listening to it alot recently , and since and the tubes and caps are breaking in , the highs
have started getting “brighter”. Not bad but noticible and the bass though still tight and
nice sounding it is getting a bit louder more pronounced . ( It still sounds better than the
old Preamp ! ) Though I would like to tone them down a bit .
What I would like to know , In which unit the ST120 or SP14 would have the most effect
if I wanted to roll some tubes ?
Six or so months ago I already rolled out the center tube in the ST120 . Originally I
had the 4024 Mullards I got from Bob when I built the amp in all positions , but I
changed the center to a Telefunken 12AT7 - ECC81 and I like how it sounded better than
the NOS Mullard in the center spot . But just to make sure , last weekend I switched it
back to the Mullard and I still like the Telefunken better . I could tell right away .
I know I read that the center tube has more effect on the sound , but would changing out
the two outer tubes make any difference ?
Or should I try to roll the preamp tubes , I do have two other brands of tubes and a
different rectifier for it ?
I will be adding a PH15 to this system soon too .
I was hopeing to keep it simple . And was thinking that the tubes in the amp would have an
effect on both of the other two components.
I’ve only been listening to the preamp on the first set of output capacitors , the
Mundorfs S/O , so far . I haven’t listened to the Russian PIO caps on the second output
I’m going to do that before I go changing any tubes but I want to figure out what to do
before hand if the PIO's sound similar if I need to .
One other thing . Since this is my first tube preamp , I've noticed that after its warmed up for
an hour or so the volume seems to creep up a bit on it then stabilize . Is this normal with tube
preamps ? Part of the break in process ?