The Rogue Audio Stereo 90 Super Magnum is the kind of push-pull tube amplifier that makes American hi-fi feel like it has something to prove — and then proves it. Built by hand in Brodheadsville, PA and factory-upgraded with Cardas hardware, HexFred rectifiers, PRP resistors, and polypropylene bypass caps throughout, it arrives with real physical authority: bass that grabs and holds, a midrange that puts the performers right in the room with you, and a treble that stays composed and unhurried no matter the program. Flip it to triode and the whole character softens and blooms — a genuinely different amp, narrower and warmer, more candlelit. The TAS Editors chose it for a reason. This is what 90 serious watts sounds like when someone actually cared about every resistor.
Production
2004-2013
Condition
Cosmetic 9/10 - Electronic 10/10
Serial No.
r88-0514
Orig. MSRP
$2,995
Restoration
- Verified/adjusted bias
- Unit is performing at factory spec
- Cleaned and lubricated all controls
- Thoroughly detailed
Factory Specs
Output Power 90W per channel
Frequency Response 5Hz–50kHz ± 1dB
Total Harmonic Distortion (THD) <0.1% typical; <1.0% at rated power
Input Sensitivity 1.0V RMS
Minimum Input Impedance 200K Ohms
Circuit Topology Class A/B, push-pull, transformer-coupled
Output Mode Triode or Ultralinear, user-selectable via rear-panel toggle switch
Output Impedance Taps 4Ω and 8Ω, user-selectable (internal jumper)
Output Tubes (Super Magnum) (4) KT90 (matched quad; KT120 also compatible)
Signal Tubes (2) 6SN7 — one per channel
Phase Inverter Tubes (2) 12AX7 — one per channel
Bias Supply Rectifiers HexFred (HEXFRED) ultrafast diodes replacing standard diodes
Screen Grid Resistors Upgraded (higher-precision types)
Filter Bypass Capacitors Polypropylene bypass capacitors added across filter electrolytics
Coupling Capacitor Bypass Bypass capacitors added across coupling caps
Signal Path Resistors PRP (Precision Resistor Products) resistors in all critical audio-path positions
Binding Posts Cardas binding posts (replacing stock gold-plated posts)
RCA Input Jacks Cardas RCA jacks
Internal Wiring Upgraded internal hookup wiring throughout
Small Signal Tubes Upgraded 6SN7 and 12AX7 small-signal tubes
Output Transformers Ultra-wide bandwidth, custom-wound; mechanically isolated from chassis
Power Supply Massive fully regulated high-voltage supply
Circuit Board 2-ounce copper PCB
Faceplate Machined aluminum faceplate
Tube Bias System Built-in bias meter with per-tube adjustment (4 individual trim pots)
Tube Protection Integral tube cage (removable); individual 200mA slow-blow fuse per output tube
Power Requirements 115/230V – 50/60Hz (switchable)
Main Fuse 5A slow-blow (rear panel)
Output Tube Fuses (4) 200mA (2/10A) slow-blow, one per output tube
Dimensions 18 × 7 × 15.75 in (W × H × D)
Weight 60 lbs
Documentation
Rogue Audio Stereo 90 Owner's Manual
Liner Notes
Whether your tastes run to the delicate strains of the violin or the wail of the electric guitar, the Rogue Stereo 90 power amplifier will thrill you with its precision, musicality, and impact. And with 90 watts of pure tube power, you can be sure that your amplifier won't run out of steam before the musicians do. The heart of the Stereo 90 consists of four matched KT88/6550 output tubes operating in push-pull configuration. A massive fully regulated power supply ensures that low frequency information will not go unheard, and that the power and attack of transient musical passages will be recreated in full. And with a simple flip of a switch, audiophiles can choose between pure triode and ultra-linear operation to suit their tastes and power requirements. The transparency and power of the Stereo 90 is testimony to a design that truly transcends that of the competition.
While the build quality is readily evidenced in the exquisitely sculpted appearance of the Stereo 90, the beauty of this amplifier is more than just skin deep. From the heavy-duty gold plated RCA inputs to the custom wound output transformers, the audio signal travels through only the finest components available. With this winning combination of leading edge circuit topology, great components, and a stunning appearance, you can be certain that you are investing in amplifier design that only Rogue Audio can deliver.
Shipping
To ensure safe arrival, we often use private couriers. These are transporters in Sprinter Vans or pulling covered trailers often moving art and antiques across the country. Absolutely the safest way to ship short of you picking it up yourself. This piece ships to the contiguous United States for a flat rate of $300, which includes our packaging and our insurance. Of course, we'll ship anywhere in the world, just drop us a line and we'll give you an estimate – even if you're just curious.
Stock No.
15430646268125
