SSL 2/2+ MKII features many audio performance improvements. You can compare them to the MK I (1st generation) using the table below:
Microphone Inputs
| SSL 2/2+ MKI | SSL 2/2 MKII | |
| Frequency Response | ± 0.1 dB | ± 0.1 dB |
| Dynamic Range (A-Weighted) | 110.5 dB | 116.5 dB |
| THD+N (@ 1kHz) | -96.5 dB | -100 dB |
| EIN (A-Weighted, 150 Ω termination) | -130.5 dBu | -130.5 dBu |
| Maximum Input Level | +5.5 dBu | +9.7 dBu |
| Gain Range | 62 dB | 64 dB |
| Input Impedance | 1.2 kΩ | 1.2 kΩ |
Line Inputs
| SSL 2/2+ MKI | SSL 2/2 MKII | |
| Frequency Response | ± 0.05 dB | ± 0.05 dB |
| Dynamic Range (A-Weighted) | 110.5 dB | 117 dB |
| THD+N (@ 1kHz) | -96.5 dB | -104 dB |
| Maximum Input Level | +24 dBu | +24 dBu |
| Gain Range | 62 dB | 27 dB (deliberately reduced to suit line-level sources) |
| Input Impedance | 10 k Ω | 14 k Ω |
Instrument Inputs
| SSL 2/2+ MKI | SSL 2/2 MKII | |
| Frequency Response | ± 0.05 dB | ± 0.05 dB |
| Dynamic Range (A-Weighted) | 110.5 dB | 116 dB |
| THD+N (@ 1kHz) | -96.5 dB | -99 dB |
| Maximum Input Level | +15 dBu | +15 dBu |
| Gain Range | 62 dB | 64 dB |
| Input Impedance | 1 M Ω | 1 M Ω |
Balanced Outputs
| SSL 2/2+ MKI | SSL 2/2 MKII | |
| Frequency Response | ± 0.05 dB | ± 0.03 dB |
| Dynamic Range (A-Weighted) | 112 dB | 120 dB |
| THD+N (@ 1kHz) | -98 dB | -108 dB |
| Maximum Output Level | +12.5 dBu | +14.5 dBu |
| Output Impedance | 1 Ω | 150 Ω |
Headphone Outputs
| SSL 2/2+ MKI | SSL 2/2 MKII | |
| Frequency Response | ± 0.05 dB | ± 0.05 dB |
| Dynamic Range | 111 dB | 119.5 dB |
| THD+N (@ 1kHz) | -96.5 dB | -106 dB |
| Maximum Output Level | +10 dBu | +13 dBu |
| Output Impedance | 10 Ω | <1 Ω |