TEMPEST II
Vacuum Tube Integrated Amplifier
Owner’s Manual
Rogue Audio, Inc.
3 Marian Lane
Brodheadsville, PA 18322
Issue date: 02/9/05
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 Tempest
II amplifier, you can be sure that you are getting the very best in tube
amplification. We at Rogue Audio are extremely proud of our products and want
you to enjoy them to their fullest potential. So please, take the time to read
through this short manual so that you can be confident that you have set up your
amplifier properly.
UNPACKING THE TEMPEST II INTEGRATED AMPLIFIER
Tools required: # 2 Philips Screwdriver
WARNING - This amplifier uses voltages that could cause injury or
death. Never open the amplifier while it is plugged in, and always wait
at least one hour after turning the unit off to unplug and open the unit.
Lethal voltages can remain in the electronics after the unit is
unplugged.
The Tempest II has been painstakingly inspected for cosmetic flaws during and
after assembly. In order not to damage the cosmetic appearance of your amplifier
it is important that you follow the unpacking instructions carefully.
1. Remove the Styrofoam packing material from the box, and remove the two
small white boxes. One of the boxes contains the Output Tubes, while the
other contains the power cord and remote control.
2. Lift the unit from the box, and carefully remove the protective plastic bag.
Remove the shipping pallet from the bottom of the amp. The pallet serves two
purposes. First, and foremost it acts to tie down the mechanically isolated
transformer platform. Secondly, it provides strength to the main chassis. Both
of these are critical to ensure that no damage occurs in transit.
3. Save the packing materials. The packing materials and box have been
carefully designed to protect your valuable equipment during shipping so you
don’t want to throw them away.
4. Remove the top cover of the amp using a #2 phillips screw driver to remove
the 10 cover screws. Using a glove or a clean dry cloth , install the tubes using
the diagram in Figure 1. The Output Tubes will have a label designating their
proper locations.
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Left Binding Post
Right Binding Post
Bias Meter
V1
V2
V3
V4
Potentiometers
Rotary Bias
Switch
6SN7
6SN7
External/Internal
Preamp Shunts
12AX7
12AX7
Figure 1 Tube and Deck Layout
INSTALLING THE TEMPEST II INTO YOUR SYSTEM
Amplifier Location:
The Tempest II depends on natural convection flow patterns for proper cooling.
To ensure proper cooling, the unit should be located in a position so that the
airflow is not impeded. The unit should not be placed in a fully enclosed shelf,
and should have a minimum of 8 inches of free space above it, and 6 inches of
free space on either side.
Connecting the Tempest II to the Loudspeakers:
The Tempest II 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
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your speaker or your local dealer to determine the correct choice. The amplifier is
factory set to 8 ohm.
To switch impedance setting:
1) Using a ½” wrench remove the outermost nut from the positive (red) binding
post.
2) Remove the 8 ohm tap (green wire marked 8) from the binding post. Be
careful to leave the black wire with heat shrink on the post.
3) Remove the polyurethane tubing from the unused 4 ohm wire (yellow) and
lug.
4) Place the 4 ohm wire onto the binding post and replace the outer nut.
5) Place the polyurethane tubing on the 8 ohm wire and lug.
CAUTION – Do not operate the amplifier unless it is connected to a
loudspeaker.
Connecting the Tempest II to the source components:
The input connections to the Tempest II 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.
Ultra Linear /
Triode Switch
Right Channel
Binding Post
Leftt Channel
Binding Post
Main Fuse
Figure 2. Rear panel layout
Connecting the Tempest II to the power outlet:
Connect the IEC end of the detachable power cord (provided) to the amplifier,
and plug the opposite end into the power outlet. It is recommended that the
Tempest II and all sources (CD, tuner, etc,) are plugged into the same wall outlet
if possible (perhaps using a power outlet strip) to avoid creating a ground loop.
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Connecting the Tempest II to a subwoofer:
The Tempest II has a pair of variable outputs on the back that are labeled
“variable out.” You can use these as preamp outs for driving a subwoofer. You
may also use the binding posts if your subwoofer is designed to connect directly
to these.
OPERATING YOUR TEMPEST II
1) Delays- Note that the Tempest is equipped with a slow turn-on feature that
protects other equipment from dangerous transients at turn-on as well as
significantly prolonging tube life.
2) Powering up the system - First turn on the amplifier by pushing in the “power”
button. The red LED will light showing that the unit is powered up. After
approximately 10 seconds the outputs will disconnect from ground. After
another 10 seconds, the control section will be unmuted and the Tempest is
ready to play music.
