Questions from a Tube Preamp newbie

I have a lot of the CV4003s from Upscale.  They used to be $35 each for the Platinum Grade.  These are the ones that I've had no problems with.  I've used them in DACs, preamps, phono stages, all over.

I also have several other types of Mullard 12AU7/equiv.

I'm a tube newbie like you and it looks like you're getting great recommendations specific to your preamp. When I got the tube rolling itch, I contacted Aric at Aric Audio directly and he recommended a specific set of tube brands and models; rectifier, voltage regulators, and 12ax7 signals, and I swapped them one at a time over a month period just to gauge the improvement. Collectively, they took the preamp to an entirely new/better level. His recommendation was based on his own personal experience rolling many different brands/models in the same unit he uses regularly in his own system. So sometimes asking the designer may be a good approach. Mine came with JJ 12ax7 signal tubes and apparently the Electro Harmonix Gold pins work best in this particular model. Total cost was $85 for 5 tubes. By the way, in my case, the overall difference after the swap was not subtle or just a matter of taste, etc. It just made the music sound better. I asked him why doesn't he sell them with these tubes and his response was I was the first person who contacted him for tube suggestions and secondly most people have a favorite brand/model in mind and just go ahead and roll tubes regardless of what comes with the unit so why put more expensive tubes in. By the way, he also gave me some recommendations for upgrading a small number of the capacitors to Audyn Copper to make it sound "crazy" good. That's my next plan.
Good luck and enjoy the music.

What was the problem with your Rogue preamp? If I remember correctly there was a lot of hiss, etc. What did Rogue do to it besides change tubes?

They told me that they repalced some Op-amps and added some grounding to the LED display

@aberyclark , there's no rule that says that all four tubes need to be the same type. When I owned a Perseus Magnum, I had 2 RCA Blackplates in the front Gain position, and Mullards as Cathode Followers. The RCA's provided open, dynamic sonics, while the Mullards provided warmth and classic tube bloom.

The best deal that I've come across is the Brimar CV4003 at Upscale. These are British tubes with warmth, but have more extension than Mullard at the top and low-end.

Picked up a pair of Telefunken 12au7's and a single 12ax7 from Andy Bouwman at Vintage Tube Services this past summer for my integrated amp. (not a Rouge)  Andy is extremely knowledgeable and fair in his pricing. He is a straight shooter and won't just sell you something for the sake of it. All of his tubes are tested before shipping and have a return policy.
Check him out at:http://vintagetubeservices.com/