I first heard the RSP-AZ9EX with the RSA-EX1000. The effect emphasized the amp's core characteristics which communicated a coherent sonic objective behind the two. Articulation became even clearer and more incisive. This induced a feeling of staccato not only with percussive instruments like piano but strings in both plucked and bowed passages. Decays were slightly shorter in the bass but richer in the treble to produce larger projection and an accent on reverberation. The tone of acoustic instruments was even easier to differentiate although the general aesthetics leaned more toward sobriety and finesse than body and weight. When I moved to my Riviera Labs AIC-10, I immediately noticed that the RSP-AZ9EX effect became even more apparent. The AIC-10 operates in pure class A up to 10W and clips at ~17-18W/8Ω with a zero global feedback circuit and damping factor of 16. That's more than an order of magnitude lower than the RSA-EX1000. Regardless, it drives my 93dB/6Ω Diesis Audio Aura SE open baffles with authority, offering a bold presentation combined with a quasi euphoric although tasteful emphasis on the midrange and upper bass. Overall I'd place it slightly in the warm/dark quadrant within a diagram of sonic neutrality where the RSA-EX1000 would sit closer to the centre. With the RSP-AZ9EX some bass looseness tightened with an increase of rhythmic pulse and lightness of pace. HF energy was more prominent, adding luminosity, breath and unearthing detail previously partially buried within a smoother less distinct harmonic structure. Combining the AIC-10 with the RSP-AZ9EX made the AIC-10 feel easier and quicker although still not as open and fast as the RSA-EX1000.

SPEC's RSA-EX1000 product page is headed under "the elegant realistic sound". After having hosted the Japanese integrated for the last three months, I cannot generate a better one liner myself. Elegance best describes this sonic character as a mix of gentleness, dignified escape from cheap catchy effects and a certain self assurance that intrigued from the first audition and eventually won me over in the longer run. Through elegance, it managed to reconcile otherwise contradictory features such as neutrality and saturation, composure and visceral impact, control and engagement. At its core it remains a very honest amplifier which was intentionally perfected to reveal minute details that may otherwise be obscured by noise; and to preserve tonal integrity with utmost care. It does both excellently well, qualifying as one of the most transparent electronics I've had the chance of trying yet. It offers that cogency which makes you think 'yes, that just sounds right' over and over again regardless of musical genre, complexity or energy level. Add its capacious power reserves, modest heat and energy consumption, substantial yet still manageable size and weight and you have a component that, as its price suggests, deserves to permanently fit into an upper-echelon hifi system.

With the remote's cabled IR receiver box.