What is a very nice sounding tube preamp?

I have a Manley Jumbo Shrimp that has excellent spatial and depth of stage characteristics.

I've really enjoyed my Joule LA 100. It's a keeper! Although I'm currently using an Aesthetix Janus Signature, I'm hanging on to my Joule.

If transparency is what you seek, check out SAS Audio labs preamp.

The OP has probably found a preamp however I feel that I must offer my 2cents:

I finally found a Vac Standard Preamp. I entered the Vac family in October of 2012 with a Renaissance 30/30mkII and the Standard seemed like a good choice. Speakers are Silverline Sonatina I.

Standards/LEs don't come up for sale often and it's easy to see why. The Standard seems to be known for its soundstage and musical presentation. These were immediately apparent.

Just as soon as I had accepted the Standard into my system. I found a Standard LE which I bought. After 2 months of swapping back and forth I decided to keep the Standard LE because it has a remote.

As noted in almost every VAC thread I've read: Kevin Hayes and his company are a wealth of information and stand behind their products.

I love my Standard (and LE).