Preamp Tubes for a 5150

[darkerknight]

Hi there,

It is time to change the tubes in my 5150 script logo head.
For the power tubes I have a matched quad Ruby 6l6GCMSTR
I have this tubes available for the preamp:
1 tungsol, 1 Sovtek 12ax7LPS, 2 Electro Harmonix, 2 Chinese no brand (I think it´s sino), 1 Sylvania 12ax7WA

What is the best preamp combination? What should I put in V1, V2, V3, V4, V5?

Thanks in advance for all the comments and advice.

[toejam]

What's wrong with your preamp tubes? Unlike power tubes, preamp tubes hardly ever go bad and don't really need to be changed.

[darkerknight]

What's wrong with your preamp tubes? Unlike power tubes, preamp tubes hardly ever go bad and don't really need to be changed.

Nothing it´s wrong with the preamp tubes, it´s just that I need to change the power tubes, because I noticed some volume drops, and the amp has the same tubes since I bought it (and it was used gear) and I think I could improve the sound by upgrading the preamp tubes.
The preamp stock tubes are chinese (I guess), because they don´t have any brand.

[jgcable]

Buy a set from Ebay or Eurotubes. I ran a matched quad of Sovtek 6L6's and various 12Ax7A's in mine. Volume drops are most likely power tubes but I agree.. change them all if they are original. Just make sure you get a matched quad of power tubes.