I use the Corda Soul primarily as a preamplifier in a stereo speaker setup with Purifi-based class D power amplifier with XLR analog inputs and Swedish Marten speakers. The sound quality of Corda Soul in preamplifier use was a big surprise to me, as my previous preamplifier was not bad at all, and with Corda Soul I felt like entering an entirely new level or class in terms of sound quality. That big difference alone would have covered the big price of the unit, and then you have all those DSP controls - and a top class headphone amplifier! Yes, it is primarily designed as headphone amplifier, but in my use case I get even bigger value as a preamplifier. When doing late evening listening it is straightforward to power off the power amp and connect my Focal Clear Mg to continue listening without consideration of sound level disturbing anyone.

I use Corda Soul only with Focal Clear MG headphones via low impedance headphone output. Sound is clear, dynamic and ”embracing”. It is easy to pick any old favorite music album just out of curiosity, i.e. what new I could hear on a familiar album. I am not really able to compare Corda Soul to the higher league competition in the headphone amps market. Simply put, it is hard to imagine what more I could hear from the Focal headphones with any other headphone amplifier. Maybe more bass or more biting guitars with metal music, but that’s about it - and I haven’t really tested the DSP that much yet.

I have also Corda Daccord FF and Corda Jazz FF in a desktop setup, and I can of course say that even though the Daccord has same DAC chips and Jazz has the FF implementation as well, there is obviously improvement in sound quality with Corda Soul. I tested Corda Soul for comparison to the old desktop setup briefly with single-ended cable adapter, using Sennheiser HD660S and Beyerdynamic DT880. I felt that the differences are not so big if using single-ended cables with Corda Soul, still the ”higher league sound” of Corda Soul is noticeable.

Corda Soul sound signature is clearly audible both in headphone use and in loudspeaker use. Clarity is most obvious quality factor, especially with human voices. Bass lines can be easily followed and ”spicy”. Soundstage was greater and more accurate than I could expect, especially with loudspeakers. Higher midrange or treble is not fatiguing at all, and is quite lively and ”sparkling”, highs are popping up and chiming everywhere. Actually, the only doubt I have regarding the sound is whether the treble is natural or there is some excessive ”stardust” or ”FF black magic” involved. I can imagine that because I’m mostly listening to studio music, it can be also the artificial nature of mixes on the records I’m hearing.

Daily use as preamplifier is simple enough, even though this unit is designed more for desktop nearfield use. Teaching your existing IR remote is a nice solution. In short, it was better than I expected. I also realized that the trigger out connection would not help that much, if also using as headphone amplifier, because the power amp would play the same output as the headphone amp. Well, who would have Corda Soul and NOT use it with headphones…Jan also offered to make modification for trigger out if needed. The good thing in preamplifier use is that you can connect virtually all audio with digital inputs, so Corda Soul truly is a capable audio center, with the limitation of manual input selection from front panel. I even connected my 15+ years old Sony CD and MiniDisc players with digital, and the sound is excellent. Additionally, the DSP practically gives EQ functionality to adapt sound to your taste and acoustics. I measured the response in my room using REW and playing with the DSP controls, first settings were quite easily guessed only by reading the manual and remembering the bumps of previous measurements.

Notch filter seems highly valuable for headphone resonant frequency mitigation, in case of Focal Clear Mg I couldn’t hear that big difference, although I didn’t have any clear target frequency. Crossfeed was originally (in the past) something I didn’t like, however nowadays I prefer to listen headphones only with crossfeed. Also, I am not so interested to compare sound qualities by switching between equipment, rather I like to spend time and then get the feeling and impression via longer term sessions. All in all, as this is also top-of-the-line unit, I can’t imagine what other tweaks I would need, even if considering Corda Soul also as a DAC. It has enough inputs and it displays the sample rate. I don’t need DSD, and MQA is already dead to me.

I use mainly MacMini as digital source via Matrix Audio USB bridge and coaxial cable. First tests I did with USB directly from MacMini, and the sound was at least as good, if not better. I prefer to keep a bit isolation in between computer and USB input, but I need to test it out again to be able to say if there is a difference.

Edit: after posting the review, I read older post by Jan explaining the USB input isolation inside Corda Soul. I might later remove the Matrix Audio USB bridge and use the USB input of Corda Soul without additional components.

For vinyl source and analog XLR in the first impressions were not as spectacular as for digital inputs. The sound was at least as good as with my previous preamplifier, and the ”FF black magic” seemed noticeable also in analog. I appreciated the fully balanced design. Nevertheless I need to take more time to play with gains and other system factors.

To sum it up: simply brilliant preamplifier/headphone amplifier! In my viewpoint it provides fantastic value, considering it serves me as a dual-purpose unit. Corda Soul is the best single component upgrade I ever made, after 25+ years in the hi-fi hobby .