ZESTO AUDIO ANDROS TÉSSERA REFERENCE - PHONO STAGE

Key Features For A Quieter and More Musical Phonostage

Musical Features

• Completely new 100% tube analog circuit design with optimized components.
• Dynamic range increased from 108dBV to 116dBV, so the quietest parts are quieter, louder parts are louder.
• Loading on the secondary of the MC transformer to capture the most detail from the cartridge.
• 12 position MC load per channel with more finessed adjustable options like 1000, 800, 700, 500, 400, 350, 300, 250, 200, 150, 100, 50 Ohms
• Two completely independent dual mono channels, with LED indicators for A and B
• Gain is improved up to 7dB, which increases the output volume to better match your cartridge to your system.
• The voltage increases from 250V to 300V for more headroom.
• The power increases from 52W to 60W to provide more energy needed to reproduce the highs and lows of music accurately.
• The amps increase from 3.4 A to 8 A to provide more current to the tubes.
• Maximum output improved from 8V RMS to 12V RMS increases the headroom to allow more musical peaks like trumpet and drums.

Quieter Features

• New 12DW7 tubes improves the amplification to better drive the output tubes which gives you lower noise, more headroom and lower distortion.
• Dual chassis external power supply
• New Toroid design ESP Supply replaces the linear regulated power supply which generates significantly less noise by concentrating the magnetic fields.
• The dark black noise levels went from -90dB to -95dB.
• New PCB layout with significantly more grounding for lower noise.
• Dual chassis with 3-meter RFI filtered umbilical cable to eliminate external noise.
• Dedicated output tubes driving high quality output transformers to create a true differential low impedance output for lower noise and ideal transfer of power to the preamp.
• True floating ground, transformer balanced XLR inputs and outputs
• New grounding throughout to further reduce the internal and external noise.
• Switching on relays so there’s no digital chatter.
• Easily adjustable MC “Load on the fly” without klicks or pops so you can hear the change
• Elegantly designed 16-gauge steel enclosure to help isolate the electronic “chatter” from nearby equipment
• Ground lift switches on the MC inputs on each channel to prevent noisy ground loops
• All the RCA and XLR connectors are Gold plated for better conductance and lower corrosion

Other Features

• Accommodates 4 tonearms, 1 MM and 1 MC per channel
• All settings are saved when you switch between channels
• More energy efficient Standby power that reduces the drain from 7w to 0.5W.
• All switches and knobs are easily accessible, nothing hidden inside to adjust
• Recessed RCA connectors are durable and will hold up to the typical Audiophile who loves to change their configuration
• Each unit is hand built “Made in the USA”
• 50-hour factory burn in on all circuits and vacuum tubes before final testing

Tessera means the number 4 in Greek

Specifications:

Inputs per Channel

• Two completely independent dual mono channels, A and B with LED indicator
• Accommodates 4 tonearms, 2 per channel
• Separate MM and MC inputs per channel
• Each channel has independent controls and all selections are saved when you switch between channels
• Selection switch for MC and 2 position MM 47K and MM 68K
• MM impedance switch 47K or 68K Ohms
• MM capacitance 220pf
• MC transformer Balanced gold plated XLR input
• MM and MC Single Ended RCA input, gold plated with isolated ground
• 4 MC ground on/off switch
• 12 position MC load impedance:1000, 800, 700, 500, 400, 350, 300, 250, 200, 150, 100, 50 Ohms
• 4 Superior quality MC Internal step up transformers
• 3 position MC gain switch for High, Medium & Low output cartridges
• Two ground binding posts

Outputs per channel

• High quality output transformers driven by dedicated 12AU7/ECC82 output tubes
• True floating ground, transformer Balanced XLR gold plated outputs
• Single Ended gold plated RCA output, with isolated ground
• Impedance 600 Ohms
• +12V max output level

Active Components

• Two (2) Gold pin JJ ECC83S/12AX7 vacuum tubes with high quality gold pin ceramic sockets
• Two (2) JJ ECC832/12DW7 vacuum tubes with high quality gold pin ceramic sockets
• Two (2) Gold pin JJ ECC82/12AU7 vacuum tubes with high quality gold pin ceramic sockets

Power

• Dual chassis
• Power supply with 3 meter DC umbilical cable incorporating special RFI suppression
• Locking bayonet connector rated for higher voltage and higher current
• New ESP Supply with 3 Toroid. 1 high voltage 300V and 1 low voltage 12V low power and 1 low voltage 12V high power, housed in the external unit.
• Power supply dual color LED, yellow for standby and red for ON
• Main unit push ON/OFF front power switch illuminates a red LED on Channel A or B
• Power supply standby switch on the front
• Power supply standby power rating 0.5 Watts
• Power consumption 60 Watts
• Standard 3 pin 15A IEC power connector on power supply
• Voltage 110V – 120V AC 60Hz
• Optional factory installed 220V – 240V AC 50/60Hz

Detailed Specifications

• 3 position Gain switch
• MC input 65dB, 70dB and 75dB or MM input 47dB, 51dB and 55dB
• Noise  95 dBV below max output level
• Dynamic range 116 dBV
• Frequency response complies with the original RIAA curve within +or- 0.5 dB
• RIAA curve is achieved using a passive filter
• 1% metal film resisters throughout
• Polypropylene capacitors throughout the audio path
• All analog tube circuitry with no solid state devices in the signal path

Other Features

• Controls on the front
• “Made in the USA” using US and imported parts
• Each unit is built by hand
• 50 hour factory burn in on all circuits and vacuum tubes
• Dimensions main chassis 17″ W X 15″ D X 5.5″ H, Power Supply 17”W x 8”D x 5”H
• Weight: Main unit 27 lbs. (12.25 Kg), Power supply 18 lbs. (8.16 Kg)
• Shipping weight 55 lbs.(24.9 Kg), box 20″ X 20″ X 16″
• 16 gauge zinc plated steel enclosure
• Two year limited warranty
• Six months warranty on Vacuum Tubes