Related Manuals for VAC Phi 300,1
Summary of Contents for VAC Phi 300,1
- Page 1 300.1 The VAC Phi Three Hundred Stereo/Mono Beam Power Amplifier Operation & Maintenance Information Valve Amplification Company Manual issued 03/06/2007...
- Page 2 CAUTION - SAFETY NOTICE THE AMPLIFIER CONTAINS NO USER SERVICEABLE PARTS. DO NOT REMOVE THE BOTTOM PLATES OR CHASSIS COVERS. LETHAL VOLTAGES ARE PRESENT WITHIN THE CHASSIS. DO NOT OPERATE THE UNITS IF THEY ARE WET. VACUUM TUBES BECOME HOT ENOUGH TO CAUSE SERIOUS BURNS. NEVER TOUCH A TUBE WHEN THE UNIT IS ON.
- Page 3 INDEX Introduction Installation Installing the front glass and top bars Input connectors Operation Feedback Triode & Ultra-Linear Modes Illuminated Logo Installing New Output Tubes Biasing & Checking Output Tube Condition Replacement of Low Level Tubes Care Of Chassis Tips and Advice A Word About Tubes in General Output Tubes Low Level Tubes...
- Page 4 INTRODUCTION The Phi 300 is a unique power amplifier, and the most powerful and detailed in VAC’s history. Featuring a new direct-coupled input & driver circuit, extremely fast and vivid sound is achieved from both single-ended and balanced sources. The Phi 300 may be used as a 150 watt/channel stereo amplifier, or as a 300 watt monophonic amplifier, as determined by the rear panel switch.
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Page 5: Installation
Install the vacuum tubes. Each tube or its box has a “V” number, which corresponds to the labels on the top Tube Placement - VAC Phi 300 plate of the amplifier; these indicate where each tube should be installed. Fit each tube into the matching socket. - Page 6 Connect the power cord to the power source indicated on the rear panel (will be either 100, 120, 220, or 240 volts AC). Voltage conversions must be done at the factory of by an authorized VAC importer. Avoid power conditioners that float the ground pin.
- Page 7 INSTALLING THE FRONT GLASS AND TOP RAILS Your amplifier has been shipped with the front acrylic glass and the top rails romoved. The following steps show how these are installed. The glass installs in the groove at the top of the fascia. Insert it at a slight angle, as shown.
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Page 8: Operation
3,000 to 8,000 hours. For best tube life, turn the amplifier off when you are not listening. Any time that the VAC Power Amplifier has not been used for a few weeks the sound may be different. This is also normal for high resolution audio equipment. Optimum sound should return after a few hours of operation, preferably with an audio signal. -
Page 9: Triode & Ultra-Linear Modes
1937. Both modes of operation are available with your VAC Phi amplifier via a single switch on the top plate. Although the mode may be changed with the amplifier in operation, we strongly suggest that you... - Page 10 First, see the SAFETY NOTICE earlier in the manual. Output tubes are type KT88. Replacement output tubes should be purchased from VAC. It is desirable that tubes be in matched quartets for each channel, and be close to the "bogey" values for the major parameters.
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Page 11: Output Tube Bias Adjustment
CHECKING OUTPUT TUBE CONDITION The condition of each individual KT88 output tube should be checked with the built in meter. By operating the test switches beside the light, the meter will display the exact idle current in the tube - this is used in setting the bias. Be certain to stop the music before making the reading. Typically, the meter will indicate near the dot at the center of the scale. -
Page 12: Care Of Chassis
A Word About Low Level Tubes. CARE OF CHASSIS VAC chassis are machined aluminum for superior electromagnetic performance. The main chassis is finished in a durable clear powdercoat paint. Cleaning the unit with a damp cloth WHILE THE AMP IS SWITCHED OFF AND UNPLUGGED should suffice. Do not get cleaning solutions onto or into the... - Page 13 It is normal to see a slight violet glow in a power tube such as a 300B or EL34. However, a vivid violet indicates excess current flow through the tube and should be investigated. VAC can test tubes for concerned customers.
- Page 14 Your VAC Amplifier uses the KT88 kinkless tetrode. It is strongly recommended that replacement tubes be purchased only from VAC. If, however, you want to customize the sound to your tastes, be aware that as with interconnects and speaker cables, each tube manufacturer's KT88 tends to have a distinct sound, as well as its own reliability profile.
- Page 15 Contrary to popular misconception, no power is lost due to unused output taps. For more information consult VAC Technical Monograph 90-9, which may be viewed on our wesite (http://www.vac-amps.com).
- Page 16 Keep the audio cables as close together as possible. Keep the AC cords away from the audio cables. Try different ground settings on your preamplifier, if it has them. For example, the VAC Signature, Phi, and Renaissance preamplifiers may be set to “ungrounded” or “XLR” audio modes.
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Page 17: Specifications
SPECIFICATIONS The VAC Phi has been developed with the critical ear as the major arbiter of quality, with both conventional and unique measurements providing insight and guidance as necessary. The lack of emphasis on measurements is due to the fact that engineering's arsenal of equipment and techniques do not operate on the pattern recognition principals that control human perception of sound. -
Page 18: Warranty
Your equipment is warranted for a period of thirty (30) days from the date of purchase. In addition, if the registration form is received by VAC along with a copy of your sales receipt from an authorized VAC dealer within this thirty days, a service contract will be extended to cover your equipment for two (2) years (tubes excepted).