Fiio K9 pro ESS

[ArthurStein13]

I’m asking myself a simple question: is the Fiio K9 Pro ESS, released in 2021, still a relevant choice in 2025?

I still often see it recommended, notably for its musicality, solid build, balanced output, and its ESS chip, which remains highly appreciated for its analytical rendering. But given the rapid advancements in the field, I’m wondering: at $800/€, is it still competitive compared to newer devices?

I’m indeed looking for something that can efficiently drive my HD660S2 for passionate Classical Music listening…

 

[oleg87]

Not sure it ever was a particularly price-competitive option.
With FiiO themselves undercutting it with the K7, I can't see much of a reason to buy one (unless you need balanced line ins/outs for whatever reason).

 

[RickS]

Je recherche actuellement un bon DAC ESS et une entrée symétrique pour mon Sennheiser HD 660S2 pour écouter de la musique classique. J'hésite entre plusieurs options, notamment le SMSL DO400, mais je crains qu'il ne soit pas assez amplifié.

Please repost in English. Thanks!

 

[ArthurStein13]

Not sure it ever was a particularly price-competitive option.
With FiiO themselves undercutting it with the K7, I can't see much of a reason to buy one (unless you need balanced line ins/outs for whatever reason).

I am currently looking for a good ESS DAC and a balanced input for my Sennheiser HD 660S2 to listen to classical music. I am hesitating between several options, including the SMSL DO400, but I am concerned that it might not be amplified enough.

 

[oleg87]

Pretty much any half-decent desktop amp is going to be sufficient for the HD660S2s, they are not unusually demanding. An amp needs to deliver like 6vrms or 100mW into 300 ohms to reach a deafening 120dB peak SPL, which should be enough volume for any reasonable purpose. A mains-powered desktop amp should easily exceed those numbers.