Different Tubes and general purpose?

Wsrrsw 
I’ve perhaps underestimated my hours, but not by much.  On average i may get 6-8 hours a month, but with the current quarantine its maybe 4-5 hours a week.  
Room is large with 14ft ceiling.  Speakers are Harbeth HL5 plus.  Power seems fine and I do use a conditioner, contacts all fine to the. Eat of my knowledge.  All equipment is 3-4 years old. 

Hi gunners01

I have an amp that uses a similar tube compliment. This is what I have done. And it made a Significant Difference! 
Perhaps it can help you in your search towards refining your sound.
 
On the Line Magnetic Website:
https://www.line-magnetic.eu/en/products-line-magnetic-en/integrated-tube-amplifier-line-magnetic-en/lm-501ia-amplificateur-int%C3%A9gr%C3%A9-push-pull-kt120-2x100w-detail

They include this helpful  info:

Tubes Basics              Common Replacements

12AX7                         12AX7EH, ECC83, E83CC, CV4004, ECC803,                                          5751
12AU7                         ECC82, 12AU7EH, 5814, 6189, CV4003

6SN7                           6NP8, 6H8C, 6H8M, 6F8G, CV181, QB65,                                                  ECC32

As others have mentioned, I too have used Brent Jessee as a resource to educate myself on the differences - 

https://www.audiotubes.com/

For the 12AX7/AU7 - I have tried Telefunken, Mullards, Heath, Mazda and Siemens.

Currently I have been very pleased with.. 

2EA. 13D5 /12AU7 Brimar longplates and 1EA. E83CC Siemens 

This combination has the right amount of detail and musicality for me. Increased the depth of the soundstage, fleshed out details in midrange.

Although I find that the Telefunkens are the most detailed, they seem too focused on the upper end, and conversely the Mullards can be too sweet sounding and not capturing the same details in the midrange.

I do not use the 6SN7 Tube, but If I did, I would be inclined to look towards RCA, Westinghouse or GE.

On the Line Magnetic Website they state:

Tubes we choose are.... and Tung-sol KT150

The KT 150s are expensive so perhaps start off rolling the signal and driver tubes, and then move to the KT150s or see if LM would give you a break on a set of replacement KT150s.

Every bit counts, so replacing stock fuses and power chords do help.

I have been happy with Isoclean Audio Grade Fuses

https://www.vhaudio.com/isoclean-fuses.html

Power chords is subjective - cable company has a lending library

https://www.thecableco.com/lending-library

Best of Luck

Good find on the tube info.
TUBES
Input stage: 2x 12AX7
Rectifier: 1x 12AU7
Drivers: 2x 6SN7 (Electro Harmonix)
Power stage: 4x KT150 (Tung-sol)

The tubes that influence the sonics the most are the 12AX7 inputs. They are the preamp and the input gain to the amplifier. This gain stage has a high amount of voltage, thus the sonic signature of different tube brands will be most audible.  
The drivers will have a lesser effect on sound. Their job is to
take the input signal and split it into two identical signals, each 180 degrees out of phase with each other. These signals drive the output tubes. IMO, you can live with the stock 6SN7s for now.
Rolling rectifier tubes most definitely influences the sound.

You have very low hours on your amp. To increase the burnin process you can leave the amp powered up while you are home. Never leave a tube amp unattended.
You only need to have the amp turned on, no components, no music, but the amp must be connected to the speakers.

My amps can take many different output tubes....  that said , it sounds completely different based on the output tube.   The input tube also changes the character of the amps.    It was voiced using EL34 and even the different brands have their own sonic signature ...    currently using JJ EL34 and it is the best sounding of its type I've used.