When Dan's care package arrived, it contained unexpected bulbs – Elrog ER50 and original Western Electric 300B. Like they had for me, shop.best300b had been unresponsive to his KR 4A3 inquiry even though he'd prepaid. So neither of us had any. I had to look up ER50 specs to learn that it will actually take up to 7.5V on the filament. The L2 would only run it at 5V. I'd think of it as perhaps a Super 45.

With Vinnie's first batch of silver tube covers coming from his supplier with slightly narrower diameter than specified—he'd send me replacements in due time—they didn't fit over the more bulbous WE but cleared the EH and Elrog. I thus ran the WE without covers to no apparent ill effect.

For speakers, I still had on hand the revolutionary widebanders from Voxativ's former chief engineer Oleh Lizohoub who had since revived his former Ukrainian Camerton brand to promote his very different Binom-1 widebanders out of Berlin. Achieving in a fraction of the cubic volume and with a far smaller flat driver what Cube Audio's Nenuphar does in a big quarter-wave floorstander with a 10-inch driver with triple whizzer, I meant to enjoy the compact mind benders at their finest before they were due back.

Sorting through our most likely amp candidates for L2, I ended up with our Nelson Pass XA-30.8 class A hulk ahead of the LinnenberG Liszt, FirstWatt SIT3 and SIT1. The big push/pull stood in for the 50-watt class A Holton Inviso which Camerton had shown with at the alternate Munich show.

I already knew how well Vinnie's XLR4 output drove HifiMan's Susvara. Those flagship planars would thus repeat these exact tube swaps in the next round to hear whether anything about my speaker observations would shift. After all, speaker soundstaging and frequency response from room interactions can be very different to headfi.

iMac ⇐ 3TB FusionDrive with music library buffered in 32GB RAM ⇐ Audirvana 3 ⇒ USB reclocked by Soundaware D300Ref ⇒ I²S via HDMI ⇒ Denafrips Terminator ⇒ L2 ⇒ XA-30.8 ⇒ Camerton speakers.

On a classical piece recorded exceptionally well by the Dutch trptk label, of string quartet and woodwind quintet playing symphonic transcriptions, this is what I heard:

• ElectroHarmonix 300B: the texturally/temporally most damped and, by contrast, the energetically most dull, less free and gushing, colors more muted, dynamics more contained
• Elrog 50: temporally freer and more gushing, the most shimmering upper harmonics on strings, oboe and flute, slightly lean but vivacious, microdynamically more agile than the EH
• Western Electric 300B: the most fluid, gushing and texturally liberated, the most dynamically alive, the most burnished colors – the pick of this litter, for this music

Next was righteous funk from George Duke's Dukey Treats disc which I have as a final mix file prior to commercial mastering, hence before it was dynamically squashed for mass consumption. For a faint semblance of it, here's the "Everyday hero" track I used.

Before you balk and bark "Impossible!" because such music isn't part of the traditional 300B repertoire, remember today's context. The Pass Labs amp with its 20 always-on push/pull transistors per channel did the heavy lifting of low-impedance transients, current and power stability. The tubes merely drove its steady high input impedance to coast, blissfully oblivious to what the signal contained.

• ElectroHarmonix 300B: like before – more muted and dull than the other two, dynamically sleepier, lazier on incisiveness and slam, somewhat tame, foggy and civilized
• Elrog 50: quickest and slammiest of the three, with fabulous PRaT and punch, slightly bright on the blatty brasses but vigorously in the pocket  – the pick of this litter, for this music
• Western Electric 300B: very similar to the Elrog but not quite as fast and rhythmically tensioned, tonally a touch fatter to be preferable if the system/speakers lean toward brightness