Zesto Audio - Leto Ultra II Preamplifier

Design Philosophy

The preamp is the unsung hero of your system. Like a great actor who never seems to be “acting” it does all the work without getting noticed. As an engineer, my goal is to deliver the most pristine signal from your audio sources to your power amps
without coloration.

My own setup features lots of audio sources, so I wanted lots of inputs and a variety of gain settings. I also wanted it simple to use, so every adjustment is remote or manually controlled.

A unique feature I added is the Presence Control, which was born out of my frustration after finding some of my favorite recordings became unlistenable the more resolved my system became, regardless of the source.

This new feature deals with the harmonic balance of the mid and high frequencies. Now I can easily adjust the balance for every song.

I have been enjoying this in my own listening and am certain you will too.

Focus on the Music

With the Leto in your system it will allow the sonic detail to come through, so you focus is on the music and the hardware will seem to disappear.

What is Leto?

In Greek mythology, Leto is the mother of Apollo.

Presence

• 6 position remote or manual Presence control
• Presence  0,-1, -2, -3, -4, -5 (low pass shelf)
• 0 = Not engaged
• -1 = 13Khz and above
• -2 = 8Khz and above
• -3 = 4Khz and above
• -4 = 2Khz and above
• -5 = 1KHz and above
• When the unit is turned on, or you switch inputs, the presence control will go to “0”
• Presence control defaults to 0 which disengages from the circuit

 Gain

• 3 remote controlled Gain settings of 9dB, 6dB and 3dB 
• Manual Gain switch on rear panel 
• Gain setting is saved on each input

Detailed Specifications

• Remote control Input, Volume, Mute, Mono, Presence and Gain settings
• All adjustments can be operated manually (just in case the remote is misplaced)
• Frequency response 10Hz to 40Khz ~ 2dB
• Distortion ~ 0.013% with 1V RMS input
• Signal to noise ~ 100dB below operating level
• Non inverting output polarity
• Cross talk >90dB
• 1% metal film resistors throughout
• Polypropylene capacitors throughout the audio path

Power

• Newly designed internal power supplies using Toroidal transformers, 1 high voltage 300V and 1 low voltage 12VPower consumption 30W, 0 drain when off
• Voltage 100 to 120V AC 60Hz
• Optional factory installed 220V to 240V AC 50/60Hz
• Standard 3 pin IEC power connector
• ON/OFF power switch conveniently located on the side panel

Vacuum Tubes

• Two (2) Gold pin JJ ECC82/12AU7
• Two (2) JJ ECC832/12DW7
• High quality gold pin ceramic sockets

Other Features

• Each unit is hand made in the USA
• 50 hour factory burn in on all circuits and vacuum tubes
• Dimensions 17”w X 12”d X 5”h
• Weight 28 lbs.
• Shipping weight 30 lbs.(12.70 kg)
• Shipping box: 21”w x 21”d x 11”h (53.34cm x 53.34cm x 27.94cm)
• 16 gauge zinc plated steel enclosure
• Two year limited warranty
• Six months warranty on Vacuum Tubes
• Recessed RCA and XLR connectors are Gold plated with an isolated ground.
• All switches and knobs are easily accessible, nothing hidden inside to adjust.