Replacing 12AU7 tubes in a Prima Luna Dialogue integrated amp


Bought the until about 2-3 years ago, as the core of a new system (Dynaudio Excite 34X speakers, Rega 8 w/ Apheta 2 cartridge, Rega Aria phono amp, Oppo BDP-105D for CDs plus video).

Very happy with the system.

One of the 12AU7's crapped out, so buying a new set.  Tried pulling out the bad one, and its really, really tight in the socket.  Never swapped these out before, not sure if the just pull up, or have some cam lock to hold them in. Afraid to force it, possibly break something on the socket, it sure seems very very snug.

Sound normal?  Just keep pulling up until it moves, or ? 

Any tips, tricks or info appreciated.  (and yes, I am using the gloves PL provided for all handling of amp items.)

Richard
dalorzof
Yes research is good but only you know what your ears like. I didn't care for the KT120's at all.  The 120's had too much glare or upper midrange energy for my tastes. Maybe not your tastes however.  I had no idea you already had KT88's in the amp as it usually comes stock with EL34.  Oh wait I just noticed you have the Dialogue and not the Dialogue Premium so that explains it.  So if you like the KT88 sound then what are you hoping to achieve or want to achieve? Would you like more warmth or maybe more detail?  Mullards will give you warmth and Cifte some detail and openness without any harshness. 
Before making any decisions I would call Upscale Audio and speak with Kevin or Jarod. Trust me he knows better than anyone PrimaLuna and tubes. Also look at the reviews on his website and that will also help and give you some insight. 
Was thinking they may bring a bit more depth to the mix, maybe a minor enhancement/separation to the midrange.  Not that the KT88's sound "bad", Just figure after 2 years maybe try something new.
And unfortunately Upscale Audio won't deal with International customers, I live in Australia....
Try Andy Bauman of Vintage Tube Services. There is nobody on the planet that knows tubes better than him. He tests and auditions every type of tube imaginable. If a tube doesn't meet his specs, he throws it in the garbage.