Upgrade my Sonic Frontiers Line-2, or buy a used solid state Pre?

Jmcgrogan2, I'll know soon enough if the amp drives the speakers. The speakers are 86.4db sensitivity, but I don't listen at loud volumes. The xa30.5 actually clips at 130w at 8 ohms. I expect a bigger amp would provide more powerful, detailed bass, but I'm more concerned with the midrange and up. My budget was $3k on the amp. I don't think I could do any better than the XA. From where I'm coming from, I don't think I'm going to be disappointed with the bass anyway.

Adg101, I have a new set of EH tubes. I used to buy NOS tubes, but they've become crazy expensive.

Very Happy with the EH tubes I run in my ModWright. I use EH tubes from Cryoset Certified and have been very pleased with them. 

I recently picked up a set of Daedalus DiDs Isolation Devices which I can't speak highly enough about. Took them over to my Dads system to throw under his Line-1 and it made a huge improvement on his pre as well; really opened it up. 

The SF Line series of preamps are more solid state sounding than an older ARC and CJ tube pre's I agree but not dry. You throw in the right tubes and it's another story. My LS36.5 is a killer preamp but it's not a big fat tube sound either, but I'll throw it up against much more expensive SS preamps any day. Obviously we all have our own opinion on what sounds right.

You already own the SF. I wouldn't give up too soon on it. I have a Pass amp as well and I think you throw on a nice power cord and some DiDs under your Line 2 you'll be amazed. For the money WyWires Silver Juice II is great; it's a very open, transparent PC Get the amp first and play around with your Line 2. 

Good luck

adg101, I’ll throw my VAC amp up against much more expensive SS amps any day. You don’t have to sell me on tube gear, I’m using tube phono, tube preamp and tube amplifier. So yes, I love tubes.

That said, there are some decent SS amps out there, and even some decent SS preamps. Not all tube products are better than all SS products.

You are right, that we all have our own opinions, and in the end, the only opinion that counts is the one of the person spending the money.

Unless you have ever heard a Klyne preamp or phono stage, I would not dismiss them so quickly. That would be as big of a mistake as dismissing a Pass amplifier because it doesn’t have tubes, IMHO.

@jafant , you can search Klyne. Very small, steady manufacturer, whose owners are incredibly loyal, and for good reason. I know more than a few tubeophiles who have converted happily to Klyne preamps.
Yes, preamps is all Stan Klyne makes, and he’s been at it for over 35 years. No digital, no amplifiers, only line preamps and phono preamps. His 7PX5.0 phono stage was the best phono that I have owned, bar none, and I’ve owned $10K tube phono stages.

I had SF SFL-1 (my 1st tube preamp), SFL-2, Line 3 and Power 3.  With my favorite NOS Philip Holland / Amperex 6922.  it's not dry or sterile. 

I had the Line 3 and Power 3 upgraded to SE+ by PCX.   It's an improvement over stock but not worth the $$.  

In the Line 2 + upgrade price range, checkout an used EAR 868, Audio Valve Eklipse and ModWright.

@knghifi , I'll just agree to disagree on the "dry and sterile" comment.

As for you recommendations, while they may be very good preamps, I don't believe that any of them are solid state preamps, which is what the OP specifically stated he was looking for.