Stable reference. A reference is what we're used to thus refer to as our status quo. It's no intrinsic mark of special excellence. After 20 years on the job, one simply hopes that any reviewer's system isn't just what they know but also top quality. That's how I feel about our Bakoon AMP-13R. Its patented current-gain circuit with proprietary new instant-on bias controller doesn't use throwaway attenuation. True variable amplification factor only generates the gain desired. As a DC-coupled wide-bandwidth class A/B affair of very low self noise, it's the most resolving most sophisticated transistor amp in our collection. It's how I had put the Z10 in the frame to see it as a quasi Bakoon executed with glowing bits. It's what now gauged the UL to find that on leading-edge edginess, the ultralinear glass had moved a more distinctive tubular softness into the foreground. Devotees of the AMP-13R—the same general sonic aesthetic would include amps from LinnenberG and Soulution—might want to own an option of akin resolution and sophistication that's just different enough to matter. The Z10 would arguably come too close to justify seconds. It's today's version which creates that alternate reality of familiar detail with just enough textural difference to service a separate mood without becoming too altered. In short, it's the very rare valve amp yours truly would own after my wholesale divestiture of more traditional specimens from Art Audio to Octave, Ancient to Trafomatic to Woo.

"I loved the coffee analogy in your Cube Audio Nenuphar Mini review. I'd love to hear the Vinnie Rossi L2 and experience how a world-class tube preamplifier changes our sonic signature. Unfortunately it's out my present budget due to new R&D. Maybe I could try the LTA MZ2 first. The original version was actually on my wish list as a college student years ago. Then I read the 6moons Almarro review and went that path instead. I modified caps here and there, tried different tubes etc and really liked it until I discovered Bakoon." That was Soo In Chae of Bakoon writing in months prior. I'd then replied that "I think Linear Tube Audio are for valves what Bakoon are for transistors. Each is at the top of their respective class."

More on correct softness. For the complete picture, we add that UL's softness means no extra warmth or tonal fat, no dimming of the brilliance region, no wool in the power zone. Versus the AMP-13R in fact, bass over our all-aluminium rear-ported Dutch monitors had more weight and dynamic differentiation. That unexpected trait was easily confirmed with multiple A/B. Unlike comments elsewhere—that the Z10's headfi performance mysteriously differs from its speaker sound—I again heard exactly the same over our HifiMan Susvara as I did over the Acelec speakers. On the hi-gain ¼" jack, Susvara simply hit normal SPL at already 20-something on the goes-to-99 dial unless music was recorded unusually low. UL thus is a properly nuclear option for even the most inefficient of headphones and should be thought of as shorthand for UnLimited.

With recent album discovery 'Filagmena Stin Psihi' by Mimis Plessas & Dimitirs Savvaidis pinned up.

By shifting some emphasis away from the edge of attacks, we might say that UL's pencil swaps from a very hard very pointy to a more soft-nosed tip of softer lead. That new balance, re-weighted a bit deeper into the bloom rather than transient portion of tones, has obvious benefits for speakers and headphones which are exceptionally crisp either due to a forward treble and/or unusually low phase shift and energy storage. Hello archetypal filter-less widebander; hello hyper-dynamic AMT tweeter. I used 'archetypal' because every apparent rule has exceptions. Still, many single-driver speakers have such a clean impulse response and absence of multi-driver time confusion that when even slightly rising amplitude in the 2-6kHz range adds itself, their enunciation can seem a bit affected; as thought an announcer brought to bear too much tongue/tooth action and not enough chesty resonance.