My first contact to KS Parks products is the Silvaweld 650 phono stage, which already has the famous 5U4G Rectifier in the PSU. This Phonostage is now with a friend and I can listen regular to it. The integrated J-Fet is great in sound and it is difficult to find a step up, which can beat the internal J-Fet stage. Comparing Allnic 1500 and Silvaweld can be done with the same external SUT using both the MM inputs. I never did it
When we compare J-fet and SUT on my friends Silvaweld, the impedance of the chosen cartridge was always critical, without matching the SUT 100%, the J-fet mostly wins, as more flexible.
KS Park is using more or less the same SUT type in his current Phonostages. I am looking forward to his new silver SUT, planned for 2021. I am not sure if this Silver SUT will be only available as external upgrade or if the SUT will become standard for the Allnic 8000 Phonostage.