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CAD 808/Rocket 88 R
Stereo Vacuum Tube
Power Amplifier
INITIAL SET UP
and
OWNERS MANUAL
NOTE: Before installing your new power amplifier, please read this manual carefully as it will inform
you of the specifications, proper installation procedures and operation procedures. Also included in this
manual are guidelines on how to properly service and care for your new Rocket 88 R.
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Dear Audiophile Friend: I would like to take this opportunity to personally thank you for purchasing a Cary Audio Design Rocket 88 R stereo power amplifier. I have spent many, many hours designing and voicing this latest iteration of our very popular Rocket 88. In fact, I have had tremendous fun listening to the new Rocket 88 R during and after the design phase. There are several design projects that stand out to me in the recent past. The three design projects that immediately come to my th min
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THEORY OF OPERATION For the technically minded, a review of the circuit is in order. Your new Rocket 88 R operates in push pull triode Class A mode and in class A/B ultra-linear mode. The output stage KT-88 tubes are biased with a negative fixed bias voltage for low distortion and maximum output capabilities. In the triode mode, the Rocket 88 R is the most linear and yields the most musically satisfying presentation. The output power is 30 watts of triode power per channel and 60 watts per chann
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even higher overall power output levels to try to solve the clipping problem. In reality, we believe the most critical aspect is how fast a recovery an amplifier can achieve after overload. With the incredible dynamics range of live and recorded music, even 2,000 watts of power is potentially not enough. Most of the music being listened to in an average home listening room is only requiring about 1-3 watts of power. It is on the transients of loud low frequency program material that tremendous s
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DIMENSIONS: 10”W x 18”D x 6”H (25.4 cm x 45.7 cm x 15.2 cm) WEIGHT: 45 Lb.. (20.4 kg) CIRCUIT TYPE: Push-Pull Triode Class A, Ultra-linear Class A/B POWER OUTPUT: 30 Watts Triode, 60 Watts Ultra-linear INPUT SENSITIVITY: 1.2 volt for full output INPUT IMPEDANCE: 150,000 ohms NOISE AND HUM: -87 dB below rated output FREQUENCY RESPONSE: 10 Hz to 82,000 Hz + 0, -3.0 dB @ 1 watt TUBES: 2-12BZ7 Dual Triode, Phase inverter, gain stage (12AX7, 12AY7) 2-EL-84 Current source (or 6BQ5) 4-KT-88 Output tub
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Front Panel Features AC-ON ROTARY SWITCH: Turns AC power on in the “on” position. GREEN ‘CAT EYES’: Indicate audio power output, fully closed eye at maximum power. Rear Apron Features INPUT: Signal input connection via either RCA or XLR shielded interconnect cables. Pin #1 is the shield, #2 positive phase signal on XLR connector. INPUT SWITCH: Push in direction of the type of input to be utilized, RCA or XLR. OUTPUT: The 5-way speaker binding posts provide the output to the speaker system. Red p
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connected. You may plug in the test plug while the unit is playing. You may hear a slight click in the loudspeakers when inserting or removing the plug. This is normal. SPEAKER: These switches change the 4 and 8 ohm output taps from the output transformer to the speaker posts on the rear of the amplifier. They maybe operated with the amplifier in operation. EYE TUBE: There are two of these. They set the green eye tube intensity. You may set to any desired level for your listening room. The contr
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Amplifier Placement and Set Up In general, the location of your new Rocket 88 R amplifier is not critical. The best placement in your system is near the speaker system with short lengths of speaker cables. Certain precautions must be taken to ensure optimum performance. Avoid hot locations near radiators or other heating units. Keep the top of the Rocket 88 R clear of books, paper, or other equipment to protect against overheating. Power Requirements The Rocket 88 R is designed to operate from h
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illuminated. Should you not observe the above conditions, turn off the amplifier and check the power cord and AC socket. Triode/Ultra-Linear Switch On the top of the chassis behind the KT-88 output tubes is located a chrome handle switch. With the handle pushed to the rear of the amplifier the mode of operation is ultra-linear. In the forward position the mode will be in triode class A mode. This set of switches maybe switched during listening. A slight click maybe heard in the loudspeakers. Thi
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Break In Period The tubes, capacitors and output transformers take approximately 100 hours of music playing to fully settle in for peak performance. The Rocket 88 R will sound good fresh out of the box. However, after the first couple of hours you will notice increased depth and tighter bass. This break in period is normal for tube based components and with high performance audio components. SERVICE AND CARE WARNING! MAKE SURE AMPLIFIER IS UNPLUGGED FROM AC MAINS Care and Cleaning The chassis of
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WARNINGS! MAKE NO ATTEMPT TO PUT THE ROCKET 88 R INTO SERVICE OUTSIDE OF THE CABINET. CONTACT WITH THE HIGH VOLTAGES FOUND INSIDE THE UNIT CHASSIS CAN BE FATAL! COMPLETELY REMOVE THE AC POWER PLUG FROM THE WALL AND ALLOW 30 MINUTES FOR THE HIGH VOLTAGE CAPACITORS TO DISCHARGE THROUGH THE BLEEDER RESISTORS BEFORE YOU ATTEMPT TO CHANGE THE TUBES OR TO CLEAN THE INSIDE OF THE AMPLIFIER! CAUTIONS NEVER REMOVE or INSERT AC PLUG WHEN THE UNIT IS ON OR THE AC POWER SWITCH IS IN THE “ON” POSITION. OBSTR