Note : This unit will not play for approximately 20 seconds after power
on while tubes warm up.
3) Switches and Controls - The Tempest II is equipped with volume, balance,
source, power, mute, and an optional remote volume .
• Volume – adjust gain from 0 to 23Volts out
• Balance - left and right channel attenuation
• Source - selects source material (CD, phono, tape, tuner, aux, preamp)
• Power - on/off operation
• Mute - mutes output
Remote Volume Control - The Tempest is optionally equipped with an analog
remote volume control feature. The volume may be adjusted manually using the
knob on the front panel, or by using the remote control provided.
4) Breaking in the amplifier - As with many high-quality audio amplifiers, the
sound of the Rogue Tempest amplifier will improve during the first 50 to 100
hours of use. This time is required for components to “burn in.” No special
techniques are required other than standard operation.
5) Passive preamplifier – The control section of the Tempest II consists of a
passive preamplifier section. You will probably need to turn the volume
control up higher than if you were using an active preamplifier circuit. This is
completely normal.
Note: This unit will not sound its best until the tubes have warmed up.
This will take approximately 5-10 minutes
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Note – Important! After turning off the amplifier, wait at least one minute to turn
it back on. Do not turn it on then off and then on again in quick succession.
Doing this will not allow the power supply to discharge between on/off cycling
and may result in transient noises.
USING AN EXTERNAL PREAMPLIFIER
The Tempest offers the flexibility of adding an external preamplifier should
the user wish to do so. In the external preamp mode the Tempest preamp is
completely bypassed and only the power amplifier section is used. To set up
the Tempest for use with an external preamp perform the following steps.
1) Remove the cover
WARNING - This amplifier uses voltages that could cause injury or
death. Never open the amplifier while it is plugged in, and always wait
at least one hour after turning the unit off to unplug and open the unit.
Lethal voltages can remain in the electronics after the unit is unplugged
2) Locate the four small shunts on the control circuit board as shown in figure 1.
3) Using a needle nose pliers carefully remove the four shunts from the locations
marked “int pre” and move them to the adjacent locations marked “ext pre.”
4) Rotate the selector knob to preamp on the front panel.
5) Connect the external preamp to the inputs on the rear panel marked preamp.
TRIODE ULTRALINEAR SWITCH
This switch is located on the back panel of the amp. See Figure 2. The output
transformer of a tube amplifier acts as the electrical interface between the very
different impedances of the loudspeaker and the tube circuitry. There are three
fundamental ways that the output transformer can be connected to the tube circuit.
1) Tetrode or Pentode connection – In this configuration, the highest power level
is achieved but at the expense of significantly higher distortion levels.
Practically speaking, this mode of operation is sonically inferior and has been
disregarded in the Tempest II design.
2) Triode connection – With this configuration, the lowest level of distortion is
achieved but at the expense of output power. In the case of the Tempest II, its
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power level in triode is high enough that it will likely provide plenty of power
for almost any speaker load.
3) Ultralinear operation – With this configuration, power levels near those of
tetrode mode are achieved with low distortion levels that approach those of
triode operation. For loudspeakers that demand very high levels of power,
ultralinear should provide excellent sound and plenty of power.
The triode/ultralinear switch allows the user to operate the Tempest II in either of
the two modes. In general, the sonic differences are subtle but for a given
loudspeaker one mode is likely to sound better than the other. There is a
complex relationship between the output transformer and the crossover network
so try both and see which one works best in your system. This switch can be
operated while the amplifier is playing but you will hear a small relay noise
through the loudspeaker.
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
Tempest II has been designed to be both simple and effective. On some amplifiers
biasing is done for two or more tubes simultaneously. With this method, the total
current flowing through the group of tubes may be correct, but the current flow
through any individual tube may vary significantly from the optimal value. With
the Tempest II the bias is set individually for each tube so that the correct
operating point is assured. An added benefit to this approach is that, should a
tube fail prematurely, the single tube can be replaced without having to purchase a
matched set. Use the following procedure to set the tube bias:
WARNING – There are dangerous and potentially lethal voltages inside this
amplifier. Do not touch any part of the amplifier other than as described
below. If you are uncertain about any of these instructions, please contact
your dealer and have them bias the amplifier for you.
1) Allow the amplifier to warm up for at least 30 minutes.
2) Turn the preamplifier volume completely off so that no signal is entering the
amplifier.
