Tubes or simply the characteristic of the Pre-amp?

I've recently acquired a much covetted piece of gear for myself, a Sonic Frontiers Line 1. With little intro, it has many of the features that I've been "desiring" balanced ins/outs, 2 se line outs, headphone - drool drool drool etc. etc.

Well, I pulled out my beloved Quicksilver Remote Line and replaced it with the SF line 1. What struck me as odd was that the bass seemed "light weight" and the upper bass and lower midrange had less initial presence and lacking lead-in transients.

I swapped out the rear-most tubes of the SF line 1 with the same tubes from my Quicksilver and it improved imaging and tonal balance but still left the upper midbass lacking.

Is this a characteristic of the Line 1? The tubes used are Amperex White Label PQ's from late 50's and they are excellent in the Quicksilver pre.

I know SF makes great gear, I own an Anthem Amp 1 and find parts and build quality leave little to be desired.

Should I shuffle the tubes around? The line 1 has 6 - 6922/6dj8's as opposed to the Quicksilver's 2-6dj8/6922 tube stage.

The current tubes in the line 1 consist of Amperex White Label PQ's, and NOS Tesla Gold pins in the remaining positions from back to front of pre-amp respectively.

Pros of the Line 1? I find air around instruments, width of stage, layers and imaging have increased in a very nice way however, I have lost some of the dynamics from the Quicksilver. The Line 1 is also just the slightest quieter but also seems lower in gain.

Is it the positioning of my tubes, the tubes themselves or the Line 1 itself that has stolen the upper bass and lower mid bass regions?

I can definitely "live" with the sound, the only thing is that I feel that I may be giving up what the Quicksilver was able to give in spades.

I thought that by pulling the Amperex's from the Quicksilver I would hear similar performance from the Line 1.

When I first installed the Amperex White Labels in the Quicksilver the difference was NOT subtle. Bass became almost overwhelming to where I had to move the speakers out in to the room and away from the wall more than the previous tubes.

Thank you to all and sorry if my question is confusing or unclear.

Happy Listening,

I've owned both and the Line 1 is more neutral sounding than the Quicksilver (less tube sounding). My guess is that is the difference you are hearing. Tubes do make a difference but I don't believe the two preamps will ever sound alike.
The good news is that you have a great preamp. (I used to sell them, a long time ago in a galaxy far, far away.) A great piece of tube gear will sound like the tubes and not have much character of its own. And, since the Sonic Frontiers is a great piece of gear, it will, indeed, sound like its tube.
Sonic Frontiers used to recommend Valvo's for your preamp--until they ran out of them! Although, those aren't the best around.
Your Amperex's are fantastic tubes, so I would stick with them.
But, if you want to beef up the bass, I would recommend that you get a pair of mid-sixties Siemens & Halske E88CC's, or CCa's--not the ones with the D-getter. They will have an O-getter.
You should put them in the middle row--which is the most important one--put the 6922PQ's in the front and rear rows, and pull out the Tesla's, for now. The Tesla's are great. Don't get me wrong. I just think it would be easier for you, if you rolled, systematically.
Listen with the Siemens' for a while. Then, try swapping out the PQ's in the front row for the Tesla's. Finally, put the PQ's back in front and try the Tesla's in the third, least important, row.
If you do decide to pick up some Siemens', this guy on the 'gon has some good ones for good prices. This is the internal link to his ad:
I hope this helps.
wether tube or ss preamps make the biggest difference in a system. there many things that count .tubes do make a big change in a preamp I would you try EI tubes . make sure that you buy them through a honest seller and not the best deal on e bay . have them mached. good luck
Order of importance,
Middle row
back row
front row

Run the Amperex PQ tubes in the middle and the back row, Tesla in the front row. Try that and post back.

I also recommend Herbie's HAL-O tube dampers.
Install them near the top fat part of the tubes.
having lived with and auditioned many preamps using 6dj8 and equivalent tubes, i find it difficult to find such a tube that provides the classic tube sound or for that matter, bloom, or richness.

the 12 volt tube or a 6fq7 is a better way to go to obtain the sound of the golden glow of tubes.
Jea48's right. I got the importance of the front and back rows confused. My bad. Also, he is right that you should try his suggestions, first. (They're a heck of a lot cheaper, for one thing!) I don't know why, but I thought you had told us you had done that tube swap, already.
I'm not sure if Herbie's Ultrasonic dampers will give you more bass, or not. But your tubes will, definitely, sound better, less harsh. Maybe more apparent bass. (I use them, myself.) Actually, Herbie does make a specific type of tube damper to add bottom weight. It's called the "Peek" series. But, I haven't tried them, yet.