Stereo 90 Vacuum Tube Power Amplifier Owner’s Manual Rogue Audio, Inc.
TABLE OF CONTENTS 1) Introduction 2 2) Unpacking the Stereo 90 power amplifier 2 3) Installing the Stereo 90 into your system 3 4) Operation of the amplifier 5 5) Setting the tube bias 6 6) Troubleshooting 7 7) Owner and Warranty Registration Form 7 8) Fuse values 8 9) Specifications 8 10) Warranty 9 1
INTRODUCTION Congratulations on your purchase decision! We at Rogue Audio truly believe that our amplifiers provide the “smartest” value in high-end audio. If you have never owned a vacuum tube amplifier you will be thrilled by the silky-smooth sound and incredible detail that only a tube amplifier can provide. And with the Stereo 90 amplifier, you can be sure that you are getting the very best in tube amplification.
Left Binding Post Right Binding Post Bias Meter V1 V1 V2 V3 V4 Potentiometers Rotary Bias Switch 12AX7 Bias Tool 6SN7 Figure 1 Tube and Deck Layout INSTALLING THE STEREO 90 INTO YOUR SYSTEM Connecting the Stereo 90 to the Loudspeakers: The Stereo 90 provides options for either 4 or 8 ohm speakers. The impedance selected will depend on the speakers used. Consult either the owner’s manual for your speaker or your local dealer to determine the correct choice. The amplifier is factory set to 8 ohm.
CAUTION – Do not operate the amplifier unless it is connected to a loudspeaker. Connecting the Stereo 90 to the preamplifier: The input connections from the preamplifier are made via RCA jacks on the rear of the amplifier. See figure 2. Be sure to use high quality interconnect cables – they do make a difference. Left Channel Binding Post Right Channel Binding Post RCA Inputs Ultra Linear/ Triode Switch Figure 2.
OPERATION OF THE AMPLIFIER After all proper connections have been made, you are now ready to turn the Stereo 90 amplifier on. The power on/off switch is on the front of the amp. Some preamplifiers and sources can generate dangerous transients that can damage loudspeakers. To avoid letting dangerous transients reach your loudspeakers turn your system on in the following order: 1) 2) 3) 4) 5) Turn on all sources (CD, tuner, etc.) that you will be using. Turn on the preamplifier.
SETTING THE TUBE BIAS Tools required: bias tool (provided with amplifier) The output tubes (the big ones) need to be “biased’ with a grid voltage that controls the flow of electrical current through the tube. Tube biasing on the Stereo 90 amplifier has been designed to be both simple and effective. On some amplifiers biasing is done for two or more tubes simultaneously.
) Rotate the switch back into the null (first) position for operation. As it is a quick operation, the tube bias should be checked on a regular basis. TROUBLESHOOTING Speaker Hum – If hum can be heard from more than a few inches from the loudspeaker, there is probably a ground loop. Be sure to have both the amp and preamp plugged into the same outlet if possible. Tube will not bias – If the meter provides a reading but the tube will not bias, the tube is probably bad.
FUSE VALUES Main fuse located on rear panel (1) – 5 Amp slow blow Tube Fuses (4) – 2/10 Amp slow blow SPECIFICATIONS output power 90 WPC frequency response 5Hz – 50 kHz ± 1dB THD < 0.1% typ, < 1% at rated power input sensitivity 1.
LIMITED WARRANTY Warranty Period This product has been manufactured under the highest standards of quality and workmanship. Rogue Audio Inc. (hereinafter “Rogue Audio”) warrants this product against defects in material or workmanship as follows: With the exception of vacuum tubes, Rogue Audio warrants to the original purchaser of this product all parts of this product against defects in material and workmanship for a period of three years from the date of retail purchase.
