ZOTL40 Reference Amplifier
ZOTL40 Reference Amplifier
The latest iteration of LTA's EL34-based amplifier, the ZOTL40 Reference amplifier is an end-game component for guaranteed excellence in any environment.
Reference. It’s that good.
Linear Tube Audio is proud to present the ZOTL40 Reference amplifier. A worthy flagship and the most refined manifestation of David Berning’s ZOTL design.
The latest iteration of LTA's EL34-based amplifier, the ZOTL40 Reference includes a new chassis, component improvements, and is supplied with Mullard NOS EL-34s that take this 50 watt-per-channel amp to a new level.
Curated to be the best
Careful component auditioning with a broad range of available loudspeakers elevate the ZOTL40 Reference amp to deliver the best results possible in a wide range of systems.
The best tubes on the planet
EL34 tubes are rightly revered for their tight bass, velvet mids, and smooth highs that allow for hours of listening without fatigue. The ZOTL40 ships with a matched quad of the best Mullard EL34 tubes on earth.
Listening is the only way to improve an audio product, which is why we take customer feedback so seriously. We have some of the most knowledgeable and discerning customers in the industry, and their input is a key part of our product development process. The ZOTL40 reference amp is the kind of unbelievably good product that can only be achieved with careful development and experimentation over time.
Tube tone + solid state detail
Traditional tube amps are known for their liquidity and linearity, but their “warmth” masks details and can sound thick. Solid state amplifiers give you that detail, but can be “clinical.” ZOTL amplifiers give you the best of both worlds: beautiful tube tone with the clarity of solid state (while being entirely tube-based.)
Looks as good as it sounds
The low-resonance aluminum chassis of the ZOTL40 Reference is designed and manufactured in Richmond, Virginia, by the award-winning industrial design crew at Fern & Roby. Sturdy toggle switches and machined aluminum front and rear panels exude quality.
The ZOTL40 Reference amplifier is based on David Berning’s patented ZOTL technology, the only advance in tube technology since the 1950’s. For a technology to be patented, it must be deemed “new, useful, and non-obvious.” We think that sums up our approach quite nicely.
Premium components = premium sound
If you use cheap, generic parts, guess what kind of sound you’ll get? That’s why we use only premium, name-brand components. Belleson regulators. Ohno OCC wiring. Vishay Dale resistors. Mundorf caps. Typically, these are names you’ll only hear in amps that cost $10k or more.
Never buy another set of tubes
Most tube amplifiers run through tubes every 1,000-2,000 hours. That sounds like a lot until you consider that we estimate tube life for our amps to be in the 10,000-20,000 hour range. Why? Because we use ⅓ the current through the tubes, which results in lower heat and dramatically longer tube life.
Made in the USA
Every LTA product is designed and built by hand in Takoma Park, Maryland, by a group of technicians who are also musicians, audiophiles, and music lovers. Some of whom have been with us since the company’s earliest days.
The ZOTL40 Reference amplifier is hand built by technicians with years of experience building the complex ZOTL circuits. All our products are backed by a 2-year warranty and a 14-day no-questions-asked return policy.
Reviews & Testimonials
Staging is layered, dimensional, and expressive; with a noticeable ability to render a sonic presentation of venue / studio space. Bass is tangible, tonally accomplished, and powerfully deep. Treble is very good, with a complete lack of grit or glare. Midrange is delightfully musical, and realistic. Tone is uniformly excellent throughout the frequency spectrum. This amp plays any type of music with an unconstrained ease, and can be listened to for hours on end without fatigue. While the convincing three dimensional staging, and densely rendered imaging are fabulous, in my opinion, it is its flowing musicality that is the Z40's true star-turn.
LTA amplifier owners have found great enjoyment using their amps with a variety of speakers outside of the below ranges. The below are guidelines, not rules.
Critical listening environments: 85db sensitivity and above
Smaller rooms / lower volume levels / non-critical listening: 80db sensitivity and above
If you have questions about your specific speakers, chances are someone we know has tried them. Don’t hesitate to reach out with questions about your specific setup. Also, don’t forget we have a 14-day no-questions-asked return policy.
What’s New in the ZOTL40 Reference Amplifier
We have been making the ZOTL40 (Mk II) for a couple years, and it enjoys a stellar reputation when using low sensitivity speakers such as electrostatics. Over the past year LTA has invested in design development and along the way found opportunities to bring fresh insights and refinements into every one of the products in our lineup, including the ZOTL40 reference power amplifier.
The ZOTL40 reference amp is the kind of unbelievably good product that can only be developed with careful experimentation over time.
Improvements in the ZOTL40 Reference amplifier include:
Careful component auditioning (review & final selection) with a broad range of available loudspeakers to elevate the ZOTL40 reference amp to deliver the best results possible for our clientele.
Premium Mullard EL-34 tubes are standard.
New chassis designed and built by Fern & Roby includes careful selection of materials and finishes plus grounding and shielding improvements.
The result is a significant improvement to the ZOTL40 Mk II that makes the ZOTL40 Reference an end-game component for guaranteed excellence in any presentation.
Purchase without fear or doubt. Like all Linear Tube Audio products, the ZOTL40 Reference Amplifier comes with a 14-day no-questions-asked return period and a two-year warranty.
We also have the ZOTL40 Reference available with a few additional options, including the old-style case, KT77 tubes, and a custom front-plate. See the ZOTL40 Reference options page for details and pricing.
Sensitivity: 1.2V provides full output
Output impedance: 1.6 ohms
Input impedance: 50k
100V / 120V / 240V operation: Auto-switching
Hum and noise: 94dB below full output (measured between 8Hz-60kHz +0/-0.5dB)
Power output with 4-ohm load: up to 51W, 0.5% THD
Power output with 8-ohm load: up to 46W, 0.5% THD
Frequency response (8-ohm load): 8Hz to 50kHz, +0, -.5dB
Amplifier class: Push-pull Class AB
Net weight: 15 lbs
Dimensions: 17 inches (43 cm) wide, 5 inches (12.7 cm) tall, 13.875 inches (35.2 cm) deep
Finish: Aluminum case
Tube complement: two 12AX7s, two 12AU7s, & four Mullard NOS EL-34s - No adjustments – tubes are auto-biased
For those who demand the best, but want to keep things simple. The Z10 Integrated amplifier delivers the magic, realism, and 3D soundstage of our patented ZOTL technology, all in one (gorgeous) box.
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The ZOTL Ultralinear is the latest amplifier design by David Berning: the first ultralinear amplifier not limited by traditional output transformers.
The next generation of the ZOTL10, the Mk.II, has a beefy linear power supply. Designed with ultra-low noise Belleson regulators, the transformer is in a separate enclosure in order to ensure the lowest noise floor possible.