experimenting with many, many different 12AU7s (in both the preamp and amp, and in all the spots - not just the center) I’ve found that there is a synergy with some tubes and the rest of your system.  I have a brighter system so the NOS Mullards and Brimars in the preamp are a nice fit.  For the amps the gain tubes I use the mil-spec GE tubes available on Upscale’s website.  I find they’re just neutral and get out of the way to allow the rest of the tubes to do their thing.  Most of my NOS tubes come from Brent Jesse, and as so many others have mentioned, his service is a tremendous opportunity for those of us in the hobby to get great tubes and advice at a great price.  
    Overall I’ll repeat the synergy thing and recommendation for experimenting in your system to find it.  Also, one thing I’ve found in my experimenting is the NOS 12AU7s are a big upgrade over modern production and definitely worth buying.  Brent Jesse has GEs available for cheaper than new production and they are so much better.  I don’t care for the Primaluna 12AU7s and have tried other new production tubes.  In contrast however, I find the stock EL34s to be excellent.  Lastly, be sure to listen to any new tubes for several weeks.  Don’t rush to judgement on them, they need to burn in.