>>213cobra, do you have the Jasmine?<<
I do own the Jasmine. It is switchable for 55db or 70db gain. Who cares what Musical Surroundings says? They sell a lower-gain unit. Sure, if you design a circuit to deliver more gain using inferior methods or parts, sound will suffer. But the Jasmine is very carefully designed and executed. It's quiet, too. It sounds better than the majority of phono preamps, regardless of price. You can use the 55db gain position for the Delos.
On the Jasmine, you get 47Kohms impedance on the MM 55db gain setting and choices of 50/100/250/1k ohms on the MC 70db gain setting. What more do you need? Use a transformer into 47k, which is what you should be doing anyway.
>>What cartridge are you using, if you are, to be so confident the Jasmine outperforms the other preamps?<<
Let's see....Right now, I variously use Denon DL103D, 103R, DL305, DL103M, 103FL, 103Gold, Zu103, Ortofon SPU Synergy, SPU Meister Silver, Signet TK9LC, and I've listened to Koetsu Urushi Vermillion and Black Goldline through the Jasmine. I use some of these cartridges with MC SUTs into the 55db gain position, which is preferable in general for MC carts, but straight into the 70db gain position, they all sound magnificent as well. I use Koetsu, EAR MC3 and Cinemag transformers.
The Jasmine isn't the only phono stage I have. I also use Audion Premier, Wright WPP100C, the MM phono section of an Audion Premier full preamp and a Bel Canto Phono1. I put the Jasmine up against a Manley Steelhead and the Manley was left crying in a corner, but that wasn't surprising. It humiliated a K&K.
>>Considering how many positive reviews the other units have got, that's quite a ballsy statement!<<
I've been spending my own money on serious audio for 40 years, going back to the time when you didn't buy a separate phono stage because full preamps with great phono sections were routinely offered. I don't need reviews to validate my choices and I hear a LOT of gear. I've had much more expensive and cheaper phono preamplifiers and while I'm not saying there aren't better phono preamps available, this one is a genuine gem, a sleeper in the best tradition, and it will make better, higher-fidelity music than any competing item on your original list.
But understand I think every phono stage on your list is fully credible. These are all good phono stages. It's just that the Jasmine is better. It would cost far more if it were made in Europe or the US, instead of China, but its Chinese origins do not reflect *any* lessening of design or execution. The designer is seriously talented, he knows good sound and how to get it and his build quality, parts selection and general execution are beyond reproach.
If you like reviews, here's one worth reading:
http://www.jasmineaudio.net/DAGOGO_Review_Jasmine_Audio_LP2_phono_stage.pdf
Phil