Preamps: Spectral versus Edge?

I'm ready to upgrade my preamp (Audio Illusions Mod 3) to power my Atma-Sphere MA-1 OTL tube amps, which drive Sound Lab U-2 full-range electrostats. The digital front end is by Spectral, as is all the cabling (MIT, etc.). I think solid state preamplification is the way to go here, and I've heard great things about both the Spectral DMC-15 and the Edge Signature 1 preamp. Both are very hard to audition anywhere near here. Any thoughts?

In response to your question regarding Spectral vs Edge: I wouldn't purchase either without an audition in your system. I've owned Spectral (DMC12/DMA150/SDR2000/3000), but have not heard Edge. I do know for a fact that Edge will let you have a home audition(25% discount if you want the option to return it vs 35% discount without return option). To get this deal you must contact Edge directly. I would also consider Bat in your price range(VK31SE). Hope this helps.
Please note: Edge does NOT offer blanket discounts, nor are we focused on direct sales. Such a practice would defeat the purpose of setting up dealerships and the trust therein. The few items that we have sold at discount directly to consumers include older models that have been used for demonstration and or are prototypes.

The following decribes the exception.

When someone is without a nearby dealer, we will refer them to a dealer that will assist them. If the dealer is unable to service them due to a lack of inventory and is not prepared to purchase the product to service them, only then will we work directly with the customer. And only then will we take into account the shipping fees as representative of a fair discount.

Edge Electronics
As a former Spectral DMC20-II owner, I'd recommend proceeding with caution. There gear really does a poor job holding its value. I bought used, and still got crushed when I sold it.
Their gear can sound superb in the right system, but it is finicky as to what you match it with.
Why don't you consider the Atma-Sphere pre, or other tube pre? Seems to me that would help preserve the purity of your MA1s. The Sound Labs will certainly show you clearly whether or not whatever you choose is a good match.
Another suggestion is to check the SoundLab or Atma owners groups, to see what others with them are doing...