POWERa Stereo
Karan Acoustics’ reference stereo power amplifier: 650 watts per channel into 8 ohms, fully balanced circuitry and enormous current reserves for commanding control of demanding loudspeakers. Hand-assembled in Europe.
Key Features
- Reference two-channel power amplifier
- 650 watts per channel into 8 ohms
- 1,100 watts per channel into 4 ohms
- 1,800 watts per channel into 2 ohms
- Peak output of 800 watts per channel into 8 ohms
- Fully symmetrical, truly differential and balanced circuit architecture
- Active Class A voltage-amplification stages
- No global feedback
- DC-coupled signal path without capacitors in the audio-signal route
- Balanced XLR and unbalanced RCA inputs
- Two 2,100 VA low-noise toroidal transformers
- 210,000 µF custom capacitor bank
- Ultra-wide bandwidth extending to 300 kHz
- Slew rate of 1,500 V/µs through the amplification stages
- Cardas Audio pure-copper internal wiring
- Critical Mass Systems isolation feet
- Massive aluminium chassis designed to reduce vibration, RF and electromagnetic interference
- Five-year parts-and-labour warranty
- Hand-assembled from individually selected and tested components
Design & Build
POWERa STEREO employs a fully complementary, symmetrical and differential signal architecture with no global feedback. Its amplification stages are DC-coupled, avoiding capacitors in the direct audio path, while proprietary servo circuits maintain safe and stable DC conditions.
Two independent 2,100 VA low-noise toroidal transformers and a 210,000 µF custom capacitor bank provide substantial current reserves for musical transients and difficult loudspeaker loads. Dedicated power-supply, filtration and regulation stages isolate the amplifier’s audio, protection and control circuits.
The massive aluminium chassis provides mechanical stability, heat dissipation and shielding from radio-frequency and electromagnetic interference. Cardas Audio pure-copper internal wiring and Critical Mass Systems isolation feet are fitted as standard.
System Pairing
With output rising from 650 watts per channel into 8 ohms to 1,800 watts per channel into 2 ohms, POWERa STEREO is designed to control large, low-sensitivity or impedance-demanding loudspeakers without requiring separate monoblocks.
Balanced XLR connection is recommended for a fully differential system and provides the natural pairing with Karan’s LINEa or LINEb preamplifiers. Unbalanced RCA sources can also be used with the supplied XLR shorting plugs installed as directed.
Technical Specifications
| Specification | Detail |
|---|---|
| Type | Fully balanced stereo power amplifier |
| Circuit topology | Fully symmetrical and differential; no global feedback; DC-coupled |
| Inputs | 2 × balanced XLR; 2 × unbalanced RCA |
| Input impedance | 30 kilohms, balanced or unbalanced |
| Input sensitivity | 2 V RMS for maximum output |
| Gain | +30 dB |
| XLR pin configuration | Pin 1: ground; Pin 2: positive; Pin 3: negative |
| RCA operation | Requires XLR shorting plugs |
| Power output into 8 ohms | 2 × 650 W |
| Power output into 4 ohms | 2 × 1,100 W |
| Power output into 2 ohms | 2 × 1,800 W |
| Peak power output | 2 × 800 W into 8 ohms |
| Frequency response | 20 Hz–20 kHz, ±0 dB; DC–300 kHz, –3 dB |
| THD | 0.03% |
| IMD | 0.03% |
| Rise and settling time | Less than 450 ns |
| Slew rate | 1,500 V/µs through the amplification stages |
| Signal-to-noise ratio | Greater than 120 dB, unweighted |
| Power transformers | 2 × 2,100 VA low-noise toroidal transformers |
| Capacitor bank | 210,000 µF, custom-made |
| Internal wiring | Cardas Audio pure-copper chassis wire |
| Isolation feet | Critical Mass Systems isolation/support feet |
| AC voltage | 115 V or 230 V nominal |
| AC voltage tolerance | ±10% from nominal voltage |
| Dimensions (W × H × D) | 504 × 292 × 603 mm |
| Weight | 105 kg |
| Warranty | Five years, parts and labour |
