Ever since I heard my first 300b tube amp, I knew I was hooked and that I have to have one. After much research, I took my chance and bought the Cayin HA-300 from Musicteck. I am definitely not disappointed with this amp. If you read the handful of reviews out there, they are all pretty much true.
On my system with the Chord Qutest DAC and Audeze LCD-3 Fazor (all cables from Morrow Audio), I am hearing a lot more dynamic musicality than ever before. There is a heightened sense of realness and presence that elevates the Audeze LCD-3 from what I thought was possible without having to upgrade to the LCD-4.
In addition to the music being more visceral, the soundstage and treble extension have opened up. The mids are still nice and lush, but vocals are no longer as veiled as my previous amp can sometimes exhibit.
The bass is still quite good. About the same amount of slam as before, but there's more tightness and articulation. Overall, instrumentation separation, resolution, and transients have improved. Another thing I notice is that with a highly resolving combo like what I have now, poorly mastered music sticks out like a sore thumb, while beautifully mastered tracks becomes even more enjoyable.
Interestingly, even though my Qutest outputs RCAs into the HA-300, when I switch over from Single Ended 6.3mm to 4-pin balanced XLR, I get even clearer mid-treble and treble, with just a slight loss of bass, which also came in tighter than before.
I would say that this tube amp is just left of neutral, but not overly buttery warm as some tube amps can be. Of course, all you need to do is roll some tubes to change the sound signature. These stock Shuguang WE6SN7 and JJ Full Music 300b tubes work very well with this amp, and I can't to explore other sound by rolling my tubes.