Aune T1 and sibilance? khmmm... that`s the first one. If you are using 6922EH tube then yes, it has sparkly bright highs but no, imo there`s no sibilance.
Maybe it`s mismatch with your cans of you aren`t just used with so sparkly clear highs. Or, maybe your tube is faulty. But nevertheless I definitely wouldn`t say Aune T1 has sibilance. If I use my Superlux HD-681 reds without hw filter then yes, I hear harsh highs & SSsss sibilance but it comes only from headphone. Maybe your cans sibilance came to life because proper dac/amp reveals its true sound nature?
I really doubt that my headphones have sibilance at all in it's sound signature. The bass isn't decent and the sibilance(hissssss) manifests itself at higher volumes.
It was more emhasized in some songs are compared to others though. I have the stock-stock tube 6n23 [or was it the 6n11 or 6n1p?] (not the upgraded 6922) so maybe that is why everything is not pretty great.
Have ordered 4 6es8 (pcc189) tubes and a GE6dj8 tube so hope they sound fine. I've read somewhere that 6es8 tubes don't exactly fit right in a circuit designed for 6dj8 but I've heard some people saying that it sounds fine so I took a gamble.
The textures sound pretty great, am already wondering what my next dac will be, any ideas on what would be a worthwhile upgrade and not a minor upgrade to the Aune T1.
The Aune T1 blew me away but it should have beena lot better, it struggles to drive the Fostex T50RP at 10 gain with some songs and I sure as don't listen to songs at high volumes.
All this is based on what I felt in my initial 2 hours of listening so it may change.