Review and Measurements of Fiio K5 Headphone Amp

[kombajn]

Hi everyone I just register to ask some questions. I have K5 connected currently to Creative Audigy 2 sound card. I'm planing to buy DAC soon. I was thinking about Topping D10. But that's not the point. My question is how good will K5 be at powering Beyerdynamic DT880 600 Ohm? I had opportunity to buy those cheaply and took it (they will arrived in few days). Will K5 be enough or should I just start looking for new amp as well? FiiO doesn't give any info about power at 600 Ohm. Old FiiO E09K had 1W@16 Ohm and 80 mW@600 Ohm while K5 have 1,7W@16 Ohm

 

[Godfix]

This is a review and detailed measurements of Fiio K5 headphone amplifier. I purchased this unit last fall and it has been sitting patiently for a review. The K5 costs USD $110 including free shipping from Amazon. What is unique about this product is that it has a dock mechanism to mate with the USB connector on Fiio portable audio players:

View attachment 22162​

By flipping the gray door on top of the unit different Fiio players can connect to it. You can then select that input with the front panel switch. In the back there is a USB jack that routes to the portable player, allowing it to be used as DAC. Without it, there is an analog-only amplifier with NO DAC built-in.

The case is metal but it has a paint on it that is normally is used to make cheap plastic look like metal. As such, it looks rather cheap to me. The volume control feels nice though. And it is fairly hefty so sits there without the cables pulling on it.

Power is provided by a laptop-sized 15 volt switching power supply delivering 1.5 amps from memory. So one would expect plenty of power to be available on tap.

There are a set of 3.5 mm jacks in the back that provided balanced output. I did not a 3.5mm to XLR cables so didn't bother testing that. And at any rate, that is more useful with their portable players.

Let's get into measurements and see how the K5 performs.

Measurements
My dashboard for headphone amps involves feeding 2 volts in, and getting 2 volts out ("unit gain"). The Fiio K5 conveniently has a "0 dB" low gain switch for this purpose:

View attachment 22163

Distortion is limited by second harmonic at -108 dB or so. SINAD (signal over noise and distortion) is therefore shy of the 114 dB that its competitor, JDS Labs Atom produces. In other words, respectable but not top of the class.

I am not a fan of SNR measurements (as it ignores distortion) but you all want it so here it is:
View attachment 22164

This ranks well:
View attachment 22165

Frequency response is rule flat and excellent:
View attachment 22166

Output impedance is likewise 1 ohm which is low enough for just about every headphone load:
View attachment 22167

The most important measurements for headphone amplifiers is power versus distortion+noise. Here it is using 300 ohm load:
View attachment 22168

Noise level dominates the sloping down part of the curve and there, the K5 almost keeps up with the JDS Labs Atom. But then distortion starts to set in around 10 milliwatts and performance degrades some (gracefully). Importantly the power output is half of what the Atom produces. At 121 milliwatts though, it easily clears my requirement of more than 100 milliwatts to provide good power for high impedance headphones.

At low test impedance of 33 ohm we are measuring current delivery capability:

View attachment 22169

Here, the Fiio K5 becomes noisier than Atom and again, distorts more. Power output is similar though and very good at > 1 watt.

Intermodulation distortion versus output level (and hence power) repeats the same story:
View attachment 22170

Low and mid-gain again show somewhat more noise level than JDS Atom (dashed lines). High gain though was much worse. Not sure what went on there.

Channel matching is very good until you get down to low levels where it goes nuts:
View attachment 22171

Given the 0 dB low gain setting, hopefully you don't have to operate it in that region much. FYI I changed the output level to relative dB so that you can tell the amount of attenuation (red) for every imbalance level (blue). Let me know if you like that better than previous graphs that showed the voltage instead.

Listening Tests
Jogar minhas faixas de baixo pesado no Fiio K5 enquanto dirigia meus fones de ouvido de alta impedância Sennheiser HD-650 resultou em um som muito satisfatório e altos níveis de potência. Eu poderia literalmente vibrar os lóbulos das minhas orelhas com ele. : D Infelizmente, embora você tenha ampla potência entre 12 e 1:00 horas, indo além disso, pude ouvir a distorção de graves no amplificador antes do driver fazer o mesmo.

História semelhante surgiu com o fone de ouvido de baixa impedância Hifiman HE400i. Muita e muita potência, ótima dinâmica, etc. até que você passou das 2:00 às 3:00, onde a distorção de graves entra.

Observe que, fora dos testes, eu não precisaria ir para a região onde a distorção era bastante evidente. Portanto, no uso prático, há bastante potência livre de distorção disponível.

Conclusões
Não consigo encontrar nada de errado com Fiio K5. O problema que ele tem, porém, é o campo de batalha impossível criado pelo JDS Labs Atom com sua combinação de alta potência e extraordinária baixa distorção. Comparado a essa referência, o Fiio K5 fica um passo atrás.

Estou feliz em recomendar o Fiio K5 se você precisar de sua capacidade de dock ou como seu controle de volume, etc. Bom trabalho foi feito aqui pelo Fiio.

Esta unidade está disponível para venda se alguém estiver interessado.

------------
Como sempre, perguntas, comentários, recomendações, etc. são bem-vindos.

A neve derreteu, mas agora preciso do dinheiro da gasolina para ir buscar todos os pacotes empilhados no correio. Portanto, considere doar dinheiro usando:
Patreon : https://www.patreon.com/audiosciencereview ) ou
atualizando sua assinatura aqui por meio do Paypal ( https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054 ). [/ QUOTE]


Olá meu amigo..

Para um fone de ouvido Phillips Fidelio X1s

Seria uma boa opção?

Schiit Magni 3 ou Topping L30 também seriam interessantes?

 

[Nathanael]

Hallo,

I'm interested in to the Fiio e17k + Fiio K5 Kombo, mostly because of the balanced output. I've got three questions and would be very happy if someone could answer them:

1. Afaik the volume of the unbalanced output is fixed. Does anyone know if the volume of the balanced output is fixed too?

2. Does the gain settings apply only to the headphone out or also to line out? (for example: Fiio K3's gain settings aply to line out too, Fiio K5 pro's not)

3. Is that true that a balanced connection between the dac and my active monitors can help eliminate grounding loops and other annoying noise from the PC?

Thanks for all answers!

 

[AnalogSteph]

3. Is that true that a balanced connection between the dac and my active monitors can help eliminate grounding loops and other annoying noise from the PC?

Definitely. Unbalanced between a typical PC and typical active monitors is pretty much inherently broken.

I'm just not sure whether this combo would be the right tool for the job though. While the slightly unusual choice of 3.5 mm jacks can be adapted without too much hassle, FiiO's FAQ item also notes

Note: the balanced line outputs only carry a signal when the K5 is docked with the FiiO X1 2nd gen, X5 2nd gen. X5 3rd gen or X7.

No word about the E17K.

You may want to look into the world of USB audio interfaces instead. Depending on your needs, some may be adequate for driving your headphones out of the box, while many more will qualify with an external headphone amp "afterburner". If your PC already has USB Type C to offer, the Audient iD4 MkII would be a hot candidate, the MOTU M2 is also decent, and with an external amp the SSL 2, Tascam US-2x2HR and Steinberg UR-22C would be joining the club. (@Julian Krause has a rather massive table for headphone output performance that makes a good reference.) Feel free to open a new thread in the newbie department.