Joule Preamp users and other pairing with Joules power amp.

Besides the Joule preamps, the other that Bobby @ Merlin often used was the CAT line, especially for the excellent phono stages built-in. One line I love that wasn't around back then is the Backert Labs preamps, which I think sound great with everything and have the clarity, rhythmic natural drive that would greatly complement your gear. Cheers,
Spencer

One thing I forgot to mention is that if you are looking for the most experienced opinion on Joule & Merlin, you might reach out to Rich Brkich at Signature Sound in Liverpool, NY who worked most of the Merlin rooms at audio shows with Bobby and always featured Joule or CAT. Cheers,
Spencer

Congrats on the amp. I was a long time Joule/Merlin owner. Loved the sound and occasionally find myself daydreaming about buying another Joule amp to rotate into my system.

I used four different preamps with my Joule amp over the years. First was a Supratek Cortese. Fantastic, live sound with a very nice phono stage, but the power supply produced too much heat, which made the heat in my room even worse when used with the Joule amp. I then had an ARC LS-25MKII, which sucked the life out of the sound. I then tried a Cary SLP-98P which was nice but left me wanting more.

Finally went ahead and bought a new Joule LA-150MKII. It worked really well with the amp and I never had a problem with it. The bass and midrange can be beguiling. Not quite as lit up from within as the Supratek that I had, but easy to listen to for hours on end, with a very good sense of immediacy when paired with my Joule amp. Given the used prices of the LA-150MKII, it is definitely worth a try.

Another intriguing possibility for your amp, at least for me, would be The Truth from the Horneshoppe. I recently bought one and can easily imagine it producing life-like, natural sounding music with your VZN-100's. Inexpensive as far as high end audio goes, and comes with a lifetime warranty and money back guarantee if you don't like it.