Prima Luna or sonic frontiers or audible illusions


I have an audible illusions 2d. It has served me well for many years. But, it seems I have the upgrade bug of late. I am looking to increase the imaging if possible of my system and am curious if upgrading to the modulus 3a would be a significant improvement. Or, would I be better served with a sonic frontiers sfl1 or line 1/2? Lastly I have to admit that the prima Luna prologue is appealing bc of the exposed tubes. Not sure on the sound though...any advice? Any other choices that have the tubes on display?
2out2sea
I have always heard good things about Chris and sonic frontiers, but I would love to know what ya'll hear as sonic differences bw each pre. The prima is the most tempting bc of the exposed tubes. Aesthetically I just like the exposed tubes. However sound trumps looks by a large margin. Is the prima going to image and soundstage like the ai or sf? Is the sf or upgraded ai going to best my older ai? By what margin? I find it hard to believe I have already reached the dollar/cost threshold...
I purchased an Anthem Pre One by Sonic Frontiers to replace a Nakamichi. The phono section was very noisy despite the Johnson Bros. suggestions of numerous tube replacements. Their local dealer had to eat the cost and for an increase in price I selected the well reviewed AI M3A. After stone walling their retailer, within weeks the Johnson's took their Pre One Phono off the market releasing the non phono version only.

The AI had very limited attenuation. Four or five clicks of the stepped attenuators before it was too loud or too soft regardless of switch settings or main board revision. In a very short time the dual mono attenuation became a pain. My family hated it. The attenuators wore out in a few short years and despite an absolutely definite two week estimate for the repair it took over four months.

In my experience these are two of the shadiest manufactures I've had to deal with.

I'd suggest looking for an older used VAC pre.
I would have to agree that the Modulas is by far the better sounding preamp of the three, even if your main listening is done with your digital front end,with that said the phono is why you buy the Modulas 3A or 3B. There is a factory refurbished 3A for sale now on Audiogon with warranty for a little over 1,500.00 and it has the John Curl phono boards. I currently run the 3B with the JC board, had it built 4 years ago to replace a Modulas 3A. Also have a Lamm LL2 line stage coupled to an Allnic 1500 phono that serves in the same system, not better than the Modulas just different. Tooblue.
good call on the phono section...i don't need it. i'm a digital only guy. i know that is sacrilege, but it is what it is. a line stage only will serve me just fine. unfortunately i seem to recall reading that the modulus performed better than the linestage.

i have had good luck w/ my ai 2d, i hate to hear that others have had bad luck. it's the outboard power supply and dual mono that makes the ai appealing. similarly the prima was attractive b/c of it's dual mono configuration.

i looked at the vac preamps. not sure how the standard stacks up, but i can't afford to spend 3-4k on a used pre. 2k is the top of my budget unless there is something that will be truly earth shattering.

can anyone speak to the specific attributes of the aforementioned pre-amps? my 2d throws a big soundstage, but the imaging is a less pinpoint.

thanks for the advice.