This is 2x 25W JFET-MOSFET class-A single-ended custom amplifier by LJ Audio, with dual input (XLR true balanced or RCA single-ended). Custom made only, approx lead time: 3 weeks.
Model: Aleph J clone Ver #1, Jan 2014 (protoyype).
Adapted from FirstWatt Aleph J by Nelson Pass. The original Aleph J is based on the circuit design of the Aleph series. It is a two stage concept with a p-channel. JFET differential amplifier with a current source at the input and a single ended class A output based on the active current source concept with two identical output stages in parallel.
Aleph J circuit (There are differences between the Aleph J and its predecessors.):
Improved power supply filtration with about 20dB less voltage ripple.
Reduced gain on the active current source, giving better overall performance into 8-16 ohm loads.
Input stage using high quality matched JFETs.
Much higher input impedance and vanishing capacitance.
15dB less negative feedback.
Even greater stability, operating without lag compensation.