FiiO K7 vs K11

These two get compared constantly, and usually on the chip — two AK4493S in the K7 against a single CS43198 in the K11 — which is the least informative row on either sheet. What actually separates them is the amplifier stage, the headphone power that follows from it, and one measurement where the cheaper product wins by a margin large enough that it needs explaining rather than ignoring.

Every row where the two sheets disagree

The power gap is real and it is consistent

2.35× at 32 Ω, 2.33× at 300 Ω. That consistency is itself informative: it says the K7’s advantage is a bigger voltage swing rather than a different behaviour into a hard load, and it means you can trust the ratio across the impedance range rather than having to check each point. In volts into 300 Ω it is 6.5 V against 4.2 V from the single-ended socket.

Whether 2.3× is worth the price difference depends entirely on whether the K11’s figure was already enough. 520 mW into 32 Ω is a great deal of power for a 32 Ω headphone; the gap only becomes a reason to spend more as impedance or insensitivity climbs, which is exactly the case our high-impedance page is about.

The row that runs the other way

FiiO publishes a line-out signal-to-noise of ≥ 126 dB for the K11 and ≥ 116 dB for the K7. Ten decibels, in favour of the cheaper box, on the output you would use if you were feeding an integrated amplifier or a pair of powered speakers rather than headphones. Both figures are A-weighted and both come from FiiO’s own parameters pages, so this is as close to an apples-to-apples comparison as published specifications get.

We are not going to invent a mechanism for it. The plausible readings are that the CS43198 and its surrounding analog stage simply measure better on noise than the dual AK4493S implementation does, or that the two numbers were taken under conditions FiiO has not fully described. What we can say is which figure is missing on each side: the K7 publishes a line-out THD+N of < 0.0005% and no output level; the K11 publishes an output level of 1.95 V RMS and no THD+N. So neither sheet is complete, and the one row where both are populated favours the K11.

The analog input nobody mentions

The K7 has an RCA line input. The K11 does not, and neither does the K11 R2R. That single row changes what the product is: with an analog input the K7 can sit on a desk as a two-input preamp and headphone amp, taking a phono stage or a CD player alongside your computer’s USB. Without one, the K11 is a DAC that can only be fed digitally, and anything analog needs to go somewhere else first.

If you own a turntable, this is probably the row that decides it, and it is worth reading alongside our DAC-versus-preamp explainer, because a line input is the thing that makes the difference between the two categories collapse.

Where the K11 R2R fits

The third pick is the same chassis and the same amplifier chips as the K11, with FiiO’s discrete resistor-ladder converter in place of the CS43198: 192 thin-film resistors per channel pair at 0.1% tolerance. Its headphone power sits just below the standard K11’s in OS mode — 460 mW at 32 Ω and 50 mW at 300 Ω single-ended, 220 mW at 300 Ω balanced — and it adds a coaxial output and three independent gain curves.

The number that defines it is the line-out THD+N FiiO publishes: “About 0.025%”, with FiiO’s own hedge included. Against the K7’s < 0.0005% that is roughly fifty times the distortion. We rank it third here and we would still recommend it to someone who specifically wants an R2R ladder DAC and has read that number first.

Which should you buy?

Headphones first, and especially high-impedance or insensitive headphones on a single-ended cable: the K7. An analog source on your desk: the K7, because nothing else here has the input. Feeding an amplifier or powered speakers, with headphones as a secondary use: the K11, on the strength of the 126 dB line-out figure and the money saved. A balanced cable and a 300 Ω headphone: the K11, because it published the number and the K7 did not.

Both of them appear on our DAC and amp combo roundup, where the K7 ranks first on the 32 Ω column, and the K11 also turns up in our compact-desk shortlist.