EC21 vs Sonic Frontiers SFL-1 Signature
The SFL-1 Signature's signal-to-noise is 85 dB against the EC21's 90 dB, its thd 0.100% against 0.010%, its output voltage 2.0V RMS against 1.5V RMS, and its width 480 mm against 482.6 mm.
AI-generated product photo — not official manufacturer imagery.
DigitalActive CrossoversTube AmplifiersDiscontinued
Estimated price (community-sourced)
$650
Around — community and catalog average, updates slowly
About the EC21
The Audio Research Corporation EC21 is a vintage, active electronic vacuum-tube crossover—not a phono preamplifier, DAC, amplifier, or network-connected component. Available references identify it as a two-way crossover with an active tube low-pass section and a passive high-pass section. The low-pass filter is selectable for 6 dB/octave or 18 dB/octave operation, while the high-pass section is passive at 6 dB/octave.
Specifications
Power Specifications
Amplification power output and characteristics
- Input Sensitivity
- 1.5V RMS
Analog Output
Analog signal output specifications
- THD
- 0.010%
- SNR
- 90 dB
- Output Voltage
- 1.5V RMS
Connectivity
Input and output connections
- Bluetooth
- No
- Wi-Fi
- No
- Ethernet
- No
Physical Dimensions
Size, weight, and appearance
- Dimensions
- 482.6 × 133.35 × 260.35 mm (W × H × D)
Specifications are community-contributed and may not be accurate or complete. Verify all details with the manufacturer before making purchasing decisions. Terms & Conditions