The Sympatico Balanced Amplifier
Like the TXO, the Sympatico uses a Burr-Brown OPA1632 fully symmetric op-amp for voltage gain, and a National Semiconductor amplifier chip in a nested feedback loop for additional voltage gain and current drive. Rather than three separate modules and two LM3886 amplifiers of the TXO, the Sympatico is a single small module per channel with one LM4780 dual amplifier chip in a balanced, bridged configuration. Some other design elements of the Sympatico include:
Highlights
Fully symmetric, balanced operation
Ultra-low noise floor (perfect for high efficiency loudspeakers)
100+ Watts/Channel into 8-ohm loads (conservative)
Precision SMD passive components for ultra-short feedback loops (0.5% thin film resistors)
Instrumentation front-end (LM4562) for high input impedance and easy interfacing with single-ended gear (balanced inputs recommended for best performance)
Single user-selectable gain control resistor (through hole)
Through-hole supply capacitors for easy tweaking
On-board discrete shunt voltage regulators for lower voltage stages
Multi-option power and signal connectors (faston, terminal block, direct wire)
Small form-factor (3" x 4")
On board power supply for easy installation