microZOTL Preamplifier
microZOTL Preamplifier
The ultimate expression of the microZOTL as a full-featured reference preamplifier and headphone amplifier.
Steve Guttenberg - The Audiophiliac - names the LTA MicroZOTL Preamplifier as his new reference preamp.
microZOTL Preamplifier
After years of refining and testing the microZOTL circuit, LTA has created the microZOTL Preamplifier. This is the highest expression of the patented microZOTL technology as both preamp and headphone amp in a rack-friendly form factor.
The microZOTL Preamplifier has a beautiful new low-resonance aluminum chassis and offers reference-level sonics through upgraded internal components, shorter signal paths, larger power supply, and a digital control system with LED display.
“This preamplifier renders the illusion of real music better than any other linestage I have had in-house for review.”
Level 2 Upgrades
Preamp output cap upgrade: The headphone and the preamp outputs have been separated, and different types of output caps, optimized for each output, are installed. The preamp cap is upgraded to a premium Clarity CMR.
Power supply cap upgrade: The power supply caps and power storage caps on the audio board are changed to Mundorf Mlytic AG capacitors. The total amount of storage is increased by 22,000uF.
Current microZOTL Preamp owners can upgrade to Level 2 and get the 2020 production upgrades via our upgrade program.
Feedback from satisfied Level 2 Upgrade customers:
“A more robust overall sound and smoother finish - better bass response and glossier highs.”
"Details, staging, smoothness, musicality, airiness were all improved. There was more space between the performers and vocals were less recessed and muddy when the music complexity surrounded the voices. It was easier to pick up the different voices when performers were harmonizing."
“More well-defined details."
~Tim H.
It has been a couple of months after getting back the MicroZOTL Preamp upgraded to Level 2. And wow - what an upgrade! Level 2 takes everything good about the Preamp and makes it better. More bass, a touch more resolution, more air on top, and with that more dimension and liquidity to the music. A preamp is the heart of a system and Level 2 places the unit in rarefied air as one of the highest performing preamps I've heard (and the original was no slouch). In addition, the upgrades to different gain amounts and more steps on volume control are nice additions to functionality. Really, if anyone is hesitating about the upgrade they should just do it - it is almost like getting a new component, although the basic sound signature is unchanged. Kudos to LTA.
~Bill O.
Balanced Input Transformer Upgrade
The balanced input transformer upgrade adds high-quality Lundahl input transformers to the XLR inputs on your microZOTL Preamp. If you have a source with balanced outputs, this upgrade retains all the sonic fidelity of your source and is a worthy upgrade.
Production Updates for 2020
We’ve recently made a few changes to all new production units that make incremental, but important, sonic improvements. The best part? The price remains the same.
Power transformer upgrade: The power transformer is upgraded to a larger custom transformer with multiple windings to improve isolation, which results in lower noise.
Coupling cap upgrade: The six coupling caps on the audio board between the tube stages are upgraded to premium Japanese film caps with gold plated OCC leads.
Updated volume control w/ gain adjustment and “Hi-Res” setting: The new 8-bit volume control gives you 128dB of total attenuation via 100 individual steps. “Hi-Res” increases this to 199 steps for finer level control. In addition, three gain control options are available: 0dB (default), -15dB, and -30dB. This adjusts the volume level to allow for finer low-level attenuation when using sensitive speakers or headphones.
Current microZOTL Preamp owners can upgrade to Level 2 and get the 2020 production upgrades via our upgrade program.
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.)
Sonic improvements at every level
New circuit board material, new volume control technology, upgrades in wire, capacitors, tubes, linear power supply. The microZOTL Preamplifier is the clearest, cleanest sounding microZOTL yet.
“Yeah, it’s a really, really good preamp.”
Looks as good as it sounds
The low-resonance aluminum chassis of the microZOTL Preamplifier is designed in Richmond, Virginia, by the award-winning industrial design crew at Fern & Roby. Brass touch buttons, LED display, and machined aluminum front and rear panels exude quality.
Patented perfection
The microZOTL Preamplifier 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. Vishay Dale resistors. Mundorf caps. Typically, these are names you’ll only hear in amps that cost $10k or more.
“The MicroZOTL Preamplifier produced a spatial perspective that made my seven foot tall 21 driver speakers completely vanish in the largest and accurately layered soundstage that I have ever experienced in my listening room.”
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.
Quality assurance
The microZOTL Preamplifier is hand built by technicians with years of experience building the complex ZOTL circuits. All our products are backed by a 3-year warranty and a 14-day no-questions-asked return policy.
Reviews & Testimonials
MicroZOTL Preamp Owner Edwin C.
Sonically, I was first struck by the huge, wonderfully LAYERED soundstage – just WOW. Second, it sounds more like live music than my other preamps – it has a lit, effervescent vibe, yet still manages a fair bit of smoothness. I have more high frequency energy than before, but the sound is not bright per se, and bass is far more controlled than with my previous preamps.
Love by a Thousand Kisses
The LTA Microzotl preamplifier is an easy Writer's Choice. It sounds fabulous, and in my system, the MZ was without a noticeable weakness. Encased in a beautiful Fern & Roby skin, the Microzotl features a well executed design, excellent controls, and a great headphone amp. It is a center-field shot to the parking lot, home run. The MZ is a high-end preamp for those without Ferrari budgets. As soon as I packed it up, I was already missing it.
Positive Feedback by Gary Beard
The Microzotl is a really good preamp. It is an open window of transparency; with fast transient performance, excellent drive, and a high level of dynamic swing. It has a quiet black background, lacks obvious coloration, and is coherent to the point of being dang near unflappable.
The MZ's Vishay Dale resistor stepped volume control is excellent. Noiseless, and transparent. Its taper is well set to give good control at the low end of the volume spectrum; and as such, the MZ excels at both high volume, and low volume listening.
Yeah, it's a really, really good preamp.
Home Theater Review by Terry London:
I still have a sense of being astounded at the level of improvement it renders in my system. The MicroZOTL Preamplifier has a beautiful chassis, great ergonomics, and a comprehensive set of input and outputs. Most importantly, this preamplifier provides rich organic timbres/colors, a sense of "aliveness" that I find in no other preamplifier, the smallest details easily heard, a spatial perspective that brings the musicians into your acoustic space, a sense of holographic imaging, and an effortless liquidity that lets the music spill into your room. I will be purchasing the MicroZOTL Preamplifier, which has surpassed my expectations, and it will be replacing its older sibling in my reference system.
Audiogon User Greg:
“I’m running the new preamp (S/N 005) with my XA30.8. The combination is flat out beautiful. I also have an MZ2 which worked well, but the new pre is just better in every way. Clarity, staging, dynamics (both micro and macro). Very liquid, fatigue free, but also dynamic and extended.
“. . . the beautiful chassis, the ergonomics, and that sound, rich organic timbres/colors, a sense of “aliveness” that I find in no other preamplifier, the smallest details easily heard, a spatial perspective that brings the musicians into your acoustic space, a sense of holographic imaging, and an effortless liquidity that lets the music “spill” into your room.
“. . . micro-details were clearer and were easier to hear all delivered with an overall liquidity and effortlessness that let the music flow into my room.
“. . . the MicroZOTL Preamplifier produced a spatial perspective that made my seven foot tall 21 driver speakers completely vanish in the largest and accurately layered soundstage that I have ever experienced in my listening room.”
Audiogon Review, by Terry London:
“Across every sonic attribute: timbres/color, image palpability/density, spatial qualities- air around players- tremendous soundstage depth/width/height, powerful overall dynamics, and deep extension with great low frequencies regarding tone/accuracy which gives a great foundation to the music. All this and delivered with total liquidity and ease. This preamplifier renders the illusion of real music better then any other linestage I have had in-house for review.”
SPECIFICATIONS
Inputs: 4 Stereo RCA single ended inputs using high quality Cardas connectors; 1 XLR single ended input, with transformer-coupled balanced option with Lundahl transformers. Sealed, silver contact relays utilized in a short signal path. One additional Tape input.
Outputs: Headphone ¼” Phone jack, dual Cardas RCA single ended preamplifier outputs, and a Tape Monitor output utilizing Cardas RCAs (input level before volume control).
Amplifier class: Push-pull Class A, no feedback
Sensitivity: 0.6V RMS [full output]
Output impedance: (measured @ 0.5A, 60 Hz) 2 ohms for headphone outputs, 50 ohms for preamplifier outputs
Input impedance: 50k
Volume Control: Stepped attenuator constructed of 1025 steps of 50 ohms, with 100 positions selected to provide very fine resolution at the lowest volumes and a logarithmic control for higher volumes . Low noise, precision 1% Vishay Dale resistors and hermetically sealed silver contact relays are used for precise, isolated analog signal attenuation
Balance Control: 100% channel isolation using stored differences of volume values. Maximum balance differential is 16 steps
Power Supply: Linear power supply available in 110/120 and 220/240 (100V linear supply available for Japan). Uses dual banks of organic poly ultra low ESR capacitors (4 times MZ2) and premium Nichicon electrolytic for over 100Kuf of output choke isolated storage. Oversize transformer secured with aluminum and brass mountings (no steel). Regulation is performed using low noise Belleson super regulators. Current transformer controls output protection circuit
Hum and noise: minimum 60mV RMS or 90dB below full output (20Hz-20kHz)
Power consumption from ac power source: approx. 50W
Power output: with 4-ohm load: 1W, 1% THD, with 14-ohm load: 0.5W, 1% THD
Channel separation: (4-ohm loads) 46dB, 100Hz-10kHz, (14-ohm loads): 54 dB, 100Hz-10kHz
Frequency response full power: (4-ohm load) +0, -1dB 10Hz-20kHz, (14-ohm load): +0, -1dB 5Hz-50kHz,
Voltage gain: (4-ohm load): 10.3dB, (14-ohm load): 12.4dB
Front Panel Control: Functions include volume, input select, headphone/speaker output select, all configuration menu selections, and amplifier power on-off. Capacitive brass touch buttons are utilized for menu control, input selection, tape monitor control and power on-off.
Remote Control: All functions, including Mute and the configuration menu, are available from the remote, except power on-off. Uses an Apple TV remote. The remote is registered to unit to limit control from unintended remotes. The Right-Left buttons can be configured as balance controls.
Auto-save Features: Volume level per input is automatically saved and the unit powers on using the stored volume levels. Balance and all other configuration menu selections are all saved as a global level across all inputs.
Display Controls: 16 levels of brightness and on-off selectable 7 second timeout
Home Theater Mode: an input can be selected from configuration menu to set one of the inputs to a high-volume level fixed input to allow surround sound device control the volume level
Front Panel Power Switch Override: power switch on front panel can be configured to be set to always on to allow external on-off control for device such as remote-controlled power conditioner
Tube complement: 2 premium hand selected 12AT7 input tubes, and two premium hand selected 12SN7 output tubes. (6SN7s can be used with jumper settings) 12AU7s are often substituted for the 12AT7s to lower the gain if higher headphone output is not required.
Size: 17 inches (43.2 cm) wide, 4.2 inches (10.7 cm) tall, 12.4 inches (31.5 cm) deep (including knob and connectors)
Net weight: 14 lbs. (6.35 kg.) Shipping weight: 22 lbs. (10 kg)
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