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. As an option you can choose a transformer balanced input and also select a HQ mains power cable.
Prices in Euro incl. vat excl. freight:
Transformer balanced input
High Quality Puritan Audio Laboratories mains cable 1 meter
High Quality Puritan Audio Laboratories mains cable 1,5 meter
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 supply user-switchable between 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)
A couple of reviews & videos:
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. 2019 Positive Feedback Writers’ Choice Award