S20EXD Parallel SE w/EXD

About the S20EXD Parallel SE w/EXD

The BorderPatrol S20EXD Parallel Single-Ended Amplifier features a dual mono design with point-to-point wiring and uses interstage transformers to couple NOS Sylvania 6DR7 double triode input tubes to Western Electric 300B output tubes running in parallel single-ended mode (2 per channel), delivering 18 Class A watts per channel. It includes twin massive external power supplies (35 lbs each) that provide independent tube-rectified, choke input filter supplies for high voltage, driver tube, and bias voltages. The chassis combines wood and copper elements and is cryogenically treated along with the power supplies. The amplifier is recommended for loudspeakers with efficiency above 90dB and impedance not dropping below 4 Ohms. It offers 4 and 8 Ohm speaker outputs, single-ended RCA inputs, and optional volume control. The design emphasizes naturalness, effortless control, and a spacious sound image, with a focus on purity and dynamic integrity uncommon in SET amplifiers.