3) Remove the top cover. The bias tool is snap attached to the inside top of the
deck lid.
4) Locate the rotary switch and associated small potentiometers (they are blue
and have a small screw in the top). There are four, one for each tube. Note the
biasing meter.
5) Position the rotary switch into the corresponding tube position (ie. V1 for
output tube V1).
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Note – There is a small leakage current of 5mA that flows through the
meter’s shunt resistor during the tube bias setting operation. To accurately
account for this, set the bias current at 5 mA lower than the desired setting.
6) Using the bias tool, slowly turn the screw on the potentiometer that is adjacent
to the switch until the bias meter reads ~ 35 miliamps (actually 40mA.) Turn
the screw clockwise to lower the bias and counterclockwise to raise the bias.
Note that there are two ends on the bias tool. Using the end with the recessed
screwdriver will greatly facilitate this operation.
7) Repeat the above steps for each of the four output tubes.
8) Rotate the switch back into the null (first) position for operation.
As it is a quick operation, the tube bias should be checked every few months if
possible. Note that the bias will change slightly on a day to day basis as the wall
voltage fluctuates. Constant biasing will wear out the bias potentiometers
prematurely so do not adjust the bias unless it is more than 4-5 mA from the
correct setting.
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 Tempest II
and sources 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. If no meter reading can be attained, check the fuse (1/4
Amp slow blow). If the fuse is bad, replace the fuse and then set the bias. If the
bias will not maintain itself and the fuse blows again, the tube should be
replaced.
Output sounds distorted - Check the bias on the output tubes to ensure that the
tubes are operating properly.
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FUSE VALUES
Main fuse located on rear panel (1) – 5 Amp slow blow
Tube Fuses (4) – 1/4 Amp slow blow
SPECIFICATIONS
output power
frequency response
THD
90 WPC
5Hz – 50 kHz ± 1dB
< 0.1% typ, < 1% at rated power
1.0 V RMS
input sensitivity
dimensions
14 ½” W x 19” D x 7” H
60 pounds (25 Kg)
65 lbs (27 Kg)
weight
shipping weight
power requirements
115/230V - 50/60Hz
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OWNER AND WARRANTY REGISTRATION FORM
Included with this manual is an Owner and Warranty Registration Form. Please
take a minute to fill out this card and return it to Rogue Audio. This card must be
returned within 15 days of purchase to validate the warranty.
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. Rogue Audio warrants the vacuum tubes for a period of six months from the date of retail
purchase. Any defective parts will be replaced free of charge, excluding shipping and handling.
Proof of purchase in the form of a bill of sale or recited invoice which indicates that the product is within
the warranty period must be presented to obtain warranty service. Rogue Audio suggests that the purchaser
retain the dealer’s bill of sale as evidence of the date of retail purchase.
What’s Not Covered
This warranty does not cover cosmetic damage or any damage that results from product misuse, product
abuse, installation error, connection to an improper voltage supply, accident, improper maintenance,
alterations, modifications not authorized in writing by Rogue Audio, lightening, power surges, or acts of God.
Use of any other than Rogue Audio factory parts may void this warranty.
This warranty does not cover the cost of parts and labor which would be otherwise provided without charge
under this warranty, obtained from any source other than Rogue Audio.
This warranty applies only to consumer use of this product and does not cover any product that is used in
any trade or business, or in an industrial or commercial application.
This warranty applies only to the original purchaser of this product when purchased from an Authorized
Rogue Audio dealer. This warranty is not transferable.
This warranty is valid only in the United States.
YOUR RIGHTS
ROGUE AUDIO LIMITS ITS OBLIGATIONS UNDER ANY IMPLIED WARRANTIES UNDER STATE
LAWS TO A PERIOD NOT TO EXCEED THE WARRANTY PERIOD. SOME STATES DO NOT
ALLOW LIMITATIONS ON HOW LONG AN IMPLIED WARRANTY LASTS, AND SOME STATES
DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL
DAMAGES, SO THE ABOVE LIMITATIONS OR EXCLUSIONS MAY NOT APPLY TO YOU. THIS
WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY HAVE OTHER
RIGHTS WHICH MAY VARY FROM STATE TO STATE.
To Obtain Service
To obtain service, you must contact Rogue Audio and obtain a return authorization number. The product
must be delivered to Rogue Audio in its original packaging prepaid at the following address:
Rogue Audio Inc.
3 Marian Lane
Brodheadsville, PA 18322
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