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)Turn on all sources (CD, tuner, etc.) that you will be using.

2)Turn on the preamplifier.

3)Wait until preamp has stabilized.

4)Power up Stereo 90 amplifier

5)Select listening source and play music

When powering down your system turn the amplifier off first.

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.

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 Stereo 90 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 Stereo 90, its 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 Stereo 90 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.

Stereo 90 specifications

Rogue Audio Stereo 90 is a high-performance power amplifier that stands out in the competitive landscape of audiophile equipment. Renowned for its exceptional sound quality, the Stereo 90 embodies a blend of innovative technology and classic design principles, making it a favorite among music enthusiasts and professionals alike.

At the core of the Rogue Audio Stereo 90 is its all-tube design, which delivers a warm, rich sound that many audiophiles cherish. It utilizes a pair of KT90 output tubes, known for their high power handling and superb linearity. This tube configuration enables the amplifier to produce up to 90 watts per channel into an 8-ohm load, making it versatile enough to drive a wide range of speakers with ease and finesse.

One of the standout features of the Stereo 90 is its push-pull topology, which enhances the performance of the amplifier by minimizing distortion and improving overall efficiency. This design approach allows the Stereo 90 to maintain clarity and detail across the frequency spectrum, delivering a lifelike and engaging listening experience.

In addition to its exceptional sound quality, the Rogue Audio Stereo 90 also boasts a robust, high-quality build. Its chassis is constructed from heavy-duty steel, ensuring durability while also minimizing vibrations that can negatively impact audio performance. The amplifier is equipped with high-quality components throughout, including premium capacitors and transformers, which further contribute to its reliability and sonic excellence.

For ease of use, the Stereo 90 features a front-panel bias adjustment, allowing users to easily set the bias on the output tubes for optimal performance. The amplifier also includes a variety of input options, including RCA inputs, making it compatible with a broad range of source components.

The aesthetic appeal of the Rogue Audio Stereo 90 cannot be overlooked. Its classic design features an attractive black chassis with chrome accents, giving it an elegant yet timeless look that will complement any audio setup. The rotary controls add a touch of vintage charm while also providing intuitive access to its features.

In summary, the Rogue Audio Stereo 90 is a powerhouse amplifier that combines advanced tube technology with meticulous craftsmanship. With its ability to deliver stunning audio fidelity, it has become a cornerstone in many audiophile systems, captivating listeners with its detailed soundstage and dynamic range. Whether used for casual listening or critical listening sessions, the Stereo 90 proves to be an exceptional choice for anyone looking to elevate their audio experience.