Primaluna signal tube replacement

If the filament supply can handle extra current, and if the filament voltage is 12V (not 6V), then a great upgrade from the 12AU7 and its congeners is the 12FQ7.  Even as a cathode follower, the 12FQ7 can be heard to be an improvement on the 12AU7.

I would replace all the stock 12AU7s with NOS or UOS RCA or GE tubes. 

and you can sub in the 5814As which are electrically the same but are lower noise tubes. Have owned 7 of the PL amps. One of the biggest improvements I got was pulling all 6 of the input tubes and replacing with RCAs. They are not expensive either, tons and tons of 12AU7 and their variants were made. 

All great advice. Thanks.  Especially the “reseating” comment.  I think I’ll work the originals back into those slots and see what happens.  I tend to overlook the simple stuff sometimes.  I sure love this amp.  

Primaluna’s stock tubes in the outer positions are fine. I have been running vintage Amperex "Bugle Boys" in the gain positions with great results. On the power amp I run A-matched EL-34's from Sophia Electric - also outstanding.

I bought some of “Kevin’s stash” tubes for my Mac preamp mc phono stage.  They are so quiet, it’s scary. Well worth the money. 

I own a PL DiaLogue Premium Integrated that's about 7 years old. It's in daily use  2 to 4 hours per day.  Several months ago the a couple of the 12au7 tubes became noisy, and I decided to replace all six (6) of them.  I went with General Electric JAN stock from Upscale Audio - and opted for premium grade a/k/a "Kevin's Stash."  They've been wonderful - dead quiet. Not cheap but well worth the money, as far as I'm concerned.  

https://upscaleaudio.com/products/ge-12au7-6189w

"My spares were Primaluna and the noise vanished"

Sometimes, merely re seating the tube in the socket cures

noise. The suspect tube may still be good.

Hey thanks for that.  I swapped speaker cables and the scratchy moved with it.  My spares were Primaluna and the noise vanished.  So,, replace my spares now.  Voodoo

The 2 innermost (gain)are the slots to fuss with.

The other 4 slots arguably are fine with whatever brand you choose. Any  " SQ improvement" is subtle at best- more so than changing the 2 gain tubes.

2 years seems a little early to change out preamp tubes(other than an apparent fail), even with lots of use.

PL HP user here.