KAEI TAP 2 with Moondrop Dawn (3.5mm) on OnePlus 8T using UAPP
(SELF BOUGHT)
Sensitive/low-impedance test:
Softears Volume (5ohm, 123.7db/vrms@1khz) :
(TUBE ON, LOW GAIN) Can still hear the music (extremely low volume though) with the amp being on at 0 volume, which is kind of annoying. The volume wheel´s volume (no pun intended) control is excellent and allows for very fine adjustments. ZERO NOISE AT ALL even without music playing, although if you turn off the music and raise the volume to around 12 o´clock there is some noise
(TUBE OFF, LOW GAIN) 0 volume still has some music playing although slightly louder as with the TUBE OFF the volume overall is actually louder. Control over the volume is pretty much the same in that it has excellent control BUT since it is louder overall, it does mean that it gets louder quicker. No tube noise from it even with the wheel turned all the way to the max (no music playing obviously) but there is some very slight hiss in the background at that point which isn’t really a problem since no sane person will listen that loud.
(TUBE OFF, HIGH GAIN) Same as before but even worse volume control since it gets quick really fast. Hiss is more present and at ALL volumes while at max volume the hiss is much louder.
(TUBE ON, HIGH GAIN) same as with tube OFF, there is now hiss present at all volumes AND at 9 o´clock the tube noise kicks in. Volume control is slightly better though as the volume is a bit lower than without the tube activated as mentioned before.
Comment: You will have no issues AT ALL using sensitive and low-impedance transducers.
POWER test:
Ruler (Planar, 50ohm, <92db):
(Tube ON, LOW GAIN): Cannot hear music at 0 volume. Playing at around 1-2 o´clock. ZERO noise at all volumes and no hiss.
(TUBE OFF, LOW GAIN): Playing at around 12-1 o´clock.
(TUBE OFF, HIGH GAIN): playing at around 10-11 o´clock. No noise nor hiss at all.
(TUBE ON, HIGH GAIN) playing at around 11-12 o´clock. No hiss at all, tube noise is very slightly present at max volume.
DIY 500ohm BUD (500ohm):
(TUBE ON, LOW GAIN): Cannot hear music at 0 volume. Playing at around 12-1 o ´clock. At max volume, there is an extremely tiny tube noise that is present.
(TUBE OFF, Low GAIN): Playing at around 11 o´clock. No hiss nor noise at all.
(TUBE OFF, HIGH GAIN): Can hear music at 0 volume slightly. Playing at around 9-10 o´clock. No hiss nor noise at all.
(TUBE ON, HIGH GAIN): Can hear music at 0 volume very slightly. Playing at around 10 o´clock. Tube noise is present a bit at max volume, no hiss.
Comment: Can drive pretty much anything.
Source memeing: Tube on or off honestly really doesn’t sound that different too me, the Tube on mode might be very slightly smoother, warmer and with looser/slower bass compared to the tube off mode. But extremely hard to tell since the volume changes instantly with the different modes. I might prefer using low gain compared to high gain simply because you get a bit better volume control (doesn’t go loud as quick).
In conclusion, this is a damn powerful amp that will drive anything and without any issues with noise nor hiss with the most sensitive iems. While this does count as a tube amp (well, hybrid) you should think of it more as an SSD amp with tube glow.