I am very doubtful that the S9 will be able to provide a satisfactory level of sound quality for these headphones. The S17 Pro is noticeably more advanced than the previous models. And Ifi iDSD Signature as well. This device works well with dynamic headphones, but I wasn't impressed by its...

I would not consider buying any Ifi products today, as they are not worth the price in terms of sound quality. They are significantly inferior to products from leading Chinese manufacturers, which offer better value for money.

IMHO the best dongle today is Creative BT-W5. Of the more budget-friendly devices, I really liked Ritmix RWA-359.

I've heard this effect with headphones Hifiman Arya and 1000se, Kennerton Thekk and Wodan, Dan Clark Ether С Flow with almost all high-resolution music tracks. First of all, in complex symphonic works. And I'm afraid that this effect has nothing to do with the "lack of power" - Fiio K9 Pro has...

The difference is not at all that one is "wet" and the other is "dry". The difference is in the detail, the accuracy of the sound and the separation of the instruments.

I have both of these amplifiers. In 50mA mode, they are close in sound. But in 100mA mode, Aune is noticeably better in all respects.

Fiio K9 Pro significantly simplifies the low frequencies of top-end planar headphones. In this sense, it is not suitable for such headphones. The easiest way to formulate this is that the Fiio K9 Pro lacks a general level. That is, with K9 Pro you don't get the full sound that these headphones...

For full-size planars, Serenade is much better than Fiio K9 Pro. The sound is quite good and full-fledged. At the same time, Serenade slightly smooths (reduces detail) the sound and therefore sounds a little simpler than my current main setup - Singxer SDA-6 + Aune s17 Pro. And with Serenade...

I've been using Fiio K9 Pro ESS for about two years, so I had every opportunity to explore its capabilities carefully, comprehensively and with a lot of headphones.

It's pretty weird. Maybe Gustard is somehow overloaded and gives signal distortion at high volume levels?

Unfortunately, Fiio K9 Pro's capabilities are not enough to provide the right sound with Arya headphones. These are very high-level headphones, they need a sound source of the appropriate level. Which K9 Pro is NOT. Especially at low frequencies. Even Hifiman Serenade does not reveal all the...

Hifiman 1000se sounds very nice with Serenade. And at the same time, they have significant reserves for improvement.

In this case, I would first of all think about improving the headphones. For example, up to the Dan Clark Ether С Flow or Dan Clark E3 level. Or Kennerton Thekk.

Aune s17 Pro is a great amplifier. It is one level better (to my ear) than Singxer SA-1. But it makes no sense to add this amplifier to the Serenade. Because the sound won't get any better: the built-in Serenade amplifier extracts the maximum possible from its DAC. My current main bundle of...

I tried using a Serenade with an additional and very good Singxer SA-1 amplifier. This does not justify itself. There is no sound improvement. The built-in amplifier of the Serenade is exceptionally good in itself.