VAC Signature Preamplifier Mk I User Manual

VAC Renaissance Signature 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 VERY 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)

Logo Illumination (back panel)

Operation

Front Panel Controls

Remote Control

Replacement of Tubes

A Word About Tubes in General

Warranty & Registration Form

INTRODUCTION

The Renaissance Signature Preamplifier is the world’s finest audio preamplifier and an
absolutely unique component. Its unusual topology, premium parts, and flexibility make it
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
Signature circuit is loafing with a normal load in the 10,000 to 200,000 ohm range, delivering
an effortless, musical performance.

There is no loop 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 phono stage uses six twin triodes operating without loop feedback. Gain is
moderately high, 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. A
completely separate power transformer and filter system is provided for the phono stage,
eliminating all unwanted interaction with the line stage.

Remote control is implemented via motorized mechanical devices. This is expensive, but
provides two major advantages. First, the Signature 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 half-inch thick fascia has a
hand rubbed gloss lacquer finish.

The audio circuitry and power supply are completely hand wired.

The Renaissance Signature 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.

INSTALLATION

1)Provide adequate ventilation.

2)Do not operate on carpet or any other surface that might block air flow.

3)The chassis will become warm in normal use.

4)Do not allow the chassis to touch any metal parts, such as the frame of an equipment
rack. This might create a parallel ground path that could degrade the sound of your
system.

5)Input connection is via single ended RCA jacks or XLR jacks (which can be from
balanced or unbalanced sources). Output can be on RCA or XLR jacks, and can be
set for balanced or unbalanced loads, with or without ground connection at the
preamplifier. IMPORTANT: READ THE SECTION ON “OUTPUTS & GROUNDING
SWITCH”. Connect line level inputs (CD, Tuner, Tape, etc.) to the appropriate RCA
input jacks on the rear panel. Note: with the exception of Phono (when fitted), all
inputs are “line level”

6)Connect phono cables to the rear panel MM or MC inputs labeled “Phono.” Connect
the ground wire from the turntable or phono cable to the “Ground” terminal
provided on the rear panel. Set the MM / MC switch to reflect the input jacks being
used.

7)Connect the power cables from the power supply to the preamplifier. Note that
each has a locating key and a locking collar. Be sure to insert the connector properly,
and fully tighten the locking collar.

8)Connect the input and output cables.

9)Connect the power supply to the power source indicated on the rear panel, either
100, 120, 220, or 240 volts AC. The voltage may be select by means of the
removable selector card located underneath the fuse in the power connector.
Remove the cards and reinstall so that the desired voltage may be read. Avoid
power conditioners that float the ground pin. ALWAYS connect power cord to
component before plugging it into an AC outlet, and make sure that unit’s power
switch is set to the “off” position before making the final connection. For best
performance, try to route the power cord away from signal cables.

10)Pay close attention to power quality, and be aware that different power cords can
alter the sound. The backlit meters show variation in power line voltage as reflected
to the audio circuitry.

11)Set the logo illumination switch to bright, dim, or off.