The Sony MDR-CD900ST is 63Ω at 106.0 dB/mW; the Sony MDR-MV1 is 24Ω at 100.0 dB/mW. This page is only about what they ask of an amplifier — not how they sound, which no specification on either sheet can tell you.
The MDR-MV1 needs 6.0 dB more than the MDR-CD900ST to reach the same loudness — 1.0 mW against 0.25 mW.
| Specification | MDR-CD900ST | MDR-MV1 |
|---|---|---|
| Impedance | 63 Ω | 24 Ω |
| Sensitivity | 106.0 dB/mW | 100.0 dB/mW |
| Sensitivity (voltage) | 118.0 dB/V | 116.2 dB/V |
| Power for 100 dB | 0.25 mW | 1.0 mW |
| Voltage for 100 dB | 0.13 V | 0.15 V |
| Current for 100 dB | 2.0 mA | 6.5 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 7.88 Ω | 3.00 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
Every source in the database that drives one of them drives the other. On power, the choice between these two changes nothing about what amplifier you need.
1 source is low enough in output impedance for the MDR-CD900ST under the one-eighth rule but not for the MDR-MV1 (Shanling H5).
280 of the 280 sources here reach 100 dB on both. That count is about power only — the output-impedance and hiss lines above are separate questions, and a source can pass this one and fail those.
Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: Sony MDR-CD900ST and Sony MDR-MV1. Every figure on this page comes from what Sony published, or is derived from it — what that maker publishes, counted.