Owner manual

Valve Amplification Company

1731 Northgate Boulevard, Sarasota, FL 34234 USA

Telephone 941-359-2066 / Fax 941–359-2057

www.vac-amps.com

VAC VINTAGE PREAMPLIFIER Mk III

Operating Instructions

DO NOT OPEN THIS UNIT - THERE ARE NO USER SERVICEABLE PARTS INSIDE.

DO NOT TOUCH TUBES UNTIL UNIT HAS BEEN SWITCHED OFF FOR 5

MINUTES. TUBES BECOME HOT IN USE. DO NOT EXPOSE THIS UNIT TO

MOISTURE. DO NOT PLUG INTO AN AC SOURCE UNTIL ALL CONNECTIONS

ARE COMPLETED.

Introduction

The Vintage Preamplifier features a zero-global-feedback, Class A, triode line amplifier &

controller, and a Class A triode phono amplifier employing both passive and active RIAA

equalization techniques. It is to be operated from the voltage labeled on the back panel, 50-

60 Hz. The fuse is a slow blow type of the size labeled on the back of the unit.

Connection

1.Complete all connections before connecting the AC cord to the wall outlet.

2.At turn on, the volume control should be full counter-clockwise and the mode switch

should be set to MUTE. Also, always MUTE the preamp before switching power off,

to prevent damage to amplifiers or speakers.

3.Allow 30 seconds for warm up before leaving MUTE.

4.The Vintage Preamplifier inverts phase from all inputs to the main outputs. To correct

for this reverse the speaker connections in both channels. Output to the tape jacks

does not invert.

5.In normal operation no signal is present at the tape output jacks. This is done to

ensure that no degradation of sound occurs due to input non-linearities or loading

PAGE 1
Valve Amplification Company 1731 Northgate Boulevard, Sarasota, FL 34234 USA Telephone 941-359-2066 / Fax 941–359-2057 www.vac-amps.com VAC VINTAGE PREAMPLIFIER Mk III Operating Instructions DO NOT OPEN THIS UNIT - THERE ARE NO USER SERVICEABLE PARTS INSIDE. DO NOT TOUCH TUBES UNTIL UNIT HAS BEEN SWITCHED OFF FOR 5 MINUTES. TUBES BECOME HOT IN USE. DO NOT EXPOSE THIS UNIT TO MOISTURE. DO NOT PLUG INTO AN AC SOURCE UNTIL ALL CONNECTIONS ARE COMPLETED.
PAGE 2
effects of the tape recorder. To record, select the record enable position ("TAPE ON") of the TAPE MONITOR switch. If you wish to monitor the output from the recorder's monitor head (if so equipped) select the monitor position ("MON"). It is recommended that this switch not be cycled during important recordings. 6.
PAGE 3
mechanical or acoustic stimulation encountered when the unit is properly installed and playing music. Replace the offending tube if excessive mechanical sensitivity or ringing occurs. It is best not to subject the tubes to tapping or the chassis to repeated mechanical jars, as this may damage the precision of the tubes and cause them to become more microphonic. About Noise Every amplifying device produces some amount of noise. In fact, even a resistor produces noise in the presence of current flow.