The first sessions to take a pulse happened upstairs in a compact but carefully curated setup. An SD card transport forwarded S/PDIF to the Classic DAC. That fed a Simon Audio integrated. Speakers were aluminium-encased Acelec Model One with Mundorf AMT, ScanSpeak mid/woofer and stacked 1st-order filters. On the tweak front were Avantages Audio omnipolar magnesium super tweeters on a 15kHz/1st-order hi-pass, a Zu Submission subwoofer on a 20Hz low-pass with +6dB/20Hz lift, LessLoss Firewall for Loudspeakers inline filters, Hifistay Stella60 decoupling footers underneath the speaker stands, Avantages Audio Static cables on the integrated and a Puritan Audio Lab PSM156 AC/DC filter/conditioner. Comparator DAC was a JAVS X7-DAC MQA with Clean Power battery/super-cap external supply.

The Nagra was the darker, warmer, smoother, slightly more rounded and dense operator. Leading edges weren't as sharp so separation was mellower. It also moved the soundstage back a bit and hung more connective tissue into inter-image spaces. These traits in toto had a subliminal effect on my perception of pace. The Classic DAC felt more relaxed and a tad slower; like cream in coffee. To get serious with it, I needed an amp of superior resolution and speed. After having tried all our other on-call integrateds, the i5 had best dovetailed with the Korean DAC but wasn't ideal for the Nagra. To keep the sub in the loop, I inserted our Classic preamp for the necessary pre-outs. Then a Bakoon AMP-13R added current gain. Like magic or superior synergy, now things clicked. Suddenly Fröst's chalumeau and the period strings of the Concerto Köln with their more pinched solo cello had the correct timbre even during the Four Seasons-type sautillé sections.

Yes, thinking readers are correct. Vivaldi did not compose for the clarinet. All the concertos on this disc are modern compositions in the Baroque style of the famous Venetian to expand the classical blackwood's repertoire. Rather than play them on a modern clarinet which Vivaldi never heard, Martin Fröst had its chalumeau precursor fitted with modern keys to support higher technical demands. It makes for a very specific tonality which the Classic DAC now playing into a wide-bandwidth DC-coupled class A/B amp with a single complementary pair of lateral Exicon Mosfests nailed. That stood in for Nagra's own Classic Amp.

To mash up more glorious instrumental timbres in an inspired performance by soloists from the Czech Philharmonic under Jakub Hrusa, I cued up Antonin Dvorák's underrated Serenade for winds, cello and double bass in D minor, Op. 44, B 77 and its "Andante con moto". The Nagra positively glowed in this pastoral Brahmsian setting with its intensely autumnal tone colors from these gifted players honoring one of their country's greatest classical composers. If these colors lack saturation or moodiness, it's all for naught but the Classic DAC was truly at home.

For a semi-symphonic Silk Road song with string orchestra and slinky lyrical lead tenor, Elton Hüseyneliyev fit the mood with "Payiz yagisi" from his Azerbaycan album. In such settings, bowed strings are supposed to be sweet and slightly voluptuous. With the Classic DAC, these strings properly were. When Elton's vocals gain octave-doubled lower bass support, the effect was duly electrifying.

Now in a purely instrumental mood, I cued up the Transatlantic Guitar Trio's take on "Caravan" where Joscho Stephan, Richard Smith and Rory Hoffmann trade inspired riffs, playing styles and resultant sounds for a wealth of guitar-based tonal modulations. True to its project brief, Nagra's DAC was very big on tone even without a 6SN7 tube which one might traditionally expect for such a tuning.

To tease out exactly where on the scale it fell, I had to move downstairs and rope in equivalently ambitious DACs for contrast. With these musical choices inspired directly by the Nagra's own behavior, we already know that its core virtues revolved around tone, textures and a certain redolence or lyricism.