But first, a powwow. Must one throw 100 watts at these? How little will be enough? With a 50wpc amp also from Simon Lee on hand, experienced readers know. Off the same front end via the AIO's pre-outs, that would play just 3 decibels less loud. And so it was. Adjust attenuator by a few clicks. Done and dusted. $1'200 when new. Next I relocated to what for the strapping lads at Raal must have been fit only for the faint and feeble.
I set up our €6'000 luxo-but-li'l 15wpc/8Ω current-mode Bakoon AMP-12R. 100 watts had rung the AIO's volume register at 35. Now it said 53. Dyslexia. Otherwise, no early signs of brain damage or audible stress to suggest valid reasons for concern. It's when I cued up Mercan Dede with massive real and synth drums at stout SPL that certain fluttering noises crept in to signal a form of distortion. On those punishing bass transients drawing far higher instantaneous current, I was suddenly starving the ribbons for power. As long as I avoided such fare, thus no action-movie soundtracks with submarine torpedo launches, volcanic eruptions and slo-mo explosion carnage, the Bakoon borderline case was fine for my more careful needs. Wuss badge earned. The lesson here was of good power headroom necessary for the current draw of big low bass attacks, not for desired SPL.
With that handled, it was time to sample various amps now purely on sonic flavour.
Until now, my only disagreement with the SR1a had been that due to its most liberated extension, incisiveness, speed and dynamics from the upper midband on up, it could register as bright particularly past a personal loudness threshold. I thus suspected that our ultra-bandwidth DC-coupled amps of Crayon CFA-1.2 and LinnenberG Liszt wouldn't be favourites. Check. Now I knew with certainty that our class D nCore amps would rate even lower. Check mate. Personal bliss instead lay with hot-running class A and a Pass Labs XA-30.8 with its 20 transistors per channel. Rated at a deceptively low 30wpc, it actually does a full 90 before hitting just 1% THD. With the same tolerance, that's 140wpc into 4Ω.
Without getting poncy on a tube DAC—I used COS Engineering's D1 to double as preamp with analog volume—this earthy darker bottom-up behemoth of an amplifier eliminated my lone disagreement within one track. Be it hard-hitting electronica, purist Baroque, Bruckner's 9th or soprano Sœur Marie Keyrouz singing Byzantine and Melechite hymns from the Greek-Orthodox repertoire, what behaved like a minor axial tilt (more bass, less treble) plus a fuller harmonic envelope transformed my opinion from "ultimate headphone microscope" to "the perfect anytime anything earspeaker".
Top and back headbands plus temple pad removed.
This requires an explanation. I differentiate between listening for and listening to. The former is my analytical reviewer mode. The latter is about letting go to shift into the zone. I'm certain that our readers have their own versions. You know just what performance aspects have you gravitate to this or that mode. Ideally, one enters either at will regardless of the hardware. Personally, a given overall voicing triggers one or the other. Shifting from a spontaneous merger to observational view just requires stepping out and back to have sufficient distance for looking. I find the other direction rather more difficult when a system's tuning triggers my analytical 'mind hearing' and I want to get into the heart space. The precise mechanics should differ with each individual. Suffice it to say that with the COS driving the Pass balanced for minimalist source seasoning, it was the amplifier's qualities which dominated. They set the SR1a's course. Now I started each track in automatic listening-to mode. The takeaway here is that amplifier quality is paramount. What you might think of as only middling amplifier differences due to how they fare with standard loudspeakers of significantly lower resolution will become far more significant with these ribbons.
Temple pad and main head strap removed. Those holes have it.