Zee other tube logic. I used to own valve amps. I no longer do. I still do glowing bits inside preamplifiers from Vinnie Rossi (direct-coupled direct-heated power triodes) and Nagra (small-signal twin triodes). That tells you something relevant about my biases. In a line stage, tubes don't drive reactive low-impedance loudspeakers. They only see the stable high input impedance of your amplifier. They focus on voltage not current gain. They coast not sweat. Once you hear—or better, once I heard—direct-coupled wide-bandwidth class AB transistor amps like our 200-watt LinnenberG Liszt monos, our Bakoon AMP-13R for just 25wpc and Crayon's 68wpc CFA-1.2 in the middle, the clearly lower speed and bandwidth of transformer-coupled valve amps just becomes unattractive. It manifests as general opacity with a softer less informative treble. It means poorer bass control and extension. It means a fat-cat midrange, minor or not so minor fuzz clinging to images and curtailed separation thus lower insight down into complex mixes. Worst for me, it all adds up to an overall energetic reluctance or drag which opposes the sense of unfettered musical gush factor.
Given my friendship with Dan who over a few decades has gone through more than 50 valve amps with often very exotic tubes, I've had a chance to hear some very upscale rarities. The amp Dan still uses today is the VT52 Siegfried where he finds that "Russian 1578 are significantly better than any 6SN7". The other amps are parked in his collection to serve as reminders of his personal hifi journey. I've thus always thought that the only tube amp my current tastes would still enjoy, possibly even favor over transistors if I had the right speakers, would be a Berning. Another chap who feels the same is Chris Sommovigo of Black Cat Cable. The only amp he told me he'd never sell is his Berning. With the Z10, the question of what preamp to mate has been answered by the designer himself. That assures us that the final sound represents the sound he had in mind for his unique output stage. Call it optimization inherent to the concept of an integrated amplifier with an active preamp stage.
99 on the dial is the speed limit.
For my Vinnie Rossi L2 Signature preamplifier, I can currently roll between Western Electric 300B and VT52 for vintage bottles, Elrog 300B and ER50 for moderns. I also tried KR 300B and T100. Those are costly boutique options either way. You could replace the Z10's 2 x 7062 drivers, 2 x 7062 regulators in the power supply, 2 x 12AU7 preamp tubes and 4 x EL84 for a fraction of what one pair of these direct-heated jobs sets one back. That makes ownership of the Z10 a far friendlier proposition. In another nod to modernity and attendant expectations, the volume control is a micro-processor-controlled relay-switched resistor ladder with numerical readout.
From Mark Schneider: "Our first product was the microZotl headphone amp, preamp and 1-watt speaker amp, a class A push/pull with a very liquid sound. It's so quiet, you can turn it all the way up and not tell it's on. We sold nearly 1000. We use 12SN7 because they are 1/10th the cost of 6SN7 and sonically identical. We can provide premium tubes at a very reasonable $60. People have replaced their $15K preamps with it. More importantly it allows those less flush with cash to experience the high-end audio experience every day for only a $1'235 investment. We try to balance our commitment to providing affordable high-end audio with staying in biz. Most audio manufacturers mark up their products twice as much as we do so we must sell direct.
"Our second and third products were power amplifiers, the Zotl10 12-watt EL84 push/pull and the 46wpc Zotl40 EL34. The Zotl10 is the most affordable Berning power amp ever offered. Then came an amp for high-efficiency speakers, the 20wpc Ultralinear with a less forward presentation on such speakers. Then came the MZ3 pre/headfi amp with external power supply and the Z10e dedicated electrostatic headphone amplifier. The Z10 integrated, microZotl pre and MZ3 all have what we call 'home theater mode'. Any input can be selected to be a high fixed volume input so you can calibrate your home theater source to the fixed volume and let the source control the amplifier volume."
Obviously using Apple's standard remote to access menu layers for that and the 16 display brightness modes is more involved. With the l/r controls unused unless activated as balance controllers in the menu, the 'menu' button brings up the menu. It and the central 'mute' switch become selectors and the volume up/down commands scroll through the options. The 'play/pause' control becomes the input selector. 'Mute' is shown as 'XX', thus properly rated even for teenagers. Consult the manual for these fussier details. "We have a two-year warranty. Our tubes last so long (10'000+ hours) that we've never yet had to sell a complete new set. We of course replace poorly performing tubes for free. Depending on what's available just then, a full set of 10 tubes would be from $310-$375 curated, tested and matched to a high standard because the Zotl circuit is especially sensitive to noise."
Z10. 10 watts. 10 tubes. Average price per tube? €37.50. Direct-heated triode lovers will feel their spleen turn. What were they thinking? €1'200 just for a pair of output tubes. Less power than the Z10. Big sluggish output transformers. Limited bandwidth. Higher noise. So last century.