Jadis JA30 Mk2, how great???

As an owner of Jadis amplifiers, I also obviously feel they offer beautiful, glorious sound.

In addition to your power cord experience, I've found they show as much sensitivity to tube rolling as any amplifiers I've come across.  It amazes me how far you can push the sound in whatever direction you want to head.  Driver and output tubes more so than the input, and I recommend starting with them, though the input tubes also definitely need attention.  As time passes, you should experiment.  You can REALLY improve things from where the factory starts

@daveyf, I ran the Mullard 12AX7 for a while, and felt happy enough. They took my DA60 up a few steps from the original Ei, and offer a warm, rich sound. Hard to believe, but the dirt cheap Shuguang triple mica 12AX7B aka Silver Dragon handily eclipsed them. In fact, our audio then held a 12AX7 tube shootout at my home, and the Shuguangs placed in the top 3, and beat out some longtime highly regarded tubes. The Shuguang offer a more open, transparent, and balanced presentation, without diverging into harshness or anything unpleasant. Unless you really feel devoted to the pipe and slippers sound, you can skip the Mullards for the Shuguangs. You might also consider the Psvane, which descended from it. I did settle on a vintage 5751 variant, and they actually won the competition. But at about 20X the cost, you wonder if it makes sense.

@inna, I’ve used a variety of loudspeakers with my Jadis amplifiers - Coincident Digital Master w/Troubass subwoofers, Consonance M15 horns, Fried A6 & Studio V & Valhalla, Horning Perikles, Merlin TMS & VSM, Quad ESL57, Tidal Piano, and a few others. I still own the Coincident, Fried, and Quad.  That’s more a reflection of hearing that I owned way too many speakers, and not necessarily a reflection of disliking most of the others

@inna, the best person to offer opinion here would be my very close friend, The Doctor (Mechans), as he’s owned the DA60 and JMlabs loudspeakers at the same time, and brings an incredible wealth of knowledge.

Personally, I feel the larger (4+ output tubes) Jadis amplifiers would represent an ideal match with the JMlabs speakers. Especially, given your insight. My Orchestra Reference offers fixed bias and 2 output tubes per side. As such, lower frequencies are not its strong suit, and that circuit topology presents a more forward presentation, neither of which would complement the Utopias. My DA30, while moving to cathode bias, also doesn’t present the best low frequency performance or control. However, when you move up to the DA60 / DA88S with two more output tubes per side, things really move to the top shelf. You get incredible soulful, rich, full-bodied sound, with the type of lower-end slam and performance that sits as the perfect foundation for the entire musical spectrum.

@daveyf, I’ve been around and own both older and more recent Jadis amplification. My amplifiers illustrate the evolution, though the differences don’t go anywhere as far as some try to tell me. So much of it comes down to output tube selection, as again, my experience has shown tubes more critical to the end result than most other amps I’ve encountered. The company tends to prefer the larger tube types, and have evolved from 6550 to KT90 to KT88 to KT120 to KT150 through the years for reasons related to sonics, reliability / durability, and availability. Personally, I prefer all of them with EL34 output tubes, as I feel the midrange rises to a level that few other products attain. 

Regardless of where you head, I hope you enjoy as long and wonderful relationship with your amplifier as I have, and excited to have you as part of the small group of Jadis owners