It is has been a long time since I posted on the Jadis JA Mk.ll amp. with KT150 tubes. I have tried the telefunken 12au7/12ax7 for driver/input tubes and they are highly dynamic but not as musical as the Mullard 12au7/Siemens 12ax7 tubes which I have settled on. Also the KT 150 tubes take a long time to burn in like maybe 200 hours.
I have now concluded the Gamut d3i preamp./Jadis JA 30 Mkll. amp combination. is staying here long term. I especially like the fact the Gamut is meant to leave on forever with no warm up. The Jadis takes a bit of warm up to show their tremendous magic they have due to the massive transformers reaching internal thermal temp.
I have tried the amp. on my Living Voice OBX-RW and Gamut Rs7i [89 DB] speakers and in my room of 15X20 it is no challenge for the amp. to control the speakers. I also think it is the best bass I have had in my room but remains especially musical/magical top to bottom. I did re-strap the amp. to 4 ohm for the Gamut speakers and maybe noticed more control of the drivers with a slight loss of air and it has no issues on the 8 ohm tap. The amp. sounds more powerful than you can imagine and once fully warmed up a piano tone is shockingly real and never on the edge as in some systems I have heard. The Gamut speakers go down to 22 hz and these amps. have tremendous grip on the bass.
The only rolling in this amp. is with driver/input tubes and it does work for flavor but I have not converted the amp. to lower voltage for the many others it will play. At this point I have no desire to as the KT150's are very good on this amp.
In conclusion, this amp. got rid of the bit of fatness in the old amp. and it becomes much closer to neutral with superior quietness and "you are there" sound staging front to back.
This Jadis amp. certainly belongs on the list of must audition Push Pull Class A amplifiers if you are in the market. I would also highly put the Gamut on that list for a SS preamp. that sounds as natural as tubes and more so than some tube preamps. I have owned.
In the end, the Jadis sheer beauty, musical magic, and simplicity with tubes is a blessing for the asking price. I love it.