I'm using AK120 with TG!334 with BTG Starlight SPC cable. Last weekend I tried SR-71b and Intruder with the pair for about an hour or so at my local audio store.
With the Intruder, I found the combo has too much warm and bass quantity, considering the 334 is quite a warm sounding IEM.
When I swapped the amp with SR-71b, it brings out the mid and treble, but I noticed the bass is slightly roll-off. I don't know what it the output impedance of the 71b, but the 334 is very fussy with high OI, from my experienced with my previou stock AK100 which had 22 Ohm OI.
I only used the single-ended connection, instead of the balance output on both amps as I don't have balance IEM cable.
At the end of the demo, I decided that I don't need either amp for the time being.