Greetings! Up for your consideration is a nearly new (purchased in June 2018), very gently used Linear Tube Audio/David Berning MicroZotl MZ2 Tube Headphone/Preamp/Amp. It doesn't have any blemish's that I can see. It has the following upgrades:
--upgraded LPS+ Linear Power Supply
--1/4 inch Headphone jack
--4' upgraded cable to connect the LPS to the preamp
--3' Audio Archon Blue (Furutech) Power Cable with upgraded Rhodium/Carbon Fibre Plugs ($250 value)
--NOS 12sn7 tube upgrade (200 hours total)
--Remote control (uses apple remote, which is included and new in the box)
--Original shipping box (custom fitted for the MZ2)
The total retail value of this is $2,290 plus the $250 power cable for a retail value of $2,540. I will include shipping and PayPal if i get my asking price. See info from LTA's website:
The successor to David Berning's original micro-ZOTL, the MZ2 continues to offer what Berning intended it to: an introduction to ZOTL technology.
Equally a headphone amplifier, integrated amplifier, and preamp, the MZ2 is considered reference-grade for powering almost any headphone, as a 1 wpc amp for extremely efficient speakers, and as a preamp performing well above its price.
Hand-built by our small team just outside of Washington, DC, each MZ2 involves 12 hours of delicate work, including precise hand-winding of several proprietary components, and several days of burn-in and testing.
While technically an OTL amplifier, not having traditional output transformers, the MZ2 is an entirely different kind of circuit that is able to achieve low output impedance and low-current tube operation, which translates to easy matching to almost any headphone or speaker and a very long tube life. ZOTL technology results in amps with the transparency of OTL without the many limitations of OTL designs: purely tube amplification that achieves a theoretically ideal turns ratio and happily interacts with speakers from 2 to 16 ohms, or above. Headphones from 16 to 600 ohms are powered without any hum.
A new feature of the MZ2 is an on-board jumper that allows the user to switch between using 6SN7 and 12SN7 tubes.
We also now offer premium DC cables for the connection between the amp and the power supply. Visit the cables section of the shop to purchase.
NOS tube option - the MZ2 comes standard with Russian Tung-sol (new production) 6SN7s and 12AT7s. In the 50's, automobiles changed the electrical systems from 6V to 12V, so to support the car radio market, all the tube manufacturers came out with 12V tubes. They sound identical to 6V tubes, but few amplifier manufacturers are aware of them. The good news is you can get a 12SN7 that sounds the same as a $150 each 6SN7 for a fraction of the cost. The MZ2 can use either 6SN7s (6 volt heater) or 12SN7s (12 volt heater). You can get the biggest sonic upgrade to the microZOTL with the $60 NOS tube option that provides 2 tested, noiseless 12SN7s installed in your unit. No hassle. Why wouldn't everyone want this? Some people have shoe boxes full of NOS 6SN7s and get no advantage with 12SN7s. (Note we charge the difference in cost, so NOS upgrades do not also get the Russian 6SN7s...you would never listen to them anyway once you had the NOS tubes).
LPS Linear Power Supply - the original microZOTL has a switching power supply, which comes with a basic unit. It's low cost allows the MZ2 to be available at a very low price. But the linear supply (LPS) is a much better supply utilizing super low ESR caps and a super low noise Belleson regulator. You get better sonics with more dynamics. Not as big of an upgrade as the NOS tubes, but easily discernible sonic improvements.
Remote Control - the MZ2 remote uses a motorized version of the Alps Blue Velvet pot, which is also used in the non-remote version. Same pot, so same sound. No sonic signal degradation. It uses the Apple TV remote control. It is paired to the unit and controls volume only.
Premium DC Cable - the MZ2 comes with an umbilical cable that connects the amplifier with its external power supply using locking jacks. Purists can upgrade to a higher quality wire which provides a detectable, yet less noticeable sonic improvement.
Dual Preamp Outputs - some users desire dual preamp outputs and no speaker binding post outputs. This option is no charge when ordering an amplifier. Please email us your desire for this option just after ordering your amplifier.
Tall Tube Cover - this is an optional clear cover for the MZ2 with two 1.5 inch holes above the power tubes to allow for alternative tube types that are either on adapters or are taller than standard 6SN7s and 12SN7s.
Designed by David Berning - one of the world’s premier amplifier designers
Hand-made just outside Washington, DC
External power supply - extremely low noise floor
Drive high efficiency speakers (95db efficiency or higher) to adequate volume.
Universal voltage power supply or high quality linear power supply
3 selectable inputs
Class A preamplifier output
Transformer-less design eliminates intermodulation distortion inherent in all transformer designs
Simulates the correct transformer turns ratio using impedance converter
Low impedance output easily matches wide range of headphones and speakers
No heavy power or audio transformers
Optimized tube life expectancy of 10 - 20 years based on use
One year warranty including tubes (international pays shipping)
Amplifier class: Push-pull Class A, no feedback
Sensitivity: 0.6V RMS [full output]
Output impedance: (measured @ 0.5A, 60 Hz) 2 ohms
Input impedance: 50k
Power Supply Input: Auto-switching 100V / 120V / 220 / 240V operation or linear supply user-switchable between 110/120 and 220/240 (contact us if in need of a 100V linear supply)
Power Supply Output: 12VDC 2.5 amps
Hum and noise: minimum 60mV RMS or 90dB below full output (20Hz-20kHz)
Power consumption from ac power source: 33W
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
Size: amp: 9 1/2 inches (24.1 cm)wide, 4 3/4 inches (12.0 cm) tall, 7 7/8 inches (19.7 cm) deep (including connectors)
linear power supply: 12" (30.48 cm) x 3.25" (8.26 cm) x 4.25" (10.8 cm)
Net weight: with switching supply: 5.35 lbs (2.5 kg) - amplifier and external power supply)
with linear supply: 8.94 lbs (4.1 kg) - amplifier and external power supply)
Finish: Aluminum case w/ lexan top
Tube complement per channel: 12AT7/6201 input, 6SN7 or 12SN7 output