Zesto Audio Andros Tessera Reference Phonostage

All-tube phonostage using 12DW7, 12AX7, and 12AU7 tubes, with an external ESP power supply 

After over a year of R&D, Zesto Audio is proud to announce the T-REF as it’s fondly known around their shop. The Andros Téssera Reference Phonostage is a complete internal redesign of the original Téssera. An upgrade path for Téssera is available. Contact us for details.

The challenge was to make it better than the Deluxe, and Zesto is so confident it has succeeded that it did not hesitate to use the “Reference” label. Says Zesto, “It’s quieter, it’s more musical and the detail from the groove is astonishing.”

The Reference features improved dynamic range and ability, higher power and gain, more finessed adjustable options.

The T-REF accomodates four tonearms, allowing one MM and one MC per channel. All settings are saved as you switch between channels, and all adjustments have their own external switches or knobs. There are four superior quality MC step-up transformers, and a three-position switch for high-, medium-, and low-gain cartridges. The high-quality output transformers are driven by dedicated 12AU7/ECC82 output tubes

Every unit is handbuilt right here in California, and there is a 50-hour burn-in on all circuits and vacuum tubes before final testing. 

The T-REF comes with a two-year limited warranty and a six-month warranty on the vacuum tubes.

Reference Upgrades

• New external ESP Supply using three toroids and new circuits
• New tube complement using 12DW7 tubes, as well as, 12AX7 and 12AU7
• New PCB, new circuit design with new optimized components, and new grounding
• Gain increases up to 7 dB
• More power, going from 52 W to 60 W
• Higher voltage, going from 250 V to 300 V
• More efficient standby power that reduces the drain from 7 W to 0.5 W
• Noise levels reduced from -90 dB to -95 dB
• Dynamic range increases from 108 dBV to 116 dBV
• Maximum output improved from 8 V RMS to 12 V RMS

Specifications

MM Specs
Impedance: 47 kOhm or 68 kOhm
Capacitance: 220 pf
Gain (dB): 47, 51, 55

MC Specs
Impedance Settings (Ohm): 1000, 800, 700, 500, 400, 350, 300, 250, 200, 150, 100, 50
Gain (dB): 65, 70, 75

Output Impedance: 600 ohm

Tube Complement: 4 x Gold pin JJ ECC83S/12AX7, 4 x  JJ ECC832/12DW7, 2 x Gold pin JJ ECC82/12AU7

Dimensions (WDH)
Main: 17″ x 15″ x 5.5″
PSU: 17″ x 8″ x 5″

Weight (Main, PSU): 27 lb, 18 lb