The Feliks Echo Mk2 is a desktop tube headphone amplifier retailing at 899€ in Europe. It is the entry level model of
the Feliks Audio line-up a company based in Poland. But i think entry-level is not the correct description regarding build & sound
quality of this piece of audio gear.

Unboxing, Build & Connections:

Even though it is a desktop unit it has quiet some heft to it you notice this when unboxing the unit. The build quality is honestly
remarkable, it is build like a tank. The combination of quality medal & wooden side panels give this unit an exquisite look and feel.
Beside the amplifier you find 2 power tubes (6N6P), 2 driver tubes (6N1P) and of course a standard power cord.

The Feliks Audio Echo Mk2 is a pure tube headphone amplifier with an OTL design having a power output of 350mW. This headphone amplifier features
three selectable RCA audio inputs on the front panel, as well as a mute function. The massive alps-potentiometer volume knob on the centre is amazing, it so
smooth and satisfying to handle. Finally there is only one 6.35mm Single Ended headphone jack located on the left, no XLR or 4.4 option this is a pure
single ended amplifier through and through.
On the rear panel there are 3 RCA analogue inputs, and also an RCA pre-out so it can also be used in an audio chain to feed some powered speakers
or power amps. Finally on the right there is an on/off switch and power socket.

Sound Performance, Pairing & Specs:

In general tube amps have the reputation to sound more analogue like compared to solid state amps and i can definitely confirm when comparing it to
all solid state amps that i have on hand and had in the past. There are some solid state options like a Class A Amps that tend to sound warmer but not quiet
to the point that a tube amp does.
This OTL Tube amp is primarily designed to work with high impedance headphones (superior to 50 Ohms) at least that's what has been advertised
through the documentation and research through the web and yes that was the outcome through all the listening experiences i had with the Unit.
It didn't seem to like my Planar Headphones very much, the Hifiman Ananda, the HE-6 SE V2 and the DC Noire X all had "issues" on the Feliks amplifier,
the Low end got distorted when turning up the volume so i quickly decided to stop the listening sessions with those 3 headphones, the only planar
headphone in my collection that worked better was the HE1000, the listening experience was great with this one but on some tracks where the bass was
reaching a bit deeper at higher listening levels i could also spot some distortions which left me a bit disappointed. Gladly this didn't happen
when i switched over to my DD collection of headphones on the contrary they all sounded great on the Echo Mk2, especially with HD660s2 & HD620s2.
With those 2 headphones the magic unfolded and this seemed to be the perfect match. I don't exactly know what happens with those 2 Sennheiser headphones
but they seem to transform somehow with the Feliks amplifier, adding airiness, warmth and smoothness compared to what solid state amps are able
to expose on these. Another very nice pairing was with the ZMF Bokeh Closed, that combo sounded also fantastic.
With IEMS this amplifier pairs surprisingly well no background noise, no hiss, no issues at all at least with the IEMS i tried, from the
low budget Truthear Gate, the Meze Alba's, the mid-tier Softears Volume S every IEM worked just fine. On the Source side, i have fed the Echo Mk2
with different DAC options, from AKM, ESS, Burr-Brown to R2R Ladder Dacs and it worked well with all them there were some slight changes in flavor
but no drastic changes, i think it will work well with most of the DACS out there and will come down to individual preference.

In terms of comparisons, i don't have other tube amplifier on hand right now, so against solid state amplifiers of the likes of a nearly similar
priced Aune S17 Pro, i would say that it performs very well while the S17 Pro being slightly superior in terms of technicalities, versatility
and headphone pairing.

Final Word:

The Feliks Audio Echo mk2 is a great option to get a taste of tube amplification at a quiet affordable price, with some caveats though. Headphone
pairing is very important, whilst high impedance headphones seem to be the best fit for this amplifier, some low impedance planar headphones at
least with some of them it seems to have issues. Taking everything into consideration built, performance and price i think this is a fantastic amplifier.
Paired with a 600 Series or and i guess even 800 series Sennheiser headphone it could be a match made in (almost) heaven.