Current not voltage gain? Modern preamps tend to 'see' a semi-standardized stable 47'000Ω amplifier input, not the moving 1-50Ω target which speakers can traverse in the real not nominal world. With voltage gain no longer an issue when digital sources deliver from 2-8Vrms yet most amps reach full output at less than 1V, there's still current gain. The Pass HPA-1 headphone amp happens to make for a terrific if minimalist preamp. As Indian designer Jam Somasundram working for Pass Labs on his first assignment explained, that's likely due to it having been engineered as a small power amplifier. That explanation resurfaced as I tried to make sense of the changes the XP-12 first caused when it replaced our customary Wyred4Sound STP-SE II during a review of the Polish MySound Cube monos.

Wayne's championed Toshiba field-effect transistors in complimentary p- and n-channel flavors.

At 12 watts in p/p class A EL84 pentode, the Polskie monos are low power like paralleled 2A3 or standard 300BXLS SET. Just so, on bass amplitude into copasetic loads like Kroma Audio's 92dB Mimí or Living Voice's 94dB R25A, they actually outdid our 200-watt LinnenberG lateral Exicon Mosfets. Where they landed second was on ultimate bass reach and particularly bass control.

Soundaware D300Ref SD card transport ⇒ I²S via HDMI ⇒ Denafrips Terminator ⇒  XP-12 ⇒  MySound Cube ⇒ Kroma Mimí, no sub. Chai the Bengal hogging some rare sun spots on the carpet.

The XP-12 intercepted those looser bloomier bass textures, tightened them up and dropped reach exactly as you'd expect and should get from a more powerful amplifier. The behaviour was as though the amplifier portion of the pre had relocated to bolt itself to the tube monos and make those bigger.

In concert with its stablemate XA-30.8 amplifier, I exploited the same bottom-up and control virtues to play up a 9" 1st-order two-way maxi monitor's midband-out voicing. The preceding Pass components underlined a centering of the tonal balance in the heart land of a cello or lower male voice as the opposite to a maximally lit-up presentation from the top down. Without yet focusing on the XP-12 per se, just noticing its contributions in the context of parallel reviews, I'd already connected with key observations in Dawid's assessment.

iMac music server ⇒  USB ⇒ Soundaware D300Ref bridge ⇒ I²S via HDMI ⇒ Jay's Audio DAC-2 SE ⇒  XP-12 ⇒  Pass Labs XA-30.8 ⇒ Lu Kang Audio Spoey230, no sub.

For a specific music example, cue up "Gold Dust Bacchanalia" on the Mychael Danna soundtrack to Myra Nair's Kamasutra movie. Crank up the volume. Pay attention to the true infrasonic content of the hit at 0:40, then listen closely to what happens an octave below the jagged bass line starting at 1:05. Making sense of and distinguishing that takes a full-range system. Yet that precisely was the extra the XP-12 provided right off the bat.


Granted, Mr. Danna mixed in some very low stuff which doesn't usually appear in regular music. But then high-end hifi is about having you all set for the totality of possible musical encounters. And on excavating the abyss when apparently high preamp current met even higher amplifier current from 20 always-on transistors per channel, the Pass duo really went down the mine shaft.