PHONOa
Karan Acoustics’ reference two-chassis phono preamplifier: six phono inputs, selectable gain from 48 to 71 dB and five equalization curves for modern and historic recordings. Hand-assembled in Europe.
Key Features
- Reference two-chassis MM/MC phono preamplifier
- Three balanced XLR and three unbalanced RCA phono inputs
- Balanced XLR and unbalanced RCA line outputs
- Adjustable gain from 48 to 71 dB
- Multiple internal gain and cartridge-loading adjustments
- Five selectable equalization curves: RIAA, EMI, Decca, Columbia and Teldec
- Fully symmetrical, truly differential and balanced circuit architecture
- Active Class A operation with no global feedback
- DC-coupled signal path without capacitors in the audio-signal route
- Dedicated external power-supply chassis
- Separate power supplies and regulation for each audio channel
- Cardas Audio pure-copper internal wiring
- Critical Mass Systems CS2-1.0 isolation feet
- Massive aluminium chassis designed to reduce mechanical, RF and electromagnetic interference
- Five-year parts-and-labour warranty
- Hand-assembled from individually selected and tested components
Design & Build
PHONOa separates its sensitive low-level amplification and equalization circuitry from the power supply in two matching enclosures. Its fully symmetrical and differential architecture operates in active Class A without global feedback, preserving the minute timing, harmonic and spatial information retrieved from a phono cartridge.
The DC-coupled signal path avoids capacitors in the direct audio route, while proprietary servo circuits control DC offset. Separate transformers, filtration and regulation are provided for each audio channel and the control circuitry.
Its substantial aluminium chassis helps protect the low-level phono signal from radio-frequency, electromagnetic and mechanical interference. Cardas Audio pure-copper internal wiring and Critical Mass Systems CS2-1.0 isolation feet are fitted as standard.
System Pairing
With three balanced XLR and three unbalanced RCA inputs, PHONOa can accommodate multiple turntables, tonearms or cartridges in a reference analogue system. Its adjustable gain range supports both moving-magnet and moving-coil cartridges.
Five equalization curves allow correct playback of records mastered to RIAA and several important historic standards. Balanced XLR and unbalanced RCA outputs provide flexible connection to a line preamplifier or integrated amplifier.
Technical Specifications
| Specification | Detail |
|---|---|
| Type | Two-chassis fully balanced MM/MC phono preamplifier |
| Circuit topology | Active Class A; fully symmetrical and differential; no global feedback; DC-coupled |
| Phono inputs | 6 total: 3 × balanced XLR; 3 × unbalanced RCA |
| Line outputs | 1 × balanced XLR; 1 × unbalanced RCA |
| Supported cartridges | Moving magnet and moving coil |
| Gain | Adjustable from 48 to 71 dB |
| Phono equalization | RIAA, EMI, Decca, Columbia and Teldec |
| RIAA accuracy | ±0.1 dB |
| EMI accuracy | ±0.15 dB |
| Decca accuracy | ±0.15 dB |
| Columbia accuracy | ±0.15 dB |
| Teldec accuracy | ±0.1 dB |
| Output impedance | 90 ohms |
| Nominal output level | 1.55 V RMS |
| Maximum output level | 18 V RMS, balanced into a 600-ohm load |
| Frequency response | 20 Hz–20 kHz, ±0 dB; 1.5 Hz–1 MHz, –3 dB |
| THD | 0.003% at full output, 20 Hz–20 kHz |
| IMD | 0.003% at full output |
| Rise and settling time | Less than 450 ns |
| Slew rate | 1,500 V/µs through the amplification stages |
| Signal-to-noise ratio | Greater than 90 dB for MM; greater than 81 dB for MC |
| Internal wiring | Cardas Audio pure-copper chassis wire |
| Isolation feet | Critical Mass Systems CS2-1.0 |
| Power supply | Dedicated external power-supply chassis |
| AC voltage | 115 V or 230 V nominal |
| AC voltage tolerance | ±10% from nominal voltage |
| Maximum power consumption | 60 W |
| Dimensions (W × H × D) | Main unit: 504 × 141 × 390 mm; power supply: 504 × 141 × 390 mm |
| Weight | Main unit: 15 kg; power supply: 17.1 kg |
| Warranty | Five years, parts and labour |
