I looked at the JRDG Model 5 manual and found the following relevant information:
Damping Factor
Greater than 175, 20 Hz to 20 kHz, 8 ohms
Greater than 60, 100 kHz, 8 ohms
Output Current
40 amps peak, continuous
90 amps peak, 0.1 ohm, 20 msec, 1 kHz
Overall Gain Selectable: 20, 26, 29.5, 32 dB
Sensitivity 36 mV, 1 watt, 8 ohms
Input Impedance Selectable: 100k, 20k, 600 ohms
Common Mode Rejection
Ratio
Greater than 90 dB
Bridged Mono Output
Power
550 watts RMS continuous, 8 ohms
800 watts RMS continuous, 4 ohms
1000 watts RMS continuous, 2 ohms
Interpreting the specs, from a power handling, the JRDG Model 5 should not have major problems handling 2Ohms ribbons, particularly when bridged to mono operations. On the other hand, its damping factor just exceeding 175 may indicate a certain propensity for warmth and perhaps unspecificity in the bass region. G.