VAC Renaissance Mk I Preamplifier User Manual

VAC Renaissance Preamplifier

Operation & Maintenance Information

Valve Amplification Company

Manual issued 02/21/2001

CAUTION

THE POWER SUPPLY UNITS CONTAIN NO USER SERVICEABLE PARTS. DO NOT REMOVE THE
COVERS. LETHAL VOLTAGES ARE PRESENT WITHIN THE CHASSIS.

NEVER OPERATE THE PREAMPLIFIER WITH THE AUDIO CHASSIS COVERS REMOVED. BEFORE
OPENING TO CHANGE TUBES, DISCONNECT THE PREAMPLIFIER FROM POWER AND ALL
OTHER COMPONENTS, AND ALLOW IT TO SIT TURNED OFF FOR 30 MINUTES.

DO NOT OPERATE THE UNITS IF THEY ARE WET.

THE PREAMPLIFIER AND POWER SUPPLY UNITS ARE HEAVY. BE SURE TO USE PROPER LIFTING
TECHNIQUES TO AVOID BACK STRAIN AND INJURY. BE CERTAIN TO INSTALL IT IN A SECURE
LOCATION FROM WHICH IT CAN NOT FALL OR TIP OVER.

INDEX

Introduction

Installation

Inputs (back panel)

Outputs & Grounding Switch (back panel)

Operation

Front Panel Controls

Remote Control

A Word About Tubes in General

Replacement of Tubes

Warranty & Registration Form

INTRODUCTION

The Renaissance Preamplifier is among the world’s finest audio preamplifiers, second only
to the VAC Renaissance Signature Preamplifier. Sharing similar circuit designs, they are
absolutely unique components. Unusual topology, premium parts, and flexibility make them
a pleasure to hear and operate.

The line stage is, in effect, a small Class A1 power amplifier, capable of driving loads as low
as a few hundred ohms. This is a stark contrast to normal preamplifiers, which claim a low
output impedance but completely collapse when asked to deliver current. The Renaissance
circuit is loafing with a normal load in the 10,000 to 200,000 ohm range, delivering an
effortless, musical performance.

There is no feedback and no coupling capacitors in the line section. All active elements are
triode tubes, the purest, most linear amplifying devices yet invented. Output matching is
accomplished by way of superb output transformers. As a side benefit, different output
grounding configurations are possible, optimizing performance into either balanced or
single-ended loads, and allowing ground loops to be broken.

The optional triode tube phono stage has moderately high gain with a very low noise floor.
Low output MC cartridges are accommodated by means of high quality matching
transformers, which contribute voltage gain without noise, resulting in detail that emerges
from a remarkably dark and neutral background.

Remote control is implemented via motorized mechanical devices. This is expensive, but
provides two major advantages. First, the Renaissance Preamplifier controls are completely
intuitive to use. Second, we avoid the sound degradation attendant with VCAs, relays,
transistor switches, and switched resistor arrays.

The massive chassis is machined from quarter inch thick aluminum plate and fitted with
damping material for a strong, resonance-resistant structure. The sculpted aluminum fascia
has a hand rubbed gloss lacquer finish.

The audio circuitry and power supply are completely hand wired.

You will notice the sound quality of the Renaissance Preamplifier improve during the first few
hundred hours of operation, particularly with regard to subjective frequency extension.

The Renaissance Preamplifier is designed not to the latest fad but to substance, for the
highest possible sound quality. Time spent familiarizing yourself with this manual will be well
rewarded